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dr_dave
07-14-2005, 01:18 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr>if you have a cut shot and use exactly the right amount of outside english, you can cancel the throw. However, as Ron Shepard has explained, this is probably the least consistent way to hit the shot because it's hard to find exactly the right amount of outside.<hr /></blockquote>
But isn't throw much less consistent than squirt? Now swerve is another matter, so for now I will assume minimal cue stick elevation and a faster shot with the OB not too far from the CB. Even if the outside English is not "perfect," can't it help reduce the throw substantially even if it is close enough to perfect. For dirty balls, or for a CB with chalk marks, throw can vary quite a bit from shot to shot. I personally try to account for throw in my aiming and avoid English where I don't need it, but I have seen many people (even some pros) often use outside English on cue shots, even when they might not need it for position control. What do you think?

Regards,
Dave

raodwarior
07-14-2005, 01:34 PM
I believe that is can be made up for in aiming.

The context of the discussion from me at least was that the aim trainers on the market at present don't account for collision induced throw and that makes it difficult at any kind of distance to make shots. It tends to confuse beginners because even if they do it correctly they still miss.

This comes from my background of teaching mostly beginner and intermediate players and tends to be one of the most difficult concepts for me to get across to them

Fred Agnir
07-14-2005, 02:24 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>But isn't throw much less consistent than squirt? <hr /></blockquote> Yes.

[ QUOTE ]
Now swerve is another matter, so for now I will assume minimal cue stick elevation and a faster shot with the OB not too far from the CB.<hr /></blockquote> To make this assumption makes the rests of the post misleading. Swerve is more of an affect than players care to think about. The whole "I keep the cue as level as possible" doesn't change the fact that your cueball will still swerve, simply because you can't keep your cuestick level on 90+% of shots.

And the affects of swerve are larger than people think.So, when you're going to discuss blending throw with squirt, you absolutely must consider swerve. If not, then there's no reason to discuss the blending of anything, and the shot is reduced to repetition and experience.
Fred

dr_dave
07-14-2005, 02:30 PM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>Now swerve is another matter, so for now I will assume minimal cue stick elevation and a faster shot with the OB not too far from the CB.<hr /></blockquote> To make this assumption makes the rests of the post misleading. Swerve is more of an affect than players care to think about. The whole "I keep the cue as level as possible" doesn't change the fact that your cueball will still swerve, simply because you can't keep your cuestick level on 90+% of shots.

And the affects of swerve are larger than people think.So, when you're going to discuss blending throw with squirt, you absolutely must consider swerve. If not, then there's no reason to discuss the blending of anything, and the shot is reduced to repetition and experience.<hr /></blockquote>
Fred,

Your point is well taken. Does that mean that you agree that, in general, adjusting your aim for throw is a better approach than using outside English to try to cancel or minimize the throw?

Dave

Fred Agnir
07-14-2005, 03:10 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>
You point is well taken. Does that mean that you agree that, in general, adjusting your aim for throw is a better approach than using outside English to try to cancel or minimize the throw?

Dave <hr /></blockquote>I guess I'm confused. Isn't this also what Bob Jewett said? Are you in agreement or disagreement with what he wrote?

In any event, I don't have a good answer. IMO, you need to be able to do both equally well, and be able to judge when you would do one over the other.

Fred

dr_dave
07-14-2005, 03:17 PM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
Your point is well taken. Does that mean that you agree that, in general, adjusting your aim for throw is a better approach than using outside English to try to cancel or minimize the throw?<hr /></blockquote>I don't have a good answer. IMO, you need to be able to do both equally well.<hr /></blockquote>
I would agree with that. But, obviously, it begs the question: When and why would you (or others) use outside English for the sole purpose of eliminating throw (i.e., position control is not an issue). I would think one answer might be "when the balls are really dirty," but I would like to hear what other people think.

Dave

pooltchr
07-14-2005, 05:42 PM
Would you agree that CIT is a result of what takes place during the period of cling on the shot. And if the cling factor is reduced if the cue ball is spinning upon contact, wouldn't any kind of spin produce the same result? Why would it have to be outside english?
(just thought I would throw another wrinkle into the discussion) /ccboard/images/graemlins/wink.gif
Steve

Bob_Jewett
07-14-2005, 06:07 PM
Suppose you play a cut shot as a stun shot. Suppose that you attempt to use side spin to cancel throw. Suppose you have a little more or less side spin than just the right amount to cancel the throw. The object ball will be thrown a little to the left or right of the ideal (frictionless ghost ball) cut line according to the lack or excess of spin.

Plot the angle error of the object ball as a function of the amount of side. Consider the sensitivity of that angle to the amount of side.

Shepard extends this argument to the case of shooting a stop shot. If you tend to have some small random amount of side spin on your shots, a stop shot is the worst possible way to shoot a straight-in. You are much better off playing with a little draw or follow.

dr_dave
07-14-2005, 08:36 PM
<blockquote><font class="small">Quote pooltchr:</font><hr> Would you agree that CIT is a result of what takes place during the period of cling on the shot. And if the cling factor is reduced if the cue ball is spinning upon contact, wouldn't any kind of spin produce the same result? Why would it have to be outside english?
(just thought I would throw another wrinkle into the discussion)<hr /></blockquote>
CIT is due to friction force created between the CB and OB resulting from relative motion between the balls during impact. For more info, see my May '05 instructional article (http://www.engr.colostate.edu/~dga/pool/bd_articles/may05.pdf) and the links under "throw" in the threads summary portion of my website (http://www.engr.colostate.edu/~dga/pool/threads.html). With "gearing" outside English, there is no relative motion between the CB and OB during contact, so there is absolutely no friction and absolutely no throw. In effect, the CB "rolls" on the OB instead of sliding (e.g., see HSV A.8 (http://www.engr.colostate.edu/~dga/pool/high_speed_videos/new/HSVA-8.htm)).

Now, friction is a fairly complicated phenomenon. The proportion of friction force to normal (perpendicular) impact force depends on cut angle, shot speed, the speed of the relative motion during contact, and the ball conditions and cleanliness. Also, the amount of horizontal (throwing) friction depends on the relative amount of sidespin verses top or bottom spin. Throw is largest for a stun shot (with side English). The amount and direction of throw depend on the amount of side English and the cut angle. For small cut angle shots, an excess of outside English (i.e., more than "gearing") will throw the OB one way (e.g., left of the impact line) and inside English will throw the OB the other way (e.g., right of the impact line). So the type of English makes a big difference! For an illustration, see Diagram 1 in my May '05 instructional article (http://www.engr.colostate.edu/~dga/pool/bd_articles/may05.pdf).

Regards,
Dave

dr_dave
07-14-2005, 08:53 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> Suppose you play a cut shot as a stun shot. Suppose that you attempt to use side spin to cancel throw. Suppose you have a little more or less side spin than just the right amount to cancel the throw. The object ball will be thrown a little to the left or right of the ideal (frictionless ghost ball) cut line according to the lack or excess of spin.<hr /></blockquote>
Agreed.

<blockquote><font class="small">Quote Bob_Jewett:</font><hr>Plot the angle error of the object ball as a function of the amount of side. Consider the sensitivity of that angle to the amount of side.<hr /></blockquote>
I don't think anybody has an accurate enough model of friction to get great results here (from just theory), but I'll play along.

<blockquote><font class="small">Quote Bob_Jewett:</font><hr>Shepard extends this argument to the case of shooting a stop shot. If you tend to have some small random amount of side spin on your shots, a stop shot is the worst possible way to shoot a straight-in. You are much better off playing with a little draw or follow.<hr /></blockquote>
I totally agree that stun results in the most throw because the friction force is completely horizontal (in the throwing direction). Now, the part I have a hard time with is that the amount of throw does not depend upon the amount of sidespin (i.e., a miniscule amount of sidespin will create the same amount of throw as a typical shot with intentional English). This is what the Shepard model predicts. Maybe somebody will create a better model (and do lots of actual testing to prove it is valid) in the future. For now, we will just need to make sure to not use stun when we are worried about throw.

Regards,
Dave

Cory
07-14-2005, 08:58 PM
I just recently started using ose on some of my cut shots and noticed a 100% difference in my game.

stickman
07-14-2005, 09:36 PM
Won't BackHandEnglish do what you are trying to accompish? Or am I misunderstanding what you're saying.

Cory
07-14-2005, 10:37 PM
What is backhand english, do you mean outside english?

BCgirl
07-14-2005, 10:47 PM
<hr /></blockquote>
I totally agree that stun results in the most throw because the friction force is completely horizontal (in the throwing direction). Now, the part I have a hard time with is that the amount of throw does not depend upon the amount of sidespin (i.e., a miniscule amount of sidespin will create the same amount of throw as a typical shot with intentional English).
<hr /></blockquote>

I don't really get the concept that the amount of sidespin doesn't affect throw. It's totally contrary to my own observations (though largely unscientific, and possibly flawed).

My own rationalisation of throw is that, for a straight in shot, the amount of throw is a function of english, but there is a limit on how far the ball can be thrown, and no amount of english can throw the ball further. It seems to me that this is limited largely by the contact time. For the sake of argument, you may observe that 90% of throw is achieved with 20% english. The role of contact time is supported by the observation that a soft hit with max english achieves the greatest throw. This is even more apparent when you are trying to throw the second ball in a frozen combination. Hit it fast, no apparent throw. hit it soft, and you can get 10 degrees of throw. Also, larger bar CB's can get greater throw (I think because the differences in diameter creates a collision force that's downward, not flat, increasing both friction and contact time).

I think it's also true that the time that two balls are in contact is longer for a straight shot than a cut shot. If that is true, then when applied to the task of using OSE to cancel CIT, 10% english may achieve the maximum effect in cancelling CIT. That would mean that whether you hit with 10% english, or 90% english is immaterial.

We naturally avoid shots that are sensitive to too many parameters, like a shallow angle pound shot with inside english, because the effects of squirt, throw, speed and english are all significant for both pocketing the ball and position. On the other hand, we gravitate to shots that are less sensitive to errors in some or all of the many possible factors.

Why do many players use OSE when it doesn't appear necessary? Perhaps because they can control the CB trajectory very accurately by varying english, with little effect on aim. At the same time, using OSE helps avoid potential scratches, and allows a more fluid and natural position route.

That's my own rationale FWIW.

BCgirl

stickman
07-15-2005, 04:45 AM
No. To use backhand english, you have to find your pivot point. For my shooting cue, (it's a 60" cue), I use about a 12" to 14" bridge, this is my pivot point. It's not the same for every cue. You lineup the shot with no english. Using the bridge point as a pivot, you move the butt to the right or left, moving the tip to the opposite direction. With the tip to the right, you get righthand english, likewise with the left side. With normal english, you would move the entire cue, along with the bridge, to the left or right. Using extreme english often causes you to miss the shot, unless you compensate the correct amount for the english. No compensation is required for BHE. It takes some trail and error to find your pivot point. For normal shots, I use a shorter bridge. /ccboard/images/graemlins/grin.gif

DickLeonard
07-15-2005, 06:20 AM
Dr. Dave I would play with the ghost ball system when I played. It was accurate when hit with a medium stroke, slow stroke would influence the object ball more and a hard stroke the cueball wouldn't hit the point of aim so adjustment was necessary.

Left hand english you aimed at the contact point,center ball you aimed at the ghost spot and right hand english you aimed at the ghost spot.

I played mostly 14.1, I would say that 90% of my shots were in the bottom four pockets so a hard stroke was not needed.####

dr_dave
07-15-2005, 06:56 AM
<blockquote><font class="small">Quote stickman:</font><hr> Won't BackHandEnglish do what you are trying to accompish? Or am I misunderstanding what you're saying.<hr /></blockquote>
BHE is one method to adjust one's aim to account for squirt, but throw (collision-induced or spin induced) is a different effect that needs to be accounted for on certain shots. For more info, see the links under "English deflection" and "throw" in the threads summary area of my website (http://www.engr.colostate.edu/~dga/pool/threads.html).

Regards,
Dave

dr_dave
07-15-2005, 07:15 AM
<blockquote><font class="small">Quote BCgirl:</font><hr><blockquote><font class="small">Quote dr_dave:</font><hr>I totally agree that stun results in the most throw because the friction force is completely horizontal (in the throwing direction). Now, the part I have a hard time with is that the amount of throw does not depend upon the amount of sidespin (i.e., a miniscule amount of sidespin will create the same amount of throw as a typical shot with intentional English).<hr /></blockquote>
I don't really get the concept that the amount of sidespin doesn't affect throw. It's totally contrary to my own observations (though largely unscientific, and possibly flawed).<hr /></blockquote>
I agree with you. I'm currently working on a model that I think will account for the amount of spin. I hope to post something within a few days.
<blockquote><font class="small">Quote BCgirl:</font><hr>My own rationalisation of throw is that, for a straight in shot, the amount of throw is a function of english, but there is a limit on how far the ball can be thrown, and no amount of english can throw the ball further.<hr /></blockquote>
Sounds good to me. I agree (and I think my model will also agree).
<blockquote><font class="small">Quote BCgirl:</font><hr>It seems to me that this is limited largely by the contact time. For the sake of argument, you may observe that 90% of throw is achieved with 20% english. The role of contact time is supported by the observation that a soft hit with max english achieves the greatest throw. This is even more apparent when you are trying to throw the second ball in a frozen combination. Hit it fast, no apparent throw. hit it soft, and you can get 10 degrees of throw. Also, larger bar CB's can get greater throw (I think because the differences in diameter creates a collision force that's downward, not flat, increasing both friction and contact time).

I think it's also true that the time that two balls are in contact is longer for a straight shot than a cut shot. If that is true, then when applied to the task of using OSE to cancel CIT, 10% english may achieve the maximum effect in cancelling CIT. That would mean that whether you hit with 10% english, or 90% english is immaterial.<hr /></blockquote>
I'm not so sure contact time is an important parameter. And, unfortunately, ball contact times are much too small to easily measure, even with fancy super-high-speed video equipment. So we'll just have to agree to disagree here ... until somebody decides to do a bunch of sophisticated experiments to measure ball contact times for a variety of frozen and nonfrozen shots at various speeds and with various types of English. Impact (and friction) forces are definitely larger for frozen combos, but I'm not so sure contact times would be significantly different.

Regards,
Dave

tateuts
07-15-2005, 07:17 AM
I don't think the experts use outside in order to reduce throw but rather to make it more predictable.

I'm sure everyone has had the wonderful experience a cue ball struck dead center ball on the correct line sending the object ball straight into the rail. A small amount of outside, like 1/4 to 1/2 tip, helps prevent this. at the same time it isn't usually quite enough to make swerve or speed much of a factor.

Chris

dr_dave
07-15-2005, 07:24 AM
<blockquote><font class="small">Quote Cory:</font><hr> What is backhand english, do you mean outside english?<hr /></blockquote>
A description can be found in another thread (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=183506&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;vc=1).

Regards,
Dave

dr_dave
07-15-2005, 07:32 AM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
You point is well taken. Does that mean that you agree that, in general, adjusting your aim for throw is a better approach than using outside English to try to cancel or minimize the throw?<hr /></blockquote>I guess I'm confused. Isn't this also what Bob Jewett said? Are you in agreement or disagreement with what he wrote?<hr /></blockquote>
Are you referring to my response (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200589&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;vc=1) to Bob's message? If so, please let me know where the confusion is. I'm not sure what you are referring to. Also, I am currently working on an improved model of throw that will take more into account than the theory presented separately by Marlow and Shepard (their theories are the same). I'll post something when I have results and a more complete understanding.

Regards,
Dave

dr_dave
07-15-2005, 07:50 AM
<blockquote><font class="small">Quote raodwarior:</font><hr> I believe that is can be made up for in aiming.

The context of the discussion from me at least was that the aim trainers on the market at present don't account for collision induced throw and that makes it difficult at any kind of distance to make shots. It tends to confuse beginners because even if they do it correctly they still miss.

This comes from my background of teaching mostly beginner and intermediate players and tends to be one of the most difficult concepts for me to get across to them<hr /></blockquote>
The aim trainers can be used to learn how to adjust for throw. When you consistently miss a shot with the trainer aligned with the center of the pocket, you can then pivot the trainer to account for throw. This will move the ideal (throwless) ghost-ball target to an adjusted ghost-ball target that accounts for throw. Further adjustments can be made until the OB splits the pocket consistently, with practice. To me, the ghost-ball target is the place the CB needs to be at OB impact to make the shot split the pocket.

Regards,
Dave

DickLeonard
07-15-2005, 08:57 AM
Dr.Dave, AMEN.####

Bob_Jewett
07-15-2005, 11:25 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> ... To me, the ghost-ball target is the place the CB needs to be at OB impact to make the shot split the pocket. ... <hr /></blockquote>
And that's what I call the "corrected ghost ball" to avoid confusion and simultaneously point out to people that the simple ghost ball system needs adjustment. I think the vast majority of players who know about the ghost ball method of aiming have no idea that it needs adjustment even for cut shots without side spin.

stickman
07-15-2005, 01:14 PM
Dave, thanks for the reply. I'm still not sure I can completely visualize the difference, even after reading the definition. I'd be interested in seeing examples of certain shots you referenced. For instance, when shooting a straight in shot with maximum right english, is it throw or squirt that causes you to miss to the left, or maybe both? It seems that dirty balls increase this effect. Using this example, I would set the cueball within an inch of the object ball, to lessen the effect of swerve. Thanks for your time. I'd like to try to understand. /ccboard/images/graemlins/smile.gif

dr_dave
07-15-2005, 01:27 PM
<blockquote><font class="small">Quote stickman:</font><hr>when shooting a straight in shot with maximum right english, is it throw or squirt that causes you to miss to the left, or maybe both? It seems that dirty balls increase this effect. Using this example, I would set the cueball within an inch of the object ball, to lessen the effect of swerve. Thanks for your time. I'd like to try to understand.<hr /></blockquote>
Right English will cause the CB to deflect (squirt) to the left, causing the OB to go to the right. The closer the CB is to the OB, the less this effect will be.

For a slower shot with cue stick elevation (it is always elevated at least a small amount), CB curve (swerve) will be significant and cannot be neglected, especially for higher cue stick elevations. The CB would curve back to the right partly or even more than the squirt to the left.

The right (counterclockwise) spin on the CB will throw the OB to the left. This effect is greater at slower speeds, for dirtier balls, and when the CB has stun (i.e., sliding without rolling at all with no vertical plane spin) at impact. A draw stroke (i.e., bottom-right) is required to achieve stun at impact.

I think that's the whole story. Does it make sense? See the links to discussion topics under "English" and "throw" in the threads summary area of my website (http://www.engr.colostate.edu/~dga/pool/threads.html) for more details.

Regards,
Dave

Cory
07-15-2005, 01:56 PM
i think when i use ose it is just making a slightly fuller hit.i aim exactly for center pocket with 1/2 to 1 cue tip ose does this help or make any sence

stickman
07-15-2005, 02:00 PM
Thanks, Dave. It makes sense now. If, I can only remember. /ccboard/images/graemlins/grin.gif

dr_dave
07-15-2005, 02:07 PM
<blockquote><font class="small">Quote Cory:</font><hr> i think when i use ose it is just making a slightly fuller hit.i aim exactly for center pocket with 1/2 to 1 cue tip ose does this help or make any sence<hr /></blockquote>
Yep ... makes sense to me. The OSE causes squirt, but thow (spin-induced) helps compensate. This should help on most shots; although, the relative amounts of squirt and throw can vary with shot speed, the amount of English (vertical plane and horizontal plane), and cut angle. See my posting telling "the whole story with squirt, swerve, and throw" (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200678&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;vc=1) for more info. The amount of squirt also depends on the type of shaft you are using.

Regards,
Dave

dr_dave
07-15-2005, 02:09 PM
<blockquote><font class="small">Quote stickman:</font><hr> Thanks, Dave. It makes sense now. If, I can only remember. /ccboard/images/graemlins/grin.gif <hr /></blockquote>
You are very welcome. Sorry for all of the lingo, but there's a lot going on.

Regards,
Dave

Jal
07-16-2005, 01:56 AM
<blockquote><font class="small">Quote dr_dave:</font><hr>
I totally agree that stun results in the most throw because the friction force is completely horizontal (in the throwing direction). Now, the part I have a hard time with is that the amount of throw does not depend upon the amount of sidespin (i.e., a miniscule amount of sidespin will create the same amount of throw as a typical shot with intentional English).... <hr /></blockquote>

Some thoughts for what they're worth.

There should be a certain range of spins above and below the exact "gearing" or roll-off spin for which the excess or paucity of spin will be eliminated during the contact period. If you get the spin within this window, the cueball will partly slide and partly roll across the object ball.

The worst case (maximum throw) would be when the spin is at the edge of this range, since the cueball's surface is sliding during the entire contact period, and at the slowest of speeds right down to zero. This assumes that the coefficient of friction increases monotonically with decreasing surface speed (but doesn't vary too much within the window).

However, if the spin is within the center 1/3 or 1/4 of this range (to pick some numbers), then the throw should be greatly reduced since the rolling resistance is very small during the bulk of the contact time.

Outside of this range the amount of throw should decrease as the relative surface speed increases if you accept the premise about the coefficient of friction. I'm not completely sure this is true since tests with balls frozen to each other show increasing throw with increasing cut angle, up to some maximum value at some angle (half-ball or less). I don't know the explanation for this (and would really like one if you or anybody has it).

At any rate, I found the idea of this window to be useful in explaining why a small spin deviation from the exact gearing value doesn't produce much throw. The actual size of the window for small cut angles is surprisingly large (about 90% of the exact rolling spin for a 15 degree cut shot, more if you factor in the coefficient of restitution). Of course you have to get within some fraction of this range to see significant throw reduction, and the size of this window gets smaller as the cut angle increases.

Just some random babble.

Jim

Fred Agnir
07-16-2005, 11:21 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
You point is well taken. Does that mean that you agree that, in general, adjusting your aim for throw is a better approach than using outside English to try to cancel or minimize the throw?<hr /></blockquote>I guess I'm confused. Isn't this also what Bob Jewett said? Are you in agreement or disagreement with what he wrote?<hr /></blockquote>
Are you referring to my response (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200589&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;vc=1) to Bob's message? If so, please let me know where the confusion is. I'm not sure what you are referring to. <hr /></blockquote> I thought my quote and the use of threaded mode should tell you which post I was referring to.

As of this writing, I still can't tell whether or not you agreed with Jewett as far as your first post to this new thread is concerned. You asked him a question that suggested you were questioning his idea of the use of OE to "cancel" throw, yet it looked like you agreed with his stance (that using english to cancel throw might be the least desirable method). So, I'm confused. What's your stance? Do you agree with Bob or disagree? Do you know what Bob's stance is?

And to answer your other question, when the balls are overly dirty or inconsistently dirty, I have to put more emphasis on whatever it takes to pocket the ball. And "relieving the cut" with BHE is my preferred method. Sometimes, you just have to do whatever it takes to get the job done.

With BHE (or Aim and Pivot, if one preferes), there's no need for "how much spin" or "where do I aim" questions if you subscribe to the use of BHE.

Fred

dr_dave
07-16-2005, 03:10 PM
Jim,

Thank you for sharing your thoughts. I had similar thoughts when I started my detailed analysis of throw effects last week. I finally finished the work and the results are described in another thread (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200743&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;fpart=1). Please check it out and let me know if you have any further comments.

One thing I haven't included in the analysis is a model dealing with maximum static friction (during rolling, on the verge of slip) and the smaller dynamic (sliding) friction that takes over once sliding begins. But I'm not sure I (or anybody else) understand the complexities of impact friction enough to accurately model these effects (at least for now).

Regards,
Dave

<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
I totally agree that stun results in the most throw because the friction force is completely horizontal (in the throwing direction). Now, the part I have a hard time with is that the amount of throw does not depend upon the amount of sidespin (i.e., a miniscule amount of sidespin will create the same amount of throw as a typical shot with intentional English).... <hr /></blockquote>

Some thoughts for what they're worth.

There should be a certain range of spins above and below the exact "gearing" or roll-off spin for which the excess or paucity of spin will be eliminated during the contact period. If you get the spin within this window, the cueball will partly slide and partly roll across the object ball.

The worst case (maximum throw) would be when the spin is at the edge of this range, since the cueball's surface is sliding during the entire contact period, and at the slowest of speeds right down to zero. This assumes that the coefficient of friction increases monotonically with decreasing surface speed (but doesn't vary too much within the window).

However, if the spin is within the center 1/3 or 1/4 of this range (to pick some numbers), then the throw should be greatly reduced since the rolling resistance is very small during the bulk of the contact time.

Outside of this range the amount of throw should decrease as the relative surface speed increases if you accept the premise about the coefficient of friction. I'm not completely sure this is true since tests with balls frozen to each other show increasing throw with increasing cut angle, up to some maximum value at some angle (half-ball or less). I don't know the explanation for this (and would really like one if you or anybody has it).

At any rate, I found the idea of this window to be useful in explaining why a small spin deviation from the exact gearing value doesn't produce much throw. The actual size of the window for small cut angles is surprisingly large (about 90% of the exact rolling spin for a 15 degree cut shot, more if you factor in the coefficient of restitution). Of course you have to get within some fraction of this range to see significant throw reduction, and the size of this window gets smaller as the cut angle increases.

Just some random babble.

Jim<hr /></blockquote>

dr_dave
07-16-2005, 03:15 PM
Fred,

I finally finished my thorough analysis of throw effects. Please check out my results and conclusions in the new thread (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200743&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;fpart=1). To answer your question, I do agree with Bob, except concerning the extreme sensitivity to small amounts of sidespin in straight-on stun shots. I address this issue in the new thread. Please check it out. I look forward to comments from you and Bob.

Regards,
Dave

<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
Your point is well taken. Does that mean that you agree that, in general, adjusting your aim for throw is a better approach than using outside English to try to cancel or minimize the throw?<hr /></blockquote>I guess I'm confused. Isn't this also what Bob Jewett said? Are you in agreement or disagreement with what he wrote?<hr /></blockquote>
Are you referring to my response (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200589&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;vc=1) to Bob's message? If so, please let me know where the confusion is. I'm not sure what you are referring to. <hr /></blockquote> I thought my quote and the use of threaded mode should tell you which post I was referring to.

As of this writing, I still can't tell whether or not you agreed with Jewett as far as your first post to this new thread is concerned. You asked him a question that suggested you were questioning his idea of the use of OE to "cancel" throw, yet it looked like you agreed with his stance (that using english to cancel throw might be the least desirable method). So, I'm confused. What's your stance? Do you agree with Bob or disagree? Do you know what Bob's stance is?

And to answer your other question, when the balls are overly dirty or inconsistently dirty, I have to put more emphasis on whatever it takes to pocket the ball. And "relieving the cut" with BHE is my preferred method. Sometimes, you just have to do whatever it takes to get the job done.

With BHE (or Aim and Pivot, if one preferes), there's no need for "how much spin" or "where do I aim" questions if you subscribe to the use of BHE.

Fred <hr /></blockquote>

Jal
07-17-2005, 11:15 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>... I had similar thoughts when I started my detailed analysis of throw effects last week. I finally finished the work...
<blockquote><font class="small">Quote Jal:</font><hr> ...There should be a certain range of spins above and below the exact "gearing" or roll-off spin for which the excess or paucity of spin will be eliminated during the contact period.... The actual size of the window for small cut angles is surprisingly large (about 90% of the exact rolling spin for a 15 degree cut shot...<hr /></blockquote> <hr /></blockquote>

I was glad to see that you didn't think the idea complete gobblygook and had already pursued a similar line of reasoning. Congratulations on finishing it. I started reading it but found that I'll have to backtrack a bit to get oriented. Since it can take several hours for me these days to go from y/a=x to y=ax, it may take awhile.

I want to make a correction to something I said in the original post, which was that the size of the window for a 15 deg cut shot is about 90% of the exact roll-off spin. It's much bigger I think. The 90% value was arrived at treating the object ball as stationary. When its throw and spin are taken into account, the relative surface speed is greatly reduced making it much "easier" for the sliding friction to bring the cueball into a rolling state.

However, I'm not going to venture any more numbers until I read your treatment to see if my simple one bears any resemblence (results-wise).

It's really great that men like you and Ron Shepard and Bob Jewett offer up your hard won conclusions so freely for the rest of us. Thank you, thank you and thank you!

Jim

Rod
07-17-2005, 11:54 PM
I suppose there are arguements for either, doesn't matter. A good pool player adjusts for either. Your aim, in any situation should include descrepancies. Pool players adjust for conditions. Personally I think its moot.

Rod

SpiderMan
07-18-2005, 09:54 AM
Dave,

I've thought about this quite a bit, and tried compensation experiments with both aim and english. I'll chime in on the side favoring english to cancel throw.

Here's my logic:

The amount of throw is dependent on friction (both ball/ball and ball/cloth), ie it will vary with surface conditions. These surface conditions may even vary greatly across the surface of a ball, ie the contact point may have a chalk mark or other irregularity.

If I compensate by varying my aim (cutting thinner), I must guess at the amount of "cling" throw (borrowing a Bob Byrne term) this particular collision will generate. Usually, I guess close enough.

If I compensate by using outside english, there is reduced variability due to surface conditions, because the ball surfaces have reduced relative tangential motion at contact. Applying outside english does require aim adustment for cueball squirt, but this is relatively constant compared with the surface variability I am avoiding.

Experimenting at the table (many tables) also indicates that I can more consistently judge cueball squirt than random cling throw, ie I'm much more likely to cinch the shot if I use outside english rather than a thinner cut.

A "minus" of outside-english throw cancellation is that it limits positional options, so there are situations where it is not the correct answer.

Bottom line is that position play will often require you to make the necessary adjustments to pocket the ball regardless of english chosen. But, if there are no other constraints on your choices, outside seems to yield the most consistent shotmaking.

SpiderMan

<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Bob_Jewett:</font><hr>if you have a cut shot and use exactly the right amount of outside english, you can cancel the throw. However, as Ron Shepard has explained, this is probably the least consistent way to hit the shot because it's hard to find exactly the right amount of outside.<hr /></blockquote>
But isn't throw much less consistent than squirt? Now swerve is another matter, so for now I will assume minimal cue stick elevation and a faster shot with the OB not too far from the CB. Even if the outside English is not "perfect," can't it help reduce the throw substantially even if it is close enough to perfect. For dirty balls, or for a CB with chalk marks, throw can vary quite a bit from shot to shot. I personally try to account for throw in my aiming and avoid English where I don't need it, but I have seen many people (even some pros) often use outside English on cue shots, even when they might not need it for position control. What do you think?

Regards,
Dave <hr /></blockquote>

Fran Crimi
07-18-2005, 10:19 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote stickman:</font><hr> Won't BackHandEnglish do what you are trying to accompish? Or am I misunderstanding what you're saying.<hr /></blockquote>
BHE is one method to adjust one's aim to account for squirt, but throw (collision-induced or spin induced) is a different effect that needs to be accounted for on certain shots. For more info, see the links under "English deflection" and "throw" in the threads summary area of my website (http://www.engr.colostate.edu/~dga/pool/threads.html).

Regards,
Dave <hr /></blockquote>


Dave,

When was it decided that the purpose of BHE was to adjust your aim to account for cb squirt? As far back as I can recall, it was always considered a tool for minimizing cb squirt.

Fran

Fred Agnir
07-18-2005, 11:05 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> Dave,


adjust your aim to account for cb squirt?

a tool for minimizing cb squirt.

Fran <hr /></blockquote>As far as I can see, these two are essentially the same, with semantics being the only devil.

Fred

Fran Crimi
07-18-2005, 11:25 AM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> Dave,


adjust your aim to account for cb squirt?

a tool for minimizing cb squirt.

Fran <hr /></blockquote>As far as I can see, these two are essentially the same, with semantics being the only devil.

Fred <hr /></blockquote>

I think they're completely different.

Fran

Jal
07-18-2005, 12:19 PM
<blockquote><font class="small">Quote SpiderMan:</font><hr> ...The amount of throw is dependent on friction (both ball/ball and ball/cloth)...<hr /></blockquote>

Yeah, I know it's nit picking, but I don't think the amount of throw depends to any significant extent on ball/cloth friction. The normal forces between the balls can range up into the thousands of pounds but the cueball weighs only about a third of a pound. Since the magnitude of the frictional forces are their respective coefficients of friction multiplied by these normal forces, there would have to be a vast difference in the values of the coefficients to make them comparable. But they're not that far apart (approx. 0.2 for the ball/cloth and 0.05 for the ball/ball).

<blockquote><font class="small">Quote SpiderMan:</font><hr>
If I compensate by varying my aim (cutting thinner), I must guess at the amount of "cling" throw (borrowing a Bob Byrne term) this particular collision will generate. Usually, I guess close enough.

If I compensate by using outside english, there is reduced variability due to surface conditions, because the ball surfaces have reduced relative tangential motion at contact. Applying outside english does require aim adustment for cueball squirt, but this is relatively constant compared with the surface variability I am avoiding.

Experimenting at the table (many tables) also indicates that I can more consistently judge cueball squirt than random cling throw, ie I'm much more likely to cinch the shot if I use outside english rather than a thinner cut.

A "minus" of outside-english throw cancellation is that it limits positional options, so there are situations where it is not the correct answer.

Bottom line is that position play will often require you to make the necessary adjustments to pocket the ball regardless of english chosen. But, if there are no other constraints on your choices, outside seems to yield the most consistent shotmaking.
<hr /></blockquote>

It's hard to argue with what works for you but it seems like a questionable strategy to me. I just don't think there's that much variation in the condition of ball's surfaces and to do this successfully you have to adjust for swerve, where more variations are likely to occur.

Just my opinion.

Jim

SPetty
07-18-2005, 01:16 PM
<blockquote><font class="small">Quote Jal:</font><hr> The normal forces between the balls can range up into the thousands of pounds ...<hr /></blockquote>Can you elaborate on that a little more? Thousands of pounds?

SpiderMan
07-18-2005, 01:36 PM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr> ...The amount of throw is dependent on friction (both ball/ball and ball/cloth)...<hr /></blockquote>

Yeah, I know it's nit picking, but I don't think the amount of throw depends to any significant extent on ball/cloth friction. The normal forces between the balls can range up into the thousands of pounds but the cueball weighs only about a third of a pound. Since the magnitude of the frictional forces are their respective coefficients of friction multiplied by these normal forces, there would have to be a vast difference in the values of the coefficients to make them comparable. But they're not that far apart (approx. 0.2 for the ball/cloth and 0.05 for the ball/ball). <hr /></blockquote>

Jim,

Try this experiment - find a poolroom with both a slick simonis table and a nappy table. Using the same two balls, see how much collision-induced throw you can observe on each table.

SpiderMan

SpiderMan
07-18-2005, 01:41 PM
Susan,

I believe he's estimating acceleration from an assumed change in velocity divided by an assumed contact time. Small contact time in the denominator gives large acceleration, then F=mA where m is ball mass.

SpiderMan

Jal
07-18-2005, 03:05 PM
<blockquote><font class="small">Quote SPetty:</font><hr> <blockquote><font class="small">Quote Jal:</font><hr> The normal forces between the balls can range up into the thousands of pounds ...<hr /></blockquote>Can you elaborate on that a little more? Thousands of pounds? <hr /></blockquote>

The object ball gets accelerated to speed during a very brief period of time. While I don't know the exact length of this time, I've read about one ten-thousandth of a second (perhaps two?) In order to achieve the acceleration sufficient to bring the object ball up to typical speeds during this short period, the average force acting on it must be rather large.

It's a consequence of a variation of the formula F=ma: F=^mv/^t where ^mv is the change in the momentum (mass times velocity) of the object ball, and ^t is the time during which this takes place.

So for a half-ball hit (30 degree cut angle), with the cueball traveling at a somewhat moderate speed of say 10 mph, an average force of about 1500 pounds will be exerted, (using 1/10000 second as the impact time).

Of course, if your finger happens to be between the two balls, it will not experience anywhere near this amount of force because the ramp up in speed of the object ball will occur over a much longer period of time.

I hope that explains it (and that I got it right).

Jim

Jal
07-19-2005, 01:15 PM
<blockquote><font class="small">Quote SpiderMan:</font><hr> <blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr> ...The amount of throw is dependent on friction (both ball/ball and ball/cloth)...<hr /></blockquote>

Yeah, I know it's nit picking, but I don't think the amount of throw depends to any significant extent on ball/cloth friction. ...<hr /></blockquote>

Jim,

Try this experiment - find a poolroom with both a slick simonis table and a nappy table. Using the same two balls, see how much collision-induced throw you can observe on each table.

SpiderMan <hr /></blockquote>

From the context of the thread I think I had stun shots more or less in mind when I made the statement. Or maybe (to be a little more honest), just wasn't thinking about the possible exceptions.

When the cueball has a little more follow on it than sidespin and the cut angle isn't too great, then the cloth friction definitely does come into play. With topspin the object ball is driven into the table with a force many times its weight, and if something like the above conditions are in effect, then the cloth friction is comparable and will even exceed the sideways component of the ball/ball friction under some circumstances.

Since many shots come under this category, it's can't be dismissed as readily as I suggested.

Jim

dr_dave
07-19-2005, 01:54 PM
Spiderman,

Thank you for your perspectives ... as usual, very insightful and thorough. I've also been thinking about this a lot, as you can probably tell from
my posting concerning the complete analysis of throw effects (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=200743&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;fpart=1). I agree that squirt is much more repeatable, especially if you use the same amount of English (and speed?) (and, obviously, cue stick) each time. So from now on, if I have a cut shot where position control is not critical or adversely affected, I will strongly consider using outside English (and squirt aim adjustment) to minimize throw instead of adjusting my aim to account for collision-induced throw.

Regards,
Dave

<blockquote><font class="small">Quote SpiderMan:</font><hr> Dave,

I've thought about this quite a bit, and tried compensation experiments with both aim and english. I'll chime in on the side favoring english to cancel throw.

Here's my logic:

The amount of throw is dependent on friction (both ball/ball and ball/cloth), ie it will vary with surface conditions. These surface conditions may even vary greatly across the surface of a ball, ie the contact point may have a chalk mark or other irregularity.

If I compensate by varying my aim (cutting thinner), I must guess at the amount of "cling" throw (borrowing a Bob Byrne term) this particular collision will generate. Usually, I guess close enough.

If I compensate by using outside english, there is reduced variability due to surface conditions, because the ball surfaces have reduced relative tangential motion at contact. Applying outside english does require aim adustment for cueball squirt, but this is relatively constant compared with the surface variability I am avoiding.

Experimenting at the table (many tables) also indicates that I can more consistently judge cueball squirt than random cling throw, ie I'm much more likely to cinch the shot if I use outside english rather than a thinner cut.

A "minus" of outside-english throw cancellation is that it limits positional options, so there are situations where it is not the correct answer.

Bottom line is that position play will often require you to make the necessary adjustments to pocket the ball regardless of english chosen. But, if there are no other constraints on your choices, outside seems to yield the most consistent shotmaking.

SpiderMan

<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Bob_Jewett:</font><hr>if you have a cut shot and use exactly the right amount of outside english, you can cancel the throw. However, as Ron Shepard has explained, this is probably the least consistent way to hit the shot because it's hard to find exactly the right amount of outside.<hr /></blockquote>
But isn't throw much less consistent than squirt? Now swerve is another matter, so for now I will assume minimal cue stick elevation and a faster shot with the OB not too far from the CB. Even if the outside English is not "perfect," can't it help reduce the throw substantially even if it is close enough to perfect. For dirty balls, or for a CB with chalk marks, throw can vary quite a bit from shot to shot. I personally try to account for throw in my aiming and avoid English where I don't need it, but I have seen many people (even some pros) often use outside English on cue shots, even when they might not need it for position control. What do you think?

Regards,
Dave <hr /></blockquote> <hr /></blockquote>

dr_dave
07-19-2005, 02:09 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr>When was it decided that the purpose of BHE was to adjust your aim to account for cb squirt? As far back as I can recall, it was always considered a tool for minimizing cb squirt.<hr /></blockquote>
Fran,

If you aim a shot through center ball and shift your stick left to apply left English (keeping the cue stick parallel to the aiming line), squirt will cause the CB to go right of the aiming line. BHE, as I understand it, corrects for this by pivoting the cue stick left about the bridge hand (from the center ball position). The cue stick is now aimed to the left of the target so squirt will send the CB back on line to the target. Therefore, to me, BHE is changing the aiming line of the cue stick to account for squirt. BHE does not limit or minimize squirt, it just changes the aiming line so the CB squirts in the desired direction.

As Fred points out, this is probably just a semantics issue.

Regards,
Dave

Fran Crimi
07-19-2005, 03:51 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>
If you aim a shot through center ball and shift your stick left to apply left English (keeping the cue stick parallel to the aiming line), squirt will cause the CB to go right of the aiming line. BHE, as I understand it, corrects for this by pivoting the cue stick left about the bridge hand (from the center ball position). The cue stick is now aimed to the left of the target so squirt will send the CB back on line to the target. Therefore, to me, BHE is changing the aiming line of the cue stick to account for squirt. BHE does not limit or minimize squirt, it just changes the aiming line so the CB squirts in the desired direction.

As Fred points out, this is probably just a semantics issue.

Regards,
Dave <hr /></blockquote>

OK. What you're saying makes sense to me. I think I may have an old school interpretation of it that probably needs updating.

See...the way I was taught is that BHE allows the shooter to shoot closer to the center of the CB and obtain the same amount of side spin as you would by moving your cue stick farther out on the CB on a parallel line, thus, reducing CB squirt. It was looked on as more of an english application technique rather than a squirt compensation technique.

For example, if on a particular shot, you would ordinarily use 2 tips of right english with a parallel cue stick placement, BHE would enable you to use one tip and accomplish the same result. That results in reduced cb squirt because you're striking the cb closer to the center. That's why I was focusing on it as not an aiming technique but rather a squirt reduction technique.

Fran

SpiderMan
07-19-2005, 05:03 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
If you aim a shot through center ball and shift your stick left to apply left English (keeping the cue stick parallel to the aiming line), squirt will cause the CB to go right of the aiming line. BHE, as I understand it, corrects for this by pivoting the cue stick left about the bridge hand (from the center ball position). The cue stick is now aimed to the left of the target so squirt will send the CB back on line to the target. Therefore, to me, BHE is changing the aiming line of the cue stick to account for squirt. BHE does not limit or minimize squirt, it just changes the aiming line so the CB squirts in the desired direction.

As Fred points out, this is probably just a semantics issue.

Regards,
Dave <hr /></blockquote>

OK. What you're saying makes sense to me. I think I may have an old school interpretation of it that probably needs updating.

See...the way I was taught is that BHE allows the shooter to shoot closer to the center of the CB and obtain the same amount of side spin as you would by moving your cue stick farther out on the CB on a parallel line, thus, reducing CB squirt. It was looked on as more of an english application technique rather than a squirt compensation technique.

For example, if on a particular shot, you would ordinarily use 2 tips of right english with a parallel cue stick placement, BHE would enable you to use one tip and accomplish the same result. That results in reduced cb squirt because you're striking the cb closer to the center. That's why I was focusing on it as not an aiming technique but rather a squirt reduction technique.

Fran <hr /></blockquote>

Fran, Dave - I believe there actually are two distinct methods common for implementing "back-hand english".

The contemporary approach, as described by Dr Dave and many posters on this board (and on RSB), is to recognize it as a correction for the CB "squirt" angle. Such practitioners tend to line up their shot while addressing the cue centerball, then pivot the stick (with the bridge as a fixed fulcrum point) until their point of address on the cueball is offset correctly to apply their english. Once properly aligned, they then stroke the shot by moving the cue pretty much in a straight line.

There are many players, particularly old-timers, who apply BHE in a different manner. They, too, line up the shot with centerball (no english), but do not re-aim in a conscious intermediate step. Instead they "swoop" the butt of the cue sideways during their final delivery, producing the tip offset on the cueball.

The end effect of both techniques is english applied with squirt correction. I expect the old-time "swooping" players, being in general a less analytic bunch, did indeed see this as an application technique. To their observation, the CB seemed to go "straight" despite applying spin, which wasn't the case if they offset their cue. I'm guessing a little here, but perhaps many of them thought that, since the aim seemed to be unperturbed, they were actually getting their english by wiping the tip across the cueball, and somehow avoiding the squirt that comes with lining up offset.

Fran, were you initially shown this technique by an old-school "feel" player who would "swoop" the butt of the cue?

SpiderMan

Fran Crimi
07-19-2005, 09:09 PM
Your theory is based on the assumption that every person who used the swipe method for the purpose of reducing cb squirt, in the history of the game, believed that they were striking the ball closer to center than they really were. I'm not saying you're wrong, but I'd rather wait for proof.

The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?

Some additional information on the "swipe" method..unlike the pivot method, the cue stick angle of attack is straight, up to the point of contact.

Fran

Jal
07-20-2005, 02:27 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> ....The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?...<hr /></blockquote>

I can only tell you this much for certain: you're going to get negative squirt, that is, squirt to the right if you're trying to produce right english. It's so fundamental though I can't offer you any proof.

Even if you make contact off center on the right side in the just mentioned case, you're still going to get negative squirt unless the cue's pivot point is forward of the bridge hand.

Sorry, but that's all I can say.

Jim

SpiderMan
07-20-2005, 05:02 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?<hr /></blockquote>

In that case, you would not really be striking the cueball "at center". Unless the cue tip is moving toward the CB center of mass (geometric center) at the brief moment of contact, it's an off-center hit. Regardless of the location of the contact point, any non-perpendicular component of relative motion (as in the "swoop") equates to an off-center hit.

SpiderMan

Fred Agnir
07-20-2005, 05:58 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?

Some additional information on the "swipe" method..unlike the pivot method, the cue stick angle of attack is straight, up to the point of contact.

Fran <hr /></blockquote>I think a simple video will show what your actual position is when you contact the ball if you are using what I call "dynamic backhand english" (swooping/swiping). I would guess that at contact, you are no longer hitting as close to center ball as the old timers are suggesting. That is, the end effect would be the same as if you initially pivoted before aiming.

Fred

Fran Crimi
07-20-2005, 07:05 AM
<blockquote><font class="small">Quote SpiderMan:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?<hr /></blockquote>

In that case, you would not really be striking the cueball "at center". Unless the cue tip is moving toward the CB center of mass (geometric center) at the brief moment of contact, it's an off-center hit. Regardless of the location of the contact point, any non-perpendicular component of relative motion (as in the "swoop") equates to an off-center hit.

SpiderMan <hr /></blockquote>


Off center is fine. The question is whether you can attain the same amount of spin as with a parallel cue placement further out on the cb. That would result in equal amounts of spin but with reduced cb squirt. That's my question.

Fran

Fran Crimi
07-20-2005, 07:15 AM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> ....The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?...<hr /></blockquote>

I can only tell you this much for certain: you're going to get negative squirt, that is, squirt to the right if you're trying to produce right english. It's so fundamental though I can't offer you any proof.

Even if you make contact off center on the right side in the just mentioned case, you're still going to get negative squirt unless the cue's pivot point is forward of the bridge hand.

Sorry, but that's all I can say.

Jim
<hr /></blockquote>

Negative squirt. That's interesting.

It's sort of a two-part question: but can you achieve spin by contacting the cb slightly to the side of center with the swipe method, that equals the amount of spin applied with a parallel cue stick placement farther out on the cb?

Fran

dr_dave
07-20-2005, 08:22 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?<hr /></blockquote>

In that case, you would not really be striking the cueball "at center". Unless the cue tip is moving toward the CB center of mass (geometric center) at the brief moment of contact, it's an off-center hit. Regardless of the location of the contact point, any non-perpendicular component of relative motion (as in the "swoop") equates to an off-center hit.

SpiderMan <hr /></blockquote>


Off center is fine. The question is whether you can attain the same amount of spin as with a parallel cue placement further out on the cb. That would result in equal amounts of spin but with reduced cb squirt. That's my question.

Fran <hr /></blockquote>
Fran,

What Spiderman wrote makes sense. The CB doesn't care how the tip is delivered to the ball. The only thing it cares about is the speed, the total velocity direction (from forward and sideways motion), and the amount of offset from center measured from the line of action of the total tip velocity. With a swoop, it will appear to the shooter that they are hitting the CB closer to center, but in reality (from the CB's perspective), they are effectively hitting further off center. A straight stroke with a center offset equal to the effective center offset of a swoop shot will generate the same amount of spin and squirt; although, the two shots might look (and certainly feel) quite different to the shooter. I think the swoop shot is certainly more difficult to execute accurately and repeatedly.

Are there any instructors out there still teaching the "old-school" backhand "swoop" method of magical squirt reduction? I, personally, would not recommend this.

Regards,
Dave

SpiderMan
07-20-2005, 08:30 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?<hr /></blockquote>

In that case, you would not really be striking the cueball "at center". Unless the cue tip is moving toward the CB center of mass (geometric center) at the brief moment of contact, it's an off-center hit. Regardless of the location of the contact point, any non-perpendicular component of relative motion (as in the "swoop") equates to an off-center hit.

SpiderMan <hr /></blockquote>


Off center is fine. The question is whether you can attain the same amount of spin as with a parallel cue placement further out on the cb. That would result in equal amounts of spin but with reduced cb squirt. That's my question.

Fran <hr /></blockquote>

I think you can get the same amount of spin. I can't personally, because I don't practice the "swoop" technique, but I have two acquaintances who are proficient at it. I see no significant difference in achievable results between my friends' swooping and my own linear-stroked BHE. I think it's just two distinct ways to achieve similar dynamics, ie we both get equal negation of the squirt by having the aim off-line at contact.

I don't believe you get any inherent reduction in squirt by swooping, ie practitioners don't appear to me to be any closer to centerball alignment at contact. Of course, it's pretty hard to see, but I think that it's correcting the aim by having the cue off-line at contact, for an overall compensating effect pretty indistinguishable from linear-stroked BHE.

As Fred noted, you'd need some good videography to really document this, but if the common estimate of dwell time in the millisecond range is accurate it would be unlikely the swoop has much of a "wiping" effect. That would be akin to saying that a follow-through could influence post-contact behavior, which has been theoretically and experimentally disproven to the satisfaction of most. If the previous is true, then the spin must come from an off-center hit, not a "wipe-and-drag".

Maybe Dr Dave would like to try capturing a swoop stroke on video at one of his sessions.

SpiderMan

Fran Crimi
07-20-2005, 08:30 AM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> I think a simple video will show what your actual position is when you contact the ball if you are using what I call "dynamic backhand english" (swooping/swiping). I would guess that at contact, you are no longer hitting as close to center ball as the old timers are suggesting. That is, the end effect would be the same as if you initially pivoted before aiming.

Fred <hr /></blockquote>

That would only be partially helpful. Since this is a squirt reduction theory, comparisons need to be made.

One would be in measuring amount of cb squirt by striking the cb at the exact same point using pivotal BHE, swipe BHE and parallel stick placement english.

The second would be to measure the amount of english applied by studying the motion of the cb after contact with the ob, off of a rail or multi rails, using all three methods. (There are actually more methods but these three would provide some good basic information.)

I don't think we should toss away a theory that's been around for a century that may not have been technologically discovered yet. The theory could be wrong, but I think it deserves to be tested. If it's already been tested, then let's see the proof.

Fran

Additional edit note: In the second suggestion, I'd like to see english compared with each method striking the cb in various places. It wouldn't be impossible to imagine that with the swipe method, there may be diminishing returns the farther out on the cue ball you go.

dr_dave
07-20-2005, 09:14 AM
<blockquote><font class="small">Quote SpiderMan:</font><hr>Maybe Dr Dave would like to try capturing a swoop stroke on video at one of his sessions.<hr /></blockquote>
I will add it to my list and try to film some. I'm setting up at a pool hall in Fort Collins this afternoon, and a bunch of old-timers hang out there. Maybe I can find some swoopers in the crowd.

I have been fortunate to have two top notch players helping me with some of the filming. We're filming a bunch of jumps, masse shots, and power breaks later today.

Regards,
Dave

Fran Crimi
07-20-2005, 09:16 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr>Maybe Dr Dave would like to try capturing a swoop stroke on video at one of his sessions.<hr /></blockquote>
I will add it to my list and try to film some. I'm setting up at a pool hall in Fort Collins this afternoon, and a bunch of old-timers hang out there. Maybe I can find some swoopers in the crowd.

I have been fortunate to have two top notch players helping me with some of the filming. We're filming a bunch of jumps, masse shots, and power breaks later today.

Regards,
Dave <hr /></blockquote>

Great, Dave! Read my response to Fred and see if it makes sense to incorporate some of my ideas into your filming.

Thanks,
Fran

Bob_Jewett
07-20-2005, 10:55 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> ... But isn't throw much less consistent than squirt? ... <hr /></blockquote>
I don't think so. Of course, there is the occasional bad contact (skid, cling, kick) in which throw increases by many times, but for a particular cue and object ball and spin conditions, I think throw is very predictable. To see an amazing demonstration of a master of throw, get the www.kozoom.com (http://www.kozoom.com) DVD of the 2003 World 18.2 (47/2) Championships.

http://www.kozoom.com/fr/general/boutique_billard/produits/18/

Don't worry about the French -- the DVD has English commentary as well. In the two matches shown, Frederic Caudron manipulates the balls with an accuracy that makes Efren Reyes look like a ham-fisted lumberjack. Many of those shots are impossible without throw and transfer of side spin to the object ball.

Rod
07-20-2005, 11:28 AM
Nothing long and dramatic here. I think there both very predictable. Problem is, you have to recognize conditions where one may work better than another. It's always been that way. You'll be hard pressed to get me to admit one is better than another unless conditions warrant use of either.

[ QUOTE ]
I personally try to account for throw in my aiming and avoid English where I don't need it, but I have seen many people (even some pros) often use outside English on cue shots, even when they might not need it for position control. What do you think?
<hr /></blockquote>

Now I'm off to do my laundry, UGG. I'll drop over to the pool room and knock some balls around. There I will use throw from english in most cases even if it's not warranted. Why? because conditions dictate how the game is played.


Rod

Jal
07-20-2005, 11:45 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> ....The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?...<hr /></blockquote>

I can only tell you this much for certain: you're going to get negative squirt, that is, squirt to the right if you're trying to produce right english. It's so fundamental though I can't offer you any proof.

Even if you make contact off center on the right side in the just mentioned case, you're still going to get negative squirt unless the cue's pivot point is forward of the bridge hand.

Sorry, but that's all I can say.

Jim
<hr /></blockquote>

Negative squirt. That's interesting.

It's sort of a two-part question: but can you achieve spin by contacting the cb slightly to the side of center with the swipe method, that equals the amount of spin applied with a parallel cue stick placement farther out on the cb?

Fran <hr /></blockquote>

I don't think I agree with Spiderman and Dr. Dave about the real vs apparent offset due to the sideways motion of the tip, but let me first explain why I believe you'll get negative squirt.

Let's say you set up at some offset with static parallel aiming and then swoop across the contact point in an attempt to eliminate the squirt. I think it's possible to do this, in principle, because you are then eliminating the cause of the squirt, which is the reaction of the cueball as it pushes the cue's tip (endmass) to the side. In effect, you're supplying this sideways motion and relieving the cueball of the job.

However, I did some rough calculations to see at what angle from straight ahead you would have to push the cue with your grip hand to get the necessary rotation of the cue, and except for very modest offsets from centerball, it's very impractical to attempt even half the necessary rotation. But the caveat is that these were 'rough' calculations.

Now, with the above in mind, suppose you set up for centerball and swoop to make contact at some offset. If the cue's pivot point is in right at your bridge hand, you will get all of the squirt compensation from just the angle of the cue at contact (as in static BHE), but in addition to this you'll get a little more squirt reduction from the sideways motion, thus negative squirt. And, of course, if the pivot point is behind your bridge hand, you'll get negative squirt anyway. (I'm using "negative squirt" here to indicate motion away from the intended line of the shot.)

If you hit the cueball at center while swooping, any transverse force which rotates the cueball will necessarily propel the cueball sideways too. Again, negative squirt. The amount of squirt would depend on the ratio of the tips sideways speed to it's forward motion. It's here that I disagree with Dr. Dave an Spiderman (God knows it probably won't take them long to set my mind right). I think that the phenomenon of the relatively slow moving transverse wave vs the fast compression wave rears its ugly head, making the simple combination of the two component motions, invalid. Otherwise you could treat it as a ball/ball collision with changes in the appropriate parameters (moment of inertia and coefficient of friction). But I don't know how to handle the problem and can't offer anything more at the moment.

Jim

Fran Crimi
07-20-2005, 01:31 PM
So based on your theory, it's conceivable that negative squirt could potentially cancel or minimize positive squirt, depending on the forward/side force ratio.

I will say that strictly from a playing perspective, that's what feels like is happening, and I'm sure it felt that way to others before me.

I hope that you or anyone can test some calculations to explore this possibility.

Thanks,
Fran

BigRigTom
07-20-2005, 03:55 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> So based on your theory, it's conceivable that negative squirt could potentially cancel or minimize positive squirt, depending on the forward/side force ratio.

I will say that strictly from a playing perspective, that's what feels like is happening, and I'm sure it felt that way to others before me.

I hope that you or anyone can test some calculations to explore this possibility.

Thanks,
Fran <hr /></blockquote>

Fran at the risk of being a smart ass /ccboard/images/graemlins/cool.gif...If...
Positive squirt + Negative squirt = Zero squirt and you can achieve that why would you want to?
Aren't there other things that would be more beneficial to the advancement of skills and have a bigger cost/benefit ratio? /ccboard/images/graemlins/confused.gif

Jal
07-20-2005, 03:58 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> So based on your theory, it's conceivable that negative squirt could potentially cancel or minimize positive squirt, depending on the forward/side force ratio....<hr /></blockquote>

I'm using "squirt" in a general sense to mean any deviation from the intended line of the shot due to the interaction between the stick and cueball. And by "negative" squirt I mean having the cueball move to the same side as the english (as opposed to normal or positive squirt in which it moves to the opposite side). This is not standard usage and was meant as a shorthand. I apologize for the confusion and should have made this clear a few posts ago.

As I see it, the only case where you could reduce the positive squirt is in the parallel aiming case where you swoop across the contact point. I have no "inside" knowledge of this other than the argument I gave above.

On the other hand, if you're lined up at centerball and swoop to hit at some offset, and the cue's squirt pivot point is at or behind your bridge hand, then I think you'll end up with a net negative squirt (because the sideways motion of the tip will partially cancel the positive squirt which is already compensated for). It probably won't be much when the bridge is at the pivot point, and as Spiderman has said it's essentially a dynamic version of static BHE.

The case of hitting centerball is more subtle and as I said I don't really know how to calculate the forces. I'm pretty certain you'll end up with negative squirt here too, and in proportion to the spin you get on the ball and relative to the cue's forward speed.

At any rate I hope the arguments for the other cases are clear enough that you or someone can confirm or reject them. I know you want some numbers or more substantial proof but I don't feel confident enough to supply any.


Jim

Fran Crimi
07-20-2005, 06:05 PM
<blockquote><font class="small">Quote BigRigTom:</font><hr>
Fran at the risk of being a smart ass /ccboard/images/graemlins/cool.gif...If...
Positive squirt + Negative squirt = Zero squirt and you can achieve that why would you want to?
Aren't there other things that would be more beneficial to the advancement of skills and have a bigger cost/benefit ratio? /ccboard/images/graemlins/confused.gif <hr /></blockquote>

Good question, Tom. Gauging cb squirt is a big issue in ball pocketing. Even with the most sophisticated aiming systems, the player sill has to make adjustments for speed and distance, and there's always the potential for misjudging the adjustment, resulting in a missed shot.

Theoretically, if squirt could be minimized or canceled out when applying sidespin, the player would have to make less adjustments which would lead to better ball pocketing. That's pretty big and at least worth the effort of looking into.


Fran

Jal
07-21-2005, 05:42 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> Your theory is based on the assumption that every person who used the swipe method for the purpose of reducing cb squirt, in the history of the game, believed that they were striking the ball closer to center than they really were. I'm not saying you're wrong, but I'd rather wait for proof.

The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?...<hr /></blockquote>

Fran,

Yes, finally.

It turns out that this is a terrible way to apply english. To make a fair comparison with the standard method(s) we need to look at how much squirt is produced when the same spin/speed ratio is achieved by either one.

Let's call the tangent of the squirt angle when swiping across the center of the cueball TC, and the tangent of the squirt angle when hitting at the equivalent offset (to produce the same spin/speed ratio), TO.

The ratio TC/TO is equal to P/R where P is the distance of the cue's pivot point from the tip and R is the radius of the cueball (R=1.125). So if the pivot point is twelve inches (P=12), then the swiping method will produce over ten times as much squirt, in the opposite direction. And of course the comparison gets worse for lower squirt cues with greater pivot point distances.

You asked for proof but I'm not sure what you want. The math/physics is very simple and does not require any consideration of the details of the forces involved. Let me know if you need more info to be convinced.

Jim

Fran Crimi
07-21-2005, 08:50 AM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> Your theory is based on the assumption that every person who used the swipe method for the purpose of reducing cb squirt, in the history of the game, believed that they were striking the ball closer to center than they really were. I'm not saying you're wrong, but I'd rather wait for proof.

The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?...<hr /></blockquote>

Fran,

Yes, finally.

It turns out that this is a terrible way to apply english. To make a fair comparison with the standard method(s) we need to look at how much squirt is produced when the same spin/speed ratio is achieved by either one.

Let's call the tangent of the squirt angle when swiping across the center of the cueball TC, and the tangent of the squirt angle when hitting at the equivalent offset (to produce the same spin/speed ratio), TO.

The ratio TC/TO is equal to P/R where P is the distance of the cue's pivot point from the tip and R is the radius of the cueball (R=1.125). So if the pivot point is twelve inches (P=12), then the swiping method will produce over ten times as much squirt, in the opposite direction. And of course the comparison gets worse for lower squirt cues with greater pivot point distances.

You asked for proof but I'm not sure what you want. The math/physics is very simple and does not require any consideration of the details of the forces involved. Let me know if you need more info to be convinced.

Jim <hr /></blockquote>


OK. First, please forgive my simple language. I'm not a mathematician. I think it's understood that your term 'negative squirt' is really just a term to describe forward motion of the ball in the direction the cue stick is aimed. Correct? And it would make sense that the closer to the center you strike the cb, the less opportuinty there will be for positive squirt, thus more force in a straight line, or in this case, negative squirt.

So it would seem logical that the cue stick angle at impact would be an important variable in determining the amount of negative squirt relative to a particular shot.

The swiping method of applying sidespin is a big variable in itself. How much sidespin can you get?... which is why I would think it's important to be able to compare the amount of sidespin you get with that method as opposed to the parallel method and pivot methods.

I think that can only be measured by the action of the cb after the shot has been made. So that's another measurement that has yet to be addressed.

As for squirt, I sense that the swipe method is performed exclusively with topspin, thus making the arc of sidespin much smaller, over the top side of the cb. I also sense that the angle of the cue stick is much smaller at impact as opposed to the angle of the cue stick with the pivot method.

So, with the swipe method, it would seem to me that everything is much more contained, which is why it would seem the cb is traveling on a straighter line towards the point of contact on the ob, which again is why I think it's important to determine how much effective english you can obtain that way. Perhaps it's not much at all. We don't know.

Fran

Stretch
07-21-2005, 12:31 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> Your theory is based on the assumption that every person who used the swipe method for the purpose of reducing cb squirt, in the history of the game, believed that they were striking the ball closer to center than they really were. I'm not saying you're wrong, but I'd rather wait for proof.

The question that needs to be answered with proof is whether or not you can effectively apply english by striking the cb at or near center, with reduced squirt effect, and swiping across the side of the cb, somewhat like a horizontal version of the masse. Does anyone have the answer with proof?...<hr /></blockquote>

Fran,

Yes, finally.

It turns out that this is a terrible way to apply english. To make a fair comparison with the standard method(s) we need to look at how much squirt is produced when the same spin/speed ratio is achieved by either one.

Let's call the tangent of the squirt angle when swiping across the center of the cueball TC, and the tangent of the squirt angle when hitting at the equivalent offset (to produce the same spin/speed ratio), TO.

The ratio TC/TO is equal to P/R where P is the distance of the cue's pivot point from the tip and R is the radius of the cueball (R=1.125). So if the pivot point is twelve inches (P=12), then the swiping method will produce over ten times as much squirt, in the opposite direction. And of course the comparison gets worse for lower squirt cues with greater pivot point distances.

You asked for proof but I'm not sure what you want. The math/physics is very simple and does not require any consideration of the details of the forces involved. Let me know if you need more info to be convinced.

Jim <hr /></blockquote>


OK. First, please forgive my simple language. I'm not a mathematician. I think it's understood that your term 'negative squirt' is really just a term to describe forward motion of the ball in the direction the cue stick is aimed. Correct? And it would make sense that the closer to the center you strike the cb, the less opportuinty there will be for positive squirt, thus more force in a straight line, or in this case, negative squirt.

So it would seem logical that the cue stick angle at impact would be an important variable in determining the amount of negative squirt relative to a particular shot.

The swiping method of applying sidespin is a big variable in itself. How much sidespin can you get?... which is why I would think it's important to be able to compare the amount of sidespin you get with that method as opposed to the parallel method and pivot methods.

I think that can only be measured by the action of the cb after the shot has been made. So that's another measurement that has yet to be addressed.

As for squirt, I sense that the swipe method is performed exclusively with topspin, thus making the arc of sidespin much smaller, over the top side of the cb. I also sense that the angle of the cue stick is much smaller at impact as opposed to the angle of the cue stick with the pivot method.

So, with the swipe method, it would seem to me that everything is much more contained, which is why it would seem the cb is traveling on a straighter line towards the point of contact on the ob, which again is why I think it's important to determine how much effective english you can obtain that way. Perhaps it's not much at all. We don't know.

Fran

<hr /></blockquote>

Effective English, nice refference Fran. Also the idea that these methods have to be concidered against tangible results ie. just what is possible with the cue ball "after" the shot. I will swipe a ball if it's an easy foot longer close to a pocket or rail because i can get more effective spin going over the shorter distance that way to get the desired results off the first rail. I don't know how i do it. I'm sure back hand english is involved, but if i thought about it the shot wouldn't come out right. So i remain blissfully unaware. The other method of maximizing english or side of course is the draw drag which is always the better choice over distance. You can get all kinds of spin this way with as little as half a tip of sideing. You need some distance for this to work because it's a hard hit but the ob contact is soft. The backspin slows it down as it wares off, the hard side remains. Then when u touch the first rail it will jump off!

I also like to sqirt balls down where there's a slight angle as a way of getting max gear on the cue ball. You just line it up as a dead on and use the sideing to sqirt the cueball onto the proper contact.

Hope i didn't muddy the waters here with this post. St.

Jal
07-21-2005, 05:03 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr>.... I think it's understood that your term 'negative squirt' is really just a term to describe forward motion of the ball in the direction the cue stick is aimed. Correct? <hr /></blockquote>

Imagine a shot with right english. Normally the cueball will squirt over to the left of the line of the shot - the "line of the shot" being the line from the center of the cueball to the intended target. By "negative squirt" I mean having the cueball move to the right of this line instead of the left.


<blockquote><font class="small">Quote Fran Crimi:</font><hr> And it would make sense that the closer to the center you strike the cb, the less opportuinty there will be for positive squirt, thus more force in a straight line, or in this case, negative squirt.<hr /></blockquote>

Except for the negative squirt part (different meaning), I agree.

<blockquote><font class="small">Quote Fran Crimi:</font><hr>So it would seem logical that the cue stick angle at impact would be an important variable in determining the amount of negative squirt relative to a particular shot.

The swiping method of applying sidespin is a big variable in itself. How much sidespin can you get?... which is why I would think it's important to be able to compare the amount of sidespin you get with that method as opposed to the parallel method and pivot methods. <hr /></blockquote>

That's what I was trying to answer in the above post, at least for the case when you hit the cueball at the exact center while swiping across it at the same time. (Actually, for right english you would hit it a little left of center and end up a little right of center at the end of the contact period).

This method is rather inefficient at producing spin because of technical reasons concerning the amount of mass at the end of the stick the cueball "sees" when the stick is moving sideways. An analogy would be a glancing blow from a ping-pong ball, although that's a bit of an exaggeration I think.

But whether it's efficient or not doesn't matter when we compare the amount of squirt that's produced if we manage to get the same amount of spin on the ball in relation to the ball's forward speed (the spin/speed ratio). Simply put, swiping across the exact center of the cueball will result in vastly more squirt. It's kind of hard to explain why without the math, but it's simply the result of applying the sideways force. When you use the parallel method, you're not applying any sideways force except for that which develops as the tip rolls along the cueball as the cueball begins picking up spin. That's where the squirt comes from, but it is much smaller because this sideways force is much smaller.

<blockquote><font class="small">Quote Fran Crimi:</font><hr>I think that can only be measured by the action of the cb after the shot has been made. So that's another measurement that has yet to be addressed.<hr /></blockquote>

I don't trust any of these conclusions, even when I think the math is simple, such that I wouldn't like to have a table close at hand to try them out.

<blockquote><font class="small">Quote Fran Crimi:</font><hr>As for squirt, I sense that the swipe method is performed exclusively with topspin, thus making the arc of sidespin much smaller, over the top side of the cb. I also sense that the angle of the cue stick is much smaller at impact as opposed to the angle of the cue stick with the pivot method.

So, with the swipe method, it would seem to me that everything is much more contained, which is why it would seem the cb is traveling on a straighter line towards the point of contact on the ob, which again is why I think it's important to determine how much effective english you can obtain that way. Perhaps it's not much at all. We don't know.

Fran

<hr /></blockquote>

I'll kind of repeat what I said earlier in that when you're set up for parallel aiming and swoop across the contact point, in principle I think that you can reduce the amount of squirt. The smaller the offset the more effective this would be. However, perhaps a powerful flick of the wrist inward or outward by a player experienced at doing this, might get significant reduction at moderate to large offsets. Add to this your observation that players do it high on the ball, an interesting twist that should make it even more effective.

But I don't think it's useful to swipe when you're using backhand english. Unless you have the unlikely condition where the pivot point is forward of your bridge, you've already compensated for the squirt (maybe more than compensated) and this (the swoop) can only get you squirt in the other direction, with not much increase in spin, if any.

I hope this clarifies some things and that they're right. In the meantime I'll wash my mouth out for bringing up that negative squirt thing.

Jim

Fran Crimi
07-21-2005, 06:43 PM
OK. Thanks for taking the time to explain. I'll need some time to digest it all.

Fran

Fran Crimi
07-21-2005, 06:46 PM
Actually Stretch,

You're a breath of fresh air. LOL

I do relate to what you're saying, especially the I don't know why it happens part, and I'm starting to lean more and more towards your "I don't care that I don't know why" part. HAHAHAHAHA!

Fran

Jal
07-21-2005, 10:59 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> Actually Stretch,

You're a breath of fresh air. LOL

I do relate to what you're saying, especially the I don't know why it happens part, and I'm starting to lean more and more towards your "I don't care that I don't know why" part. HAHAHAHAHA!

Fran <hr /></blockquote>

Another satisfied customer. I'm sorry it's still not clear (my fault) but I didn't think I deserved that.

Jim

Fran Crimi
07-22-2005, 08:16 AM
Sorry about that JAL....I can see now how you may have thought I was referring to you, but it's not that way at all. You have been most helpful and considerate in addressing my questions and I'm appreciative of your patience with someone like me from the non-scientific community. Others with a scientific background aren't so patient, and as far as I'm concerned, it's their loss because just maybe they could stand to learn a few things from the instinctive, or for lack of a better word, sensory community of players in our group.

Just as I have seen people here become frustrated with those not able to grasp their scientific concepts, I too can become frustrated by those (not including yourself) who blatently refuse anything that can not be defined with a formula.

I can watch a student of mine shooting at the table, and then tell them exactly what was on their mind while they were shooting. I can tell them the thought process that led right up to their mistake. I can tell when someone is grabbing their cue too tightly, just by the sound, even on the softest stroke. There is no formula, no mathematical calculation for this.

And I can tell you that Earl Strickland swipes across that cue ball with a poise, grace and confidence at the table with a success rate that is incredible. So, do we believe the formulas, that swiping isn't the way to go, or has there yet been something undiscovered or left out by the scientific community that may surface 1, 2, or 5 years from now?

As for me, I've bent over backwards trying to show respect to our scientific community, however, I find their immediate dismissive responses to be unacceptable and frankly, quite pompus.

Perhaps those of us who don't play scientific pool should just keep our information to ourselves and let the scientific community discover it on their own, years down the road. That's what I'm feeling right now.

Fran

Fred Agnir
07-22-2005, 08:34 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> As for me, I've bent over backwards trying to show respect to our scientific community, however, I find their immediate dismissive responses to be unacceptable and frankly, quite pompus. <hr /></blockquote>Was there someone who dismissed anything you've brought up in this thread???

Fred

Stretch
07-22-2005, 08:53 AM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> Actually Stretch,

You're a breath of fresh air. LOL

I do relate to what you're saying, especially the I don't know why it happens part, and I'm starting to lean more and more towards your "I don't care that I don't know why" part. HAHAHAHAHA!

Fran <hr /></blockquote>

Another satisfied customer. I'm sorry it's still not clear (my fault) but I didn't think I deserved that.

Jim <hr /></blockquote>

Jim i'm 100% SURE Fran did not mean any malicious intent, and i'm sorry u took offence. If anything it was unfare of me to pose an over simplified version of things after your well thought out posts. St.~~sucks at math and physics but can shoot the eye out of a squirrel from 50 yards~~

Qtec
07-22-2005, 09:47 AM
[ QUOTE ]
Imagine a shot with right english. Normally the cueball will squirt over to the left of the line of the shot - the "line of the shot" being the line from the center of the cueball to the intended target. By "negative squirt" I mean having the cueball move to the right of this line instead of the left.

<hr /></blockquote>

Imagine the Qb as a clock. A straight shot [no E], the line of attack/force is thru 6 to 12. The line from the contact point thru the center of gravity of the Qb is the same. Thats why the Qb goes straight.
Using parallel aiming, if I was to give RE, lets say the point of contact would be 5. The line of force would be from 5 thru 1. The line thru the C of G would be 5 thru 11. Therefor the sqirt angle ie, the direction the ball takes,is somewhere inbetween.
Using BHE the line of force would be 5 thru 2, which would compensate for the sqirt and the ball would appear to go straight- but it doesnt. Not when you compare it to the angle of attack/force!
When swiping across the Qb, the angle of force is not the same as the original aiming direction. The tip must come from left to right. ie the angle of force could be 6 thru 2. The line thru the contact point and the Cof E is 6 thru 12. This means that the Qb will go to the right.
Its not positive squirt!
In the the cases of BHE and parallel , the tip follows the line of aim. In swiping, it doesnt.

Qtec

Jal
07-23-2005, 12:31 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> ....I can see now how you may have thought I was referring to you, but it's not that way at all. You have been most...<hr /></blockquote>

Thank you for the kind words Fran, and please pardon my ego. Believe me, I realize it's more of a chore to read some of this stuff than to write it, and I appreciate the courtesy you've shown me in bothering with it at all.

I'm a dabbler in physics. If you or anyone thinks that what I say is contrary to experience, I certainly take that seriously and will expect that I'm probably wrong. Given that you're an instructer, I have absolutely no doubt that you know infinitely more about the game than I do, and I'm sorry for your less than enriching encounters with us scientific types (or quasi-scientific types in my case).

Hopefully, in the end we'll find that there has been a lot more cross pollination than cross tempers generated by the interplay.

If you have serious doubts about anything I said and wish to continue discussing it, I'll shut up and maybe someone else will offer a fresh perspective.

Jim

Jal
07-23-2005, 12:59 AM
<blockquote><font class="small">Quote Stretch:</font><hr>

Jim i'm 100% SURE Fran did not mean any malicious intent, and i'm sorry u took offence. If anything it was unfare of me to pose an over simplified version of things after your well thought out posts. St.~~sucks at math and physics but can shoot the eye out of a squirrel from 50 yards~~

<hr /></blockquote>

Thank you Stretch. I didn't feel your post was at all inappropriate and appreciate the remarks about mine. While I'm not too sure about the swiping thing, for what it's worth I agreed with everything else you said.

Could you explain your method a little more? Do you set up for centerball and then swipe or are you already off to the side somewhat?

Jim

Fran Crimi
07-23-2005, 08:01 AM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> As for me, I've bent over backwards trying to show respect to our scientific community, however, I find their immediate dismissive responses to be unacceptable and frankly, quite pompus. <hr /></blockquote>Was there someone who dismissed anything you've brought up in this thread???

Fred <hr /></blockquote>

Here's a good one:

"Are there any instructors out there still teaching the "old-school" backhand "swoop" method of magical squirt reduction? I, personally, would not recommend this."

Well, hell. I need to go wake up those dead champions and let them know.

The other examples in this thread are more subtle, but it's there. I wasn't born yesterday.

Look at Jal's response to Stretch's description of what he does. Someone is actually asking questions about a technique without assuming or debunking. Great interaction and sharing of information.

Good thing you made it a point to specify "this thread." Then the list gets very, very long, as you well know.

Fran

dr_dave
07-23-2005, 09:52 AM
Fran,

I am sorry you took offense at what I wrote. I now very much regret that I wrote what I did. I should have learned my lesson by now that I should be extremely careful with what I write, but I guess I still have a lot to learn in the area of interpersonal communication. I could have expressed my opinion without offending others. Again, I am sorry I did not.

Having said that, I still think (this is just my opinion) that backhand swoop is too awkward and difficult to control to justify any possible advantages. And, after reading all messages here with my mind as open as possible, and putting all physics and equations aside, I still don't see any positives in the backhand swoop method (even though some people can apparently use it with success).

Regards,
Dave

PS: I hope you forgive me for my insensitive comments.

<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> As for me, I've bent over backwards trying to show respect to our scientific community, however, I find their immediate dismissive responses to be unacceptable and frankly, quite pompus. <hr /></blockquote>Was there someone who dismissed anything you've brought up in this thread???

Fred <hr /></blockquote>

Here's a good one:

"Are there any instructors out there still teaching the "old-school" backhand "swoop" method of magical squirt reduction? I, personally, would not recommend this."

Well, hell. I need to go wake up those dead champions and let them know.

The other examples in this thread are more subtle, but it's there. I wasn't born yesterday.

Look at Jal's response to Stretch's description of what he does. Someone is actually asking questions about a technique without assuming or debunking. Great interaction and sharing of information.

Good thing you made it a point to specify "this thread." Then the list gets very, very long, as you well know.

Fran
<hr /></blockquote>

Fran Crimi
07-23-2005, 11:08 AM
I know where you were coming from, Dave. I call it proof in a bubble. You guys all too often don't think out of the box.

There are cases of technology gone awry in our sport. Take the elbow drop debacle for instance. I'm positive now that it began as a miscommunication, where players, including myself were told not to "move" their elbow. The "move" part was meant for the backstroke, not the forward stroke.

Then the snowball started. It became don't drop your elbow. Then the tekkies arrived with proof in a bubble that supported this theory. I bought into it too, proof and all. Lots of us did. It then transposed into it being a really really bad thing to drop your elbow, because, see..."we have proof of the benefits of keeping your elbow still."

Yet, while all this was going on, the players still dropped their elbows, all over the world, in fact. But nobody seemed to notice. Eventually, some did start to notice and began to re-examine the logic and tunnel vision proof of this so-called bad and awful thing to do. Then another truth began to emerge; that more moving parts didn't necessarily constitute ineffeciency. On the contrary, when they're working together, they represent the epitome of efficiency.

Here's another good one. Shooting the cb up and down the length of the table will teach you speed control. Why do people think that works? They think it works because it provides a measurement; a measurement that is totally useless when you're pocketing a ball. If you want to learn how to feel speed control, then you should be pocketing balls.

As a scientist, how much time have you really devoted to exploring the swipe method? Have you sought out those who used it and questioned them? Have you spent any time at all practicing it yourself? Have you gone back in time to explore just how many people played that way and how successful they were? Do you know how many and which players play that way today?

No, I'm sure you haven't researched those things. Yet, your proof in a bubble is good enough for you.

Fran

Fred Agnir
07-23-2005, 11:21 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> . It became don't drop your elbow. Then the tekkies arrived with proof in a bubble that supported this theory. I bought into it too, proof and all. <hr /></blockquote>ALthough I agree with you, isn't it the "instructors" that have been advocating the "don't drop the elbow"? I'm a techie that has always advocated dropping the elbow (or at least see the legitimacy in it) because physiolocally, it makes sense. And I've also advocated for many years on this and every other board that more moving parts isn't necessarily less efficient. But, nobody on the instructor end (other than you, apparently) seem to want to listen to me.

Maybe you mean the "theory before practice" people? Maybe that's what you mean by "theory in a bubble." What I'm saying is that it's not the "scientist in the man" that your having issues with (on this particular subject). I think it's the man behind the science.

Fred

Fran Crimi
07-23-2005, 11:30 AM
<blockquote><font class="small">Quote Fred Agnir:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> . It became don't drop your elbow. Then the tekkies arrived with proof in a bubble that supported this theory. I bought into it too, proof and all. <hr /></blockquote>ALthough I agree with you, isn't it the "instructors" that have been advocating the "don't drop the elbow"? I'm a techie that has always advocated dropping the elbow (or at least see the legitimacy in it) because physiolocally, it makes sense. But, nobody on the instructor end (other than you, apparently) seem to want to listen to me.

Maybe you mean the "theory before practice" people? Maybe that's what you mean by "theory in a bubble."

Fred <hr /></blockquote>

Definitely, the instructors played a big role in that. It's my recollection that the scientific community as a whole supported it as well. You and I were among the few exceptions.

Fran

Fran Crimi
07-23-2005, 11:52 AM
I just thought of an example, Fred. I recall an older thread where Bob Jewett commented that a pro missed a shot in a tv match because he "dropped his elbow." I could probably locate the post if I took the time, but I remember getting the distinct impression that he clearly disagreed with the elbow drop at that time. I'm glad to see he's changed his mind since then.

Fran

Stretch
07-23-2005, 02:26 PM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Stretch:</font><hr>

Jim i'm 100% SURE Fran did not mean any malicious intent, and i'm sorry u took offence. If anything it was unfare of me to pose an over simplified version of things after your well thought out posts. St.~~sucks at math and physics but can shoot the eye out of a squirrel from 50 yards~~

<hr /></blockquote>

Thank you Stretch. I didn't feel your post was at all inappropriate and appreciate the remarks about mine. While I'm not too sure about the swiping thing, for what it's worth I agreed with everything else you said.

Could you explain your method a little more? Do you set up for centerball and then swipe or are you already off to the side somewhat?

Jim <hr /></blockquote>

Thanks Jim I'd be happy too. Although i can spin the rock well with accuracy it's been a loooooong process. It's so ingrained now that i stoped looking at it altogether because it is now simply muscle memory.

To answer your question. Yes i line up a swipe shot centre ball, or just a fraction in the direction of the spin.

To give you a picture imagine the swipe is really just a draw shot turned on it's side. You are never realy Parallel with the table top when drawing, there is always a slight elevation which means your tip is driveing down through the cue ball starting somewhere below the equator and finishing out through the other side and down from where it sits. Your tip is NOT pointing "at" the target it's pointing under it if the table were not there.

Turn everything on it's side and you'll see a swipe which is aimed at the target point but is exicuted from a point just to the left of centre (for left sideing) and finishes hooking left and away. Meanwhile the ball sqirts down the original centre ball aim line spinning like a top.

I absolutely do not trust swiping over distance. It's a short shot technique which is played softly for pocket wieght speed with max spin appropriate for where you want the CB to kick to off the first rail, or for spin induced throw shots, which have to be played softly for maximum effect.

When addressing the cue ball i'm aware of where my back hand is at contact. By timeing the back hand to be in the process of hooking in on contact or turning out, useing the bridge as a pivot, u can generate all the side i need with suprising accuracy (for a short shot).

For the longer ones like i said before the draw drag is the way to go. For this one i use the railway track aiming method. It helps to accurately parallel shift when your imaginary tracks are running down the edges of the cue ball. And it gives good feedback on how to hit the ball without jumping the tracks lol. Actualy the railway tracks imagery is excillent for all shots played with lots of side. Just send it spinning down the track. St.

PS Sorry for the long post...bet u don't ask me anything else. hehe

Jal
07-24-2005, 12:54 AM
<blockquote><font class="small">Quote Stretch:</font><hr> <blockquote><font class="small">Quote Jal:</font><hr>...
Could you explain your method a little more? Do you set up for centerball and then swipe or are you already off to the side somewhat?
<hr /></blockquote>
...
To answer your question. Yes i line up a swipe shot centre ball, or just a fraction in the direction of the spin.

To give you a picture imagine the swipe is really just a draw shot turned on it's side. You are never realy Parallel with the table top when drawing, there is always a slight elevation which means your tip is driveing down through the cue ball starting somewhere below the equator and finishing out through the other side and down from where it sits. Your tip is NOT pointing "at" the target it's pointing under it if the table were not there.

Turn everything on it's side and you'll see a swipe which is aimed at the target point but is exicuted from a point just to the left of centre (for left sideing) and finishes hooking left and away. Meanwhile the ball sqirts down the original centre ball aim line spinning like a top.<hr /></blockquote>

Your description of english as draw turned on its side was particularly interesting to me. Despite my somewhat lengthy discertations against swiping (more or less), your post reminded me that I tend to swipe downward on draw shots sometimes!

I think you'll agree that what your doing is 'dynamic' backhand english as has been defined earlier in this thread. I wonder if you've ever determined where the pivot point on your cue is located? The reason I ask is that I can see you not getting much (if any) net squirt if it's located near your bridge. But if it's far back of your bridge, as in two, three, or four or more times your bridge length, then squirt theory says that you should be seeing a lot of it?


<blockquote><font class="small">Quote Stretch:</font><hr>I absolutely do not trust swiping over distance. It's a short shot technique which is played softly for pocket wieght speed with max spin appropriate for where you want the CB to kick to off the first rail, or for spin induced throw shots, which have to be played softly for maximum effect.

When addressing the cue ball i'm aware of where my back hand is at contact. By timeing the back hand to be in the process of hooking in on contact or turning out, useing the bridge as a pivot, u can generate all the side i need with suprising accuracy (for a short shot).<hr /></blockquote>

You've obviously mastered this techique and I think I've seen pros do it too (Fran Crimi mentioned Earl Strickland). We all have our individualistic ways of doing things, and if they've been honed and perfected over years of playing, we quite justifiably take pride in them. But I wonder if you would recommend it to a player whose reached a certain skill level and what merits do you think it has over the static backhand version?

<blockquote><font class="small">Quote Stretch:</font><hr>For the longer ones like i said before the draw drag is the way to go. For this one i use the railway track aiming method. It helps to accurately parallel shift when your imaginary tracks are running down the edges of the cue ball. And it gives good feedback on how to hit the ball without jumping the tracks lol. Actualy the railway tracks imagery is excillent for all shots played with lots of side. Just send it spinning down the track. St.<hr /></blockquote>

From your mention of drag/draw here, I take it that you feel that dynamic BHE for shorter shots produces a larger spin to speed ratio than static BHE? I have to look at this more closely and try it out on a table. Here is a case though where I would tend to trust the physics more than my own perceptions, because it can be very hard to tell exactly where you're hitting the ball without some special setup. I do think you should get some increase, but would it be significant? Whatever the answer, I am sure that you can get more by moving out further on the cueball.

<blockquote><font class="small">Quote Stretch:</font><hr>PS Sorry for the long post...bet u don't ask me anything else. hehe<hr /></blockquote>
Au contraire, thanks for expanding on this and sorry for the delayed response.

Bob_Jewett
07-24-2005, 06:09 PM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> I just thought of an example, Fred. I recall an older thread where Bob Jewett commented that a pro missed a shot in a tv match because he "dropped his elbow." I could probably locate the post if I took the time, but I remember getting the distinct impression that he clearly disagreed with the elbow drop at that time. I'm glad to see he's changed his mind since then.

Fran <hr /></blockquote>
I don't think I ever wrote such a thing or at least I hope I didn't. Please track down the post.

What I did say is that Earl said that Nick van den Berg was unlikely to continue to play well if he didn't stop dropping his elbow. Nick drops his elbow pointlessly and lots more than the other pros I've noticed. I think Earl was right if not diplomatic.

Stretch
07-24-2005, 07:15 PM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote Stretch:</font><hr> <blockquote><font class="small">Quote Jal:</font><hr>...
Could you explain your method a little more? Do you set up for centerball and then swipe or are you already off to the side somewhat?
<hr /></blockquote>
...
To answer your question. Yes i line up a swipe shot centre ball, or just a fraction in the direction of the spin.

To give you a picture imagine the swipe is really just a draw shot turned on it's side. You are never realy Parallel with the table top when drawing, there is always a slight elevation which means your tip is driveing down through the cue ball starting somewhere below the equator and finishing out through the other side and down from where it sits. Your tip is NOT pointing "at" the target it's pointing under it if the table were not there.

Turn everything on it's side and you'll see a swipe which is aimed at the target point but is exicuted from a point just to the left of centre (for left sideing) and finishes hooking left and away. Meanwhile the ball sqirts down the original centre ball aim line spinning like a top.<hr /></blockquote>

Your description of english as draw turned on its side was particularly interesting to me. Despite my somewhat lengthy discertations against swiping (more or less), your post reminded me that I tend to swipe downward on draw shots sometimes!

I think you'll agree that what your doing is 'dynamic' backhand english as has been defined earlier in this thread. I wonder if you've ever determined where the pivot point on your cue is located? The reason I ask is that I can see you not getting much (if any) net squirt if it's located near your bridge. But if it's far back of your bridge, as in two, three, or four or more times your bridge length, then squirt theory says that you should be seeing a lot of it?


<blockquote><font class="small">Quote Stretch:</font><hr>I absolutely do not trust swiping over distance. It's a short shot technique which is played softly for pocket wieght speed with max spin appropriate for where you want the CB to kick to off the first rail, or for spin induced throw shots, which have to be played softly for maximum effect.

When addressing the cue ball i'm aware of where my back hand is at contact. By timeing the back hand to be in the process of hooking in on contact or turning out, useing the bridge as a pivot, u can generate all the side i need with suprising accuracy (for a short shot).<hr /></blockquote>

You've obviously mastered this techique and I think I've seen pros do it too (Fran Crimi mentioned Earl Strickland). We all have our individualistic ways of doing things, and if they've been honed and perfected over years of playing, we quite justifiably take pride in them. But I wonder if you would recommend it to a player whose reached a certain skill level and what merits do you think it has over the static backhand version?

<blockquote><font class="small">Quote Stretch:</font><hr>For the longer ones like i said before the draw drag is the way to go. For this one i use the railway track aiming method. It helps to accurately parallel shift when your imaginary tracks are running down the edges of the cue ball. And it gives good feedback on how to hit the ball without jumping the tracks lol. Actualy the railway tracks imagery is excillent for all shots played with lots of side. Just send it spinning down the track. St.<hr /></blockquote>

From your mention of drag/draw here, I take it that you feel that dynamic BHE for shorter shots produces a larger spin to speed ratio than static BHE? I have to look at this more closely and try it out on a table. Here is a case though where I would tend to trust the physics more than my own perceptions, because it can be very hard to tell exactly where you're hitting the ball without some special setup. I do think you should get some increase, but would it be significant? Whatever the answer, I am sure that you can get more by moving out further on the cueball.

<blockquote><font class="small">Quote Stretch:</font><hr>PS Sorry for the long post...bet u don't ask me anything else. hehe<hr /></blockquote>
Au contraire, thanks for expanding on this and sorry for the delayed response. <hr /></blockquote>

I cannot catagoricaly say that swipeing gives more spin to speed ratio over a short distance. What i CAN say is that the dynamic action of applying said spin gives me a better "feel" for the shot over the static SPFF version.....in this instance. I'll use an analogy to explain this one. Your playing tennis and your 10 feet from the net and recieveing a screaming forhand. In a flash you think "drop shot". You cut the ball with a sliceing motion with perfect wieght to just clear the net and die on the first bounce. So many things have to happen perfectly that unless you proceed with "dynamic" action, it aint going to happen. Swipeing is like playing a drop shot. You practice this specialty stroke and recognize the specific conditions where it is an "option". If everything says yes, you just do it.

I would NOT recomend swipeing to novis players, simply because i consider these and other specific shots to be of little overall advantage to them. Developeing players are better served by honeing shots and strategies that have more wide rangeing applications. Walk before you can run!

When you become proficiant at running runnable tables, and competing at a consistantly high level, then it is time to experiment with these technichs to tip the balance in your favour. But here again it's personal choice. St.

Rod
07-24-2005, 11:54 PM
Your a brave woman Fran, very brave. When I read some of these posts, I get the feeling their trying to re-invent the wheel. However now their telling you the tire composition and tread pattern and in theory why it should work.

People, get sold or sell themselves on various aspects of pool or anything imaginable. Its nothing new but because it works for them or is the current rage doesn't make it right for everyone.

We all see things just a little different, to say the least. I think those that keeps it easy to understand advance to the head of the class. We surely don't want someone scratching their head wondering what we just said.

[ QUOTE ]
I can watch a student of mine shooting at the table, and then tell them exactly what was on their mind while they were shooting. I can tell them the thought process that led right up to their mistake. <hr /></blockquote>

It is interesting and I do the same. Of course its not a 100 percent but it is very high. Seeing how people react in situations is just priceless. To me that is a very important part of any game or life. Watching peoples reactions is huge and I feel just as important.

As an example the last womens team I coached going to Vegas took second. Our last night together had little to do with playing pool. I told them (not the first time but more indepth) how to conduct themselves playing a game of pool. BTW, they won next year and Madelyn won the singles. I was a proud papa. I raised my girls right. LOL

Rod

Fran Crimi
07-25-2005, 12:02 AM
This is the only remotely related post I could find by you in this forum, and it's definitely not the one I read.
not the post (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=176891&amp;Foru m=All_Forums&amp;Words=Bob_Jewett&amp;Match=Username&amp;Searc hpage=9&amp;Limit=25&amp;Old=allposts&amp;Main=175507&amp;Search=t rue#Post176891)

Even by the wildest stretch of the imagination, there's no way I could have recalled what I did by reading this post. It must have been somewhere else.

I won't dispute with you what you claim you said. You know what you did or didn't say better than anyone else. It's best I just retract my comment.

I also remember reading an article of yours on the elbow and putting it down half-way through thinking what a negative spin it was putting on the elbow-drop. I don't even remember what you wrote, Bob. You may have been simply pointing out the pitfalls of excessive and unnecessary use. Nonetheless, I remember the focus being more on the negative end.

Players here and there occasionally overuse the elbow drop to the point of detriment, and yes, that's a danger, but we've been through the last 30 years of NEVER DROP YOUR ELBOW, and finally, we're on the brink of breaking through where some people are starting to see that it's not a terrible evil thing to do.

And what do we do? We make sure to remind them of the pitfalls.

I don't expect you to agree, Bob, but timing is everything. I know...timing isn't science. Facts are facts, right?

Fran

Fran Crimi
07-25-2005, 12:43 AM
<blockquote><font class="small">Quote Rod:</font><hr> Your a brave woman Fran, very brave.
Rod
<hr /></blockquote>

Do me a favor Rod...just stick around long enough to punch me an air hole when they pound that final nail into my coffin. /ccboard/images/graemlins/grin.gif

Hey, nice story about the team. Heartwarming.

Fran

Stretch
07-25-2005, 06:44 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote Rod:</font><hr> Your a brave woman Fran, very brave.
Rod
<hr /></blockquote>



Do me a favor Rod...just stick around long enough to punch me an air hole when they pound that final nail into my coffin. /ccboard/images/graemlins/grin.gif

Knowbody's going to be doing any nailing as long as i'm still standing Sis. St.

Bob_Jewett
07-25-2005, 10:12 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> ...
I won't dispute with you what you claim you said. You know what you did or didn't say better than anyone else. ... <hr /></blockquote>
One of the things I said was that nearly every top pro drops his/her elbow on all power shots. Or at least that's what I've observed in the players I've seen. One of the points I made in the articles I wrote about elbow drop in BD is that timing is very important.

Fran Crimi
07-25-2005, 11:02 AM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> <blockquote><font class="small">Quote Fran Crimi:</font><hr> ...
I won't dispute with you what you claim you said. You know what you did or didn't say better than anyone else. ... <hr /></blockquote>
One of the things I said was that nearly every top pro drops his/her elbow on all power shots. Or at least that's what I've observed in the players I've seen. One of the points I made in the articles I wrote about elbow drop in BD is that timing is very important. <hr /></blockquote>

Yes, but unfortunately those important points become practically moot because you neglected to consider the most important fact of all; and that is that there is a massive population of readers out there who are frightened to death to even attempt a try at an elbow drop for fear they'll burn in pool hell, thanks to decades of public debunking.

How do you think those people would view your comments? Do you think they would focus on the positive or the negative?

I know that people like yourself in the scientific community take pride in your objectivity, but if you put everything on a scale right now, including public perception, the weight tips drastically towards "it's a bad thing to drop your elbow, so don't even try it."

The one thing we don't want to do is make people afraid to try something and experiment on their own. I see that they're already afraid to try certain things and I think that both instructors and scientists, of which you are both, need to be more conscious about not fueling that fear.

And if it takes a little affirmative action along the way to cancel out decades of fear-based skepticism, then let's do it.

Fran

SpiderMan
07-27-2005, 06:04 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> There are cases of technology gone awry in our sport. Take the elbow drop debacle for instance. I'm positive now that it began as a miscommunication, where players, including myself were told not to "move" their elbow. The "move" part was meant for the backstroke, not the forward stroke.

Then the snowball started. It became don't drop your elbow. Then the tekkies arrived with proof in a bubble that supported this theory. I bought into it too, proof and all. Lots of us did. It then transposed into it being a really really bad thing to drop your elbow, because, see..."we have proof of the benefits of keeping your elbow still."
Fran <hr /></blockquote>

Hey Fran,

Are you making a "bubble" generalization, similar to what you've accused "us" of?

I don't recall Dave's particular stance, but several of us "techies" (Fred and I in particular) seem to believe that the "elbow drop" is a natural extension of the follow-through. I'd say the biggest proponent of "pinned elbow, don't move it at all", is RandyG, and he's not a "techie".

SpiderMan

Fran Crimi
07-27-2005, 07:16 AM
<blockquote><font class="small">Quote SpiderMan:</font><hr>
Hey Fran,

Are you making a "bubble" generalization, similar to what you've accused "us" of?

I don't recall Dave's particular stance, but several of us "techies" (Fred and I in particular) seem to believe that the "elbow drop" is a natural extension of the follow-through. I'd say the biggest proponent of "pinned elbow, don't move it at all", is RandyG, and he's not a "techie".

SpiderMan <hr /></blockquote>

See...again, you're not thinking out of the box. This isn't about recent developments. It's about 30 years of history. You obviously weren't around, because if you were, you'd know that over the course of history, Randy was not the biggest proponent of the rigid elbow. Everyone was, all at the same time, all together. It went undisputed, except for Phil Capelle, who everyone thought was nuts, until recently.

Please don't challenge me about something you weren't even around to witness.

Edited portion:
The elbow-drop story I posted was written as an EXAMPLE of how things can go wrong. You and Fred joining the technical community does not indicate the beginning of the technical community. It existed long before that.

My point is simply don't be so quick to debunk something just because the formulas don't add up or because something doesn't seem to make logical sense to you at this particular point in time. You could be wrong.

SpiderMan
07-27-2005, 08:09 AM
<blockquote><font class="small">Quote Fran Crimi:</font><hr> <blockquote><font class="small">Quote SpiderMan:</font><hr>
Hey Fran,

Are you making a "bubble" generalization, similar to what you've accused "us" of?

I don't recall Dave's particular stance, but several of us "techies" (Fred and I in particular) seem to believe that the "elbow drop" is a natural extension of the follow-through. I'd say the biggest proponent of "pinned elbow, don't move it at all", is RandyG, and he's not a "techie".

SpiderMan <hr /></blockquote>

See...again, you're not thinking out of the box. This isn't about recent developments. It's about 30 years of history. You obviously weren't around, because if you were, you'd know that over the course of history, Randy was not the biggest proponent of the rigid elbow. Everyone was, all at the same time, all together. It went undisputed, except for Phil Capelle, who everyone thought was nuts, until recently.

Please don't challenge me about something you weren't even around to witness.

Fran <hr /></blockquote>


No thanks, I'll stand by what I said. It's today's "techies", and this community in particular, that you insult with your generalizations. Diverting focus to someone else's stance on issues thirty years ago doesn't change that.

"In" or "out" of the box is meaningless without follow-through. Scientific method isn't stirring the pot and tossing out questions. It's about actually working for explanations, and being willing to accept results whether or not they back up your personal agenda.

SpiderMan

Fran Crimi
07-27-2005, 08:10 AM
I had edited my post, probably while you were responding.

Fran Crimi
07-27-2005, 09:33 AM
<blockquote><font class="small">Quote SpiderMan:</font><hr>

No thanks, I'll stand by what I said. It's today's "techies", and this community in particular, that you insult with your generalizations. Diverting focus to someone else's stance on issues thirty years ago doesn't change that.

"In" or "out" of the box is meaningless without follow-through. Scientific method isn't stirring the pot and tossing out questions. It's about actually working for explanations, and being willing to accept results whether or not they back up your personal agenda.

SpiderMan <hr /></blockquote>

Because of your technical knowledge, you guys are in a position of authority. With that authority comes responsibility. That responsibility should include an examination of whether you have factored in all of the relevant variables. If you can't factor in all of those variables, or if you sense that there may be additional unknowns, then your conclusion must be stated as limited or conditional.

That's not happening here nearly enough. Presenting your discoveries or opinions in a responsible way is critical, otherwise you may simply be repeating history. It is your responsibility to inform the public of the limitations of your conclusions. It shouldn't have to be ours to point out all the obvious and potential variables that you missed. You should know better, and if you find that insulting, then go ahead and be insulted.

Fran

Voodoo Daddy
07-27-2005, 10:51 AM
4 Pages of BLAH BLAH...puke inducing. Maybe we should all move to Texas, seems like thats the only place on the planet where any pool knowledge is... /ccboard/images/graemlins/smirk.gif!!