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Bob_Jewett
09-18-2007, 01:04 PM
With the present understanding of throw, it's clear that for thin cut shots -- say around 45 degrees -- inside english will amazingly decrease the throw because the higher speed of rubbing leads to a lower coefficient of friction and therefor less sideways force. So it occurred to me that for such a cut shot, you might want to use a little bit of outside english (right side spin for a cut to the left) and no draw or follow to achieve maximum throw.

Has this been noted before? Does it seem correct?

Deeman3
09-18-2007, 01:37 PM
It seems correct to me but it may be as much a case of reducing CIT in the opposite direction than the actual added throw value toward the pocket/target.

What do you think?

SKennedy
09-18-2007, 01:42 PM
You guys have got to start speaking English (and I don't mean spin)!

dr_dave
09-18-2007, 02:32 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> With the present understanding of throw, it's clear that for thin cut shots -- say around 45 degrees -- inside english will amazingly decrease the throw because the higher speed of rubbing leads to a lower coefficient of friction and therefor less sideways force. So it occurred to me that for such a cut shot, you might want to use a little bit of outside english (right side spin for a cut to the left) and no draw or follow to achieve maximum throw.

Has this been noted before? Does it seem correct? <hr /></blockquote>Bob,

You can see this effect in Diagram 1 of my February '07 article (http://billiards.colostate.edu/bd_articles/2007/feb07.pdf). In TP A.28 (http://billiards.colostate.edu/technical_proofs/new/TP_A-28.pdf), I have plots that show every throw effect and trend for a wide variety of speeds and types and amount of English. Also, your conclusion above, along with many more summary statements about throw are included in my June '07 throw summary article (http://billiards.colostate.edu/bd_articles/2007/june07.pdf). The complete list didn't make it into the print edition due to size constraints, but the list is in the online version of the article.

Regards,
Dave

dr_dave
09-18-2007, 02:37 PM
<blockquote><font class="small">Quote Deeman3:</font><hr> It seems correct to me but it may be as much a case of reducing CIT in the opposite direction than the actual added throw value toward the pocket/target.

What do you think? <hr /></blockquote>Spin-induced throw (SIT) and collision-induced throw (CIT) are not two independent things that add. The amount of throw (it would be called CIT in this case) changes with the relative speed between the ball surfaces. See my previous posting on this topic (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=172771&amp;page =&amp;view=&amp;sb=&amp;o=&amp;vc=1) for more details.

Regards,
Dave

dr_dave
09-18-2007, 02:44 PM
<blockquote><font class="small">Quote SKennedy:</font><hr> You guys have got to start speaking English (and I don't mean spin)!<hr /></blockquote>There is a lot of terminology and phrases dealing with throw. My June '07 article (http://billiards.colostate.edu/bd_articles/2007/june07.pdf) defines most of the important terms. A more complete glossary of terms and phrases can be found in my online glossary (http://billiards.colostate.edu/resources/glossary.pdf).

I think throw is one of the most complicated and least understood things in the pool world. That's why I wrote a series of twelve articles on the topic (see my August '06 through July '07 articles (http://billiards.colostate.edu/bd_articles/index.html)).

Many throw topics have also been discussed at great length on this forum. Many of the highlights can be found under "throw" here (http://billiards.colostate.edu/threads.html).

Happy reading,
Dave

wolfdancer
09-18-2007, 02:46 PM
Dr. Dave, I have your latest DVD on hi speed photography. Have been dealing with software/computer problems, and haven't had the time to sit back and enjoy the show...now I'm off on another short golfing trip...but hope to post a little feedback here about the DVD, when i return. It sounds like it's going to be enjoyable to view....

dr_dave
09-18-2007, 02:49 PM
<blockquote><font class="small">Quote wolfdancer:</font><hr> Dr. Dave, I have your latest DVD on hi speed photography. Have been dealing with software/computer problems, and haven't had the time to sit back and enjoy the show...now I'm off on another short golfing trip...but hope to post a little feedback here about the DVD, when i return. It sounds like it's going to be enjoyable to view.... <hr /></blockquote>
Wolfie,

This is kind of off-topic for this thread, but I hope you enjoy it and let me know what you think.

Regards,
Dave

Deeman3
09-18-2007, 03:34 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Deeman3:</font><hr> It seems correct to me but it may be as much a case of reducing CIT in the opposite direction than the actual added throw value toward the pocket/target.

What do you think? <hr /></blockquote>Spin-induced throw (SIT) and collision-induced throw (CIT) are not two independent things that add. The amount of throw (it would be called CIT in this case) changes with the relative speed between the ball surfaces. See my previous posting on this topic (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=172771&amp;page =&amp;view=&amp;sb=&amp;o=&amp;vc=1) for more details.

Regards,
Dave <hr /></blockquote>

<font color="blue">So Dave, are you saying that the outside does not diminish the CIT. I do understand your point of the balls not caring if it is CIT or SIT, but I still believe, perhaps falsely, that the cue ball with velocity in the direction of the cut introduces CIT and that the adding of inside would add more SIT and the adding of outside would cancel at least some of the throw resulting from the CIT. Otherwise, it would seem i would not need a hint of outside to avoid the occasional cling that shows up when munching Freedom Fries between shots. /ccboard/images/graemlins/cool.gifIs that incorrect?

For this to be not true, would the forward speed of the cue ball not have to be zero? Not being a technical guy, I might be overlooking some important physics point such as the point of the observer in "seeing" velocity. I just can't seem to make my mind think in those small terms. /ccboard/images/graemlins/tongue.gif /ccboard/images/graemlins/frown.gif

Is it possible that the spining of the cue ball due to applied english, makes the forward motion moot?</font color>

okinawa77
09-18-2007, 03:52 PM
Bob,

I have noted this, in my head. I use outside english quite often, mostly in straight pool. It also helps after pocketing the ball, the cue ball with outside english will hit a rail and accellerate off....which helps with the secondary breaks.

This can be used to another advantage...if you have an object ball near the foot corner pocket and you shoot the 45 degree angle cut shot using low outside english, you are effectively giving the sending the object ball with simulated natural roll to the pocket.

It's kind of like pissing with the wind to your back, rather than pissing into the wind.

dr_dave
09-18-2007, 04:22 PM
Deeman,

Here's a pertinent quote from my squirt, swerve, and throw thread (http://www.billiardsdigest.com/ccboard/showthreaded.php?Cat=&amp;Board=ccb&amp;Number=256685&amp;page =0&amp;view=collapsed&amp;sb=5&amp;o=&amp;fpart=1):
<blockquote><font class="small">Quote dr_dave:</font><hr>Throw direction depends on the direction of the relative motion of the surface of the cue ball in contact with the object ball. This direction is affected by both cut angle and spin. I think my January '07 (http://billiards.colostate.edu/bd_articles/2007/jan07.pdf) and February '07 (http://billiards.colostate.edu/bd_articles/2007/feb07.pdf) articles illustrate the different possibilities quite well.
...
Object ball throw depends on cut angle, shot speed, type and amount of English, and the amount of vertical plane spin (draw, follow, stun). My series of twelve articles on throw (http://billiards.colostate.edu/bd_articles/index.html) elaborate on all of these factors. Collision-induced throw (CIT) and spin-induced throw (SIT) are just different names for throw, depending upon the primary cause of the throw, but the effects don't really combine as separate factors.<hr /></blockquote>
I'll try to give simple answers below, but I think the illustrations and examples in the articles do a much better job at answering the questions.
<blockquote><font class="small">Quote Deeman3:</font><hr>So Dave, are you saying that the outside does not diminish the CIT.<hr /></blockquote>Outside English (OE) can diminish, eliminate, or even reverse the direction of throw. But at larger cut angles, a small amount of OE can actually increase the amount of throw (e.g., see Diagram 1 in my February '07 article (http://billiards.colostate.edu/bd_articles/2007/feb07.pdf)). Again, the reason has to do with the relative surface speed between the balls. Sliding friction (and therefore throw) is greater at slower relative surface speeds.

<blockquote><font class="small">Quote Deeman3:</font><hr>I do understand your point of the balls not caring if it is CIT or SIT, but I still believe, perhaps falsely, that the cue ball with velocity in the direction of the cut introduces CIT and that the adding of inside would add more SIT<hr /></blockquote>Again, CIT and SIT are not separate effects that add. With larger cut angles, inside English (IE) increases the relative surface speed between the balls and reduces the amount of friction and the amount of throw (see the same diagram).

<blockquote><font class="small">Quote Deeman3:</font><hr>and the adding of outside would cancel at least some of the throw resulting from the CIT.<hr /></blockquote>For a large cut angle, a small amount of OE can reduce (but not reverse) the surface speed some resulting in more friction and more throw.

<blockquote><font class="small">Quote Deeman3:</font><hr>Otherwise, it would seem i would not need a hint of outside to avoid the occasional cling that shows up when munching Freedom Fries between shots. /ccboard/images/graemlins/cool.gifIs that incorrect?<hr /></blockquote>Gearing OE (see my January '07 article (http://billiards.colostate.edu/bd_articles/2007/jan07.pdf)) completely eliminates throw and cling, regardless of how many fries you eat between shots. It's just tough judging the exact "gearing" amount of OE you need for each cut angle.

I hope the illustrations, graphs, and examples in the articles help. I think they will certainly help more than me trying to write more here.

Regards,
Dave

cushioncrawler
09-18-2007, 05:15 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> With the present understanding of throw, it's clear that for thin cut shots -- say around 45 degrees -- inside english will amazingly decrease the throw because the higher speed of rubbing leads to a lower coefficient of friction and therefor less sideways force. So it occurred to me that for such a cut shot, you might want to use a little bit of outside english (right side spin for a cut to the left) and no draw or follow to achieve maximum throw. Has this been noted before? Does it seem correct?<hr /></blockquote>Bob -- This haz been mentioned a few times. It might have been me that once said that throw would be maximized if/when the ball'to'ball sliding endz (drops to zero) at the instant that the ballz part company. Hencely, az u said, a bit of OE might give more throw than lots of OE.

The same applyz to cushion rebound. Last night, in my league match, i missed a shot where i wanted the qball to come off the cushion squarer, to get a cannon, but i put so much check side on the qball that i got little "squaring up", and i missed (duzzenmadder, i still won by a mile).

But, getting back to that 45dg cutshot, i am wondering why u/me would want to (need to) minimize any throw for what iz really an eezy thickish cut (ie not a 1/16th sort of very thin cut). But i am thinking that such knowledge would be handy where one needz OE or IE for (qball) pozitional reasons.

And, for sure i need to aim for a thickish contact on the red to pot the red (English billiards on a 12' table) when i am rolling the qball, and, a thinnish contact when i am stunning the shot.

And, when i am "slamming" the red into a top pocket, to take the qball around the table and back to the "spot end" for good pozzy, i havta aim very thickish on the red, even tho it iz uzually still a stun-shot. madMac.

cushioncrawler
09-18-2007, 05:30 PM
<blockquote><font class="small">Quote okinawa77:</font><hr>..... It's kind of like pissing with the wind to your back, rather than pissing into the wind.<hr /></blockquote>This remindz me of the time i had a pee on top of hill on a very very windy day. I had my back to the wind, the weewee went down to allmost grass level, then arked upwards and backwards to within inches of my face, then arked away from my face and ended up exiting horizontally. No hang-gliding that day. madMac.

cushioncrawler
09-18-2007, 05:39 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>.....Gearing OE.... completely eliminates throw and cling, regardless of how many fries you eat between shots....<hr /></blockquote>Dr Dave -- Us old "English billiards" playerz could point out that this might be so for the OB trajektory, but cling (kicks) still affekt the trajektory of the qball (which iz of utmost importance to billiards), ie kicks allwayz affekt the deflexion angle (for a rolling qball at least).

Kum to think of it, cling will (can) often shorten the roll distance for an OB allso. So, the rule (for pool) might be -- "uze gearing OE, plus some extra pace". madMac.

pooltchr
09-18-2007, 05:54 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> Outside English (OE) can diminish, eliminate, or even reverse the direction of throw.
Regards,
Dave <hr /></blockquote>

Dave,
Are you saying that OE on the cue ball can cause the OB to move off the line of centers at contact to the opposite direction from that which the cue ball was traveling at contact?

Steve

Deeman3
09-19-2007, 07:10 AM
Thanks Dave. I'll have to take a Vicodin or two before I go through the twelve articles but very much appreciate the answers. I think we pretty much agree or otherwise, I missed that ball last night! /ccboard/images/graemlins/grin.gif

SKennedy
09-19-2007, 08:16 AM
My comment was tongue-in-cheek, but I usually end up foot-in-mouth! While I do know "throw," I did not know what CIT stood for, etc. Thanks for the info., the work you do, and providing info to others for a better understanding of the game.

dr_dave
09-19-2007, 08:46 AM
<blockquote><font class="small">Quote cushioncrawler:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>.....Gearing OE.... completely eliminates throw and cling, regardless of how many fries you eat between shots....<hr /></blockquote>Dr Dave -- Us old "English billiards" playerz could point out that this might be so for the OB trajektory, but cling (kicks) still affekt the trajektory of the qball (which iz of utmost importance to billiards), ie kicks allwayz affekt the deflexion angle (for a rolling qball at least).

Kum to think of it, cling will (can) often shorten the roll distance for an OB allso. So, the rule (for pool) might be -- "uze gearing OE, plus some extra pace". madMac. <hr /></blockquote>Mac,

Here's the definition of "cling" from my online glossary (http://billiards.colostate.edu/resources/glossary.pdf):

cling: excessive friction and throw caused by non-ideal surface conditions at the point of contact between two balls (e.g., a chalk smudge).

Based on this definition, cling has no effect on a shot with gearing outside English. Also from the glossary:

gearing outside English: the amount of outside English that results in no sliding between the cue ball and object ball during contact. Instead, during contact, the CB rolls on the OB like two meshing gears. The result is no throw.

How do you define "cling" and "gearing outside English," and why do you think the CB's or OB's motion will be affected by increased friction if there is no sliding?

Regards,
Dave

dr_dave
09-19-2007, 08:51 AM
<blockquote><font class="small">Quote pooltchr:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr> Outside English (OE) can diminish, eliminate, or even reverse the direction of throw.<hr /></blockquote>Dave,
Are you saying that OE on the cue ball can cause the OB to move off the line of centers at contact to the opposite direction from that which the cue ball was traveling at contact?<hr /></blockquote>Absolutely. Throw direction depends on the direction of motion of the CB's surface relative to the OB's surface at the point of contact. With "gearing OE" there is no relative motion and no throw. With less than gearing OE, the throw is one direction; and with more than gearing OE, the throw is in the other direction. My January '07 article (http://billiards.colostate.edu/bd_articles/2007/jan07.pdf) has illustrations, explanations, and examples to explain all of this. Check it out.

Regards,
Dave

dr_dave
09-19-2007, 09:03 AM
<blockquote><font class="small">Quote Deeman3:</font><hr> Thanks Dave. I'll have to take a Vicodin or two before I go through the twelve articles but very much appreciate the answers. I think we pretty much agree or otherwise, I missed that ball last night! /ccboard/images/graemlins/grin.gif<hr /></blockquote>It took me a year to do all of the work for those twelve articles, so you're not getting much sympathy from me for how much work it will be for you to do a little reading. The articles are even full of illustrations, examples, and video references to help make the reading easier. Give me a break. /ccboard/images/graemlins/confused.gif

If you really want to feel some pain, try to work through the math and physics at TP A.14 (http://billiards.colostate.edu/technical_proofs/new/TP_A-14.pdf). That's the real source (along with the experiments I did) of all of the articles, plots, and knowledge statements about throw.

Happy reading,
Dave

PS: Try washing down that Vicodin with some JD. It helps prevent cling of the pill in your throwt (sometimes it is fun to spell like Mac). /ccboard/images/graemlins/wink.gif

dr_dave
09-19-2007, 09:05 AM
<blockquote><font class="small">Quote SKennedy:</font><hr> My comment was tongue-in-cheek, but I usually end up foot-in-mouth! While I do know "throw," I did not know what CIT stood for, etc. Thanks for the info., the work you do, and providing info to others for a better understanding of the game. <hr /></blockquote>You're welcome, and thank you.

Regards,
Dave

Deeman3
09-19-2007, 10:26 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Deeman3:</font><hr> Thanks Dave. I'll have to take a Vicodin or two before I go through the twelve articles but very much appreciate the answers. I think we pretty much agree or otherwise, I missed that ball last night! /ccboard/images/graemlins/grin.gif<hr /></blockquote>It took me a year to do all of the work for those twelve articles, so you're not getting much sympathy from me for how much work it will be for you to do a little reading. The articles are even full of illustrations, examples, and video references to help make the reading easier. Give me a break. /ccboard/images/graemlins/confused.gif

If you really want to feel some pain, try to work through the math and physics at TP A.14 (http://billiards.colostate.edu/technical_proofs/new/TP_A-14.pdf). That's the real source (along with the experiments I did) of all of the articles, plots, and knowledge statements about throw.

Happy reading,
Dave

PS: Try washing down that Vicodin with some JD. It helps prevent cling of the pill in your throwt (sometimes it is fun to spell like Mac). /ccboard/images/graemlins/wink.gif <hr /></blockquote>

<font color="blue"> Dave,

If I wanted to do all that research I'd get me a big bottle of JD and film porno instead. I'd rather kick back and benefit from the hard work you guys do and act as if i knew it all along when the question comes up. It's a non-scientist sort of thing.

Thanks for the advice on the Vicoden, it did work and, now, I really don't careasmuchabouthesituationwewerediscus....;ohfnpoi qnb;ljebr

Ah! Donuts!!! /ccboard/images/graemlins/smirk.gif </font color>

dr_dave
09-19-2007, 10:34 AM
<blockquote><font class="small">Quote Deeman3:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote Deeman3:</font><hr> Thanks Dave. I'll have to take a Vicodin or two before I go through the twelve articles but very much appreciate the answers. I think we pretty much agree or otherwise, I missed that ball last night! /ccboard/images/graemlins/grin.gif<hr /></blockquote>It took me a year to do all of the work for those twelve articles, so you're not getting much sympathy from me for how much work it will be for you to do a little reading. The articles are even full of illustrations, examples, and video references to help make the reading easier. Give me a break. /ccboard/images/graemlins/confused.gif

If you really want to feel some pain, try to work through the math and physics at TP A.14 (http://billiards.colostate.edu/technical_proofs/new/TP_A-14.pdf). That's the real source (along with the experiments I did) of all of the articles, plots, and knowledge statements about throw.

Happy reading,
Dave

PS: Try washing down that Vicodin with some JD. It helps prevent cling of the pill in your throwt (sometimes it is fun to spell like Mac). /ccboard/images/graemlins/wink.gif <hr /></blockquote>

<font color="blue"> Dave,

If I wanted to do all that research I'd get me a big bottle of JD and film porno instead. I'd rather kick back and benefit from the hard work you guys do and act as if i knew it all along when the question comes up. It's a non-scientist sort of thing.

Thanks for the advice on the Vicoden, it did work and, now, I really don't careasmuchabouthesituationwewerediscus....;ohfnpoi qnb;ljebr

Ah! Donuts!!! /ccboard/images/graemlins/smirk.gif </font color> <hr /></blockquote>Deeman,

/ccboard/images/graemlins/grin.gif /ccboard/images/graemlins/grin.gif /ccboard/images/graemlins/grin.gif

I think you are the best poster in the history of the CCB. You have a great combination of humility, arrogance, humor, smart-assed-ness, southern hospitality, in-your-face-ness, and writing-style flair. You also seem to have lots of good knowledge and experience.

If you were here, I would want to give you a big hug (in a manly sort of way) to thank you for continuing to share with us.

Regards,
Dave

Jal
09-19-2007, 12:27 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote cushioncrawler:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>.....Gearing OE.... completely eliminates throw and cling, regardless of how many fries you eat between shots....<hr /></blockquote>Dr Dave -- Us old "English billiards" playerz could point out that this might be so for the OB trajektory, but cling (kicks) still affekt the trajektory of the qball (which iz of utmost importance to billiards), ie kicks allwayz affekt the deflexion angle (for a rolling qball at least).

Kum to think of it, cling will (can) often shorten the roll distance for an OB allso. So, the rule (for pool) might be -- "uze gearing OE, plus some extra pace". madMac. <hr /></blockquote>Mac,

Here's the definition of "cling" from my online glossary (http://billiards.colostate.edu/resources/glossary.pdf):

cling: excessive friction and throw caused by non-ideal surface conditions at the point of contact between two balls (e.g., a chalk smudge).

Based on this definition, cling has no effect on a shot with gearing outside English. Also from the glossary:

gearing outside English: the amount of outside English that results in no sliding between the cue ball and object ball during contact. Instead, during contact, the CB rolls on the OB like two meshing gears. The result is no throw.

How do you define "cling" and "gearing outside English," and why do you think the CB's or OB's motion will be affected by increased friction if there is no sliding?

Regards,
Dave <hr /></blockquote>I think maybe you missed his semi-qualification of a rolling cueball.

Jim

dr_dave
09-19-2007, 01:31 PM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote cushioncrawler:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>.....Gearing OE.... completely eliminates throw and cling, regardless of how many fries you eat between shots....<hr /></blockquote>Dr Dave -- Us old "English billiards" playerz could point out that this might be so for the OB trajektory, but cling (kicks) still affekt the trajektory of the qball (which iz of utmost importance to billiards), ie kicks allwayz affekt the deflexion angle (for a rolling qball at least).

Kum to think of it, cling will (can) often shorten the roll distance for an OB allso. So, the rule (for pool) might be -- "uze gearing OE, plus some extra pace". madMac. <hr /></blockquote>Mac,

Here's the definition of "cling" from my online glossary (http://billiards.colostate.edu/resources/glossary.pdf):

cling: excessive friction and throw caused by non-ideal surface conditions at the point of contact between two balls (e.g., a chalk smudge).

Based on this definition, cling has no effect on a shot with gearing outside English. Also from the glossary:

gearing outside English: the amount of outside English that results in no sliding between the cue ball and object ball during contact. Instead, during contact, the CB rolls on the OB like two meshing gears. The result is no throw.

How do you define "cling" and "gearing outside English," and why do you think the CB's or OB's motion will be affected by increased friction if there is no sliding?

Regards,
Dave <hr /></blockquote>I think maybe you missed his semi-qualification of a rolling cueball.<hr /></blockquote>Jim,

Thanks for pointing this out. I did miss his parenthetical. However, the phrase "gearing outside English" really applies only for a stunned CB. With rolling, there will be some sliding (and not gearing) during contact. In that case, cling (increased friction) will have some effect (per TP A.24 (http://billiards.colostate.edu/technical_proofs/new/TP_A-24.pdf)).

Regards,
Dave

SKennedy
09-19-2007, 02:26 PM
Ditto!

cushioncrawler
09-19-2007, 06:47 PM
<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote cushioncrawler:</font><hr><blockquote><font class="small">Quote dr_dave:</font><hr>.....Gearing OE.... completely eliminates throw and cling, regardless of how many fries you eat between shots....<hr /></blockquote>Dr Dave -- Us old "English billiards" playerz could point out that this might be so for the OB trajektory, but cling (kicks) still affekt the trajektory of the qball (which iz of utmost importance to billiards), ie kicks allwayz affekt the deflexion angle (for a rolling qball at least). Kum to think of it, cling will (can) often shorten the roll distance for an OB allso. So, the rule (for pool) might be -- "uze gearing OE, plus some extra pace"...<hr /></blockquote>Mac, Here's the definition of "cling" from my online glossary (http://billiards.colostate.edu/resources/glossary.pdf):

cling: excessive friction and throw caused by non-ideal surface conditions at the point of contact between two balls (e.g., a chalk smudge).

Based on this definition, cling has no effect on a shot with gearing outside English. Also from the glossary:

gearing outside English: the amount of outside English that results in no sliding between the cue ball and object ball during contact. Instead, during contact, the CB rolls on the OB like two meshing gears. The result is no throw.

How do you define "cling" and "gearing outside English," and why do you think the CB's or OB's motion will be affected by increased friction if there is no sliding?Regards, Dave<hr /></blockquote>Dr Dave -- I myself am happy to have a wider definition for GOE. I dont see the need to restrict GOE to stunshots only -- I am happy to call it GOE az long az there iz zero sliding in the XY (horizontal) planes, even if there iz sliding in the Z (vertical) plane.

For sure, for a stunshot, with GOE, there can be no cling (ie if there iz no sliding then there iz no friktion) even if there iz chalk in the contact. And, for sure, if there iz no friktion then there can be no cling-effekt on pace or angle for the OB, nor for the QB.

My earlyr comment that cling affekted a rolling QB's deflexion angle woz based on there being Z-plane ball'to'ball slippage (and hence Z-plane friktion) (like Jim sez).

If the definition of cling inkloodz the wordage "excessive friction and throw" then i am correct. If u took out "friction and" then i would be incorrect.

I woz going to add....
.....[But, all the same, Dr Dave iz not correct to say that "cling has no effect on a shot with gearing outside English, but Dr Dave's statement would be correct if he took out "a shot" and replaced it with "throw"].
But i then saw that (Dr Dave's) GOE iz itself defined for the special case of stun, so Dr Dave's statement iz nearnuff correct.

But, if so, then Dr Dave's wording iz klumzy -- better that it said that --- "cling has no effect on a shot with gearing outside English koz cling cannot exist". Or, perhaps --- "cling cannot happen if a shot haz GOE".

madMac's cling/GOE can shorten the OB roll distance, but of course Dr Dave's cling/GOE karnt. madMac.

Jal
09-19-2007, 09:40 PM
Mac, I think you might agree that there is a class of shots for which cling/skid/kick/ will have no effect, in theory, even if there is sliding at the start of impact. Whenever normal friction, by itself, would be enough to bring the balls into a mutual rolling state (gearing) during impact, any additional friction is superfluous. This can happen at, say, mild cut angles (&lt;30 degrees) with some follow or draw and no outside english, or at larger cut angles with more follow or draw and near outside "gearing" english (ie, the relative surface speed in the horizontal direction is near zero, but not in the vertical).

But I think the case of a fully rolling (drawing) cueball lies outside this class for all cut angles, as you've pointed out.

An interesting point, and one that is probably not intuitively obvious, is that it gets harder to immunize yourself against cling with outside english as the cut angle increases. That's because the difference in spin that produces max throw in one direction and max throw in the opposite direction - we're talking stun or near stun here - diminishes, and ultimately becomes zero at 90 degrees. It's only within this range of spins, more or less, that cling will be held at bay, along with the effects you've been discussing.

Jim

cushioncrawler
09-19-2007, 10:25 PM
<blockquote><font class="small">Quote Jal:</font><hr> Mac, I think you might agree that there is a class of shots for which cling/skid/kick/ will have no effect, in theory, even if there is sliding at the start of impact. Whenever normal friction, by itself, would be enough to bring the balls into a mutual rolling state (gearing) during impact, any additional friction is superfluous. This can happen at, say, mild cut angles (&lt;30 degrees) with some follow or draw and no outside english, or at larger cut angles with more follow or draw and near outside "gearing" english (ie, the relative surface speed in the horizontal direction is near zero, but not in the vertical).

But I think the case of a fully rolling (drawing) cueball lies outside this class for all cut angles, as you've pointed out.

An interesting point, and one that is probably not intuitively obvious, is that it gets harder to immunize yourself against cling with outside english as the cut angle increases. That's because the difference in spin that produces max throw in one direction and max throw in the opposite direction - we're talking stun or near stun here - diminishes, and ultimately becomes zero at 90 degrees. It's only within this range of spins, more or less, that cling will be held at bay, along with the effects you've been discussing...<hr /></blockquote>Jim -- Yes, if gearing woz going to happen (ie inevitable, ie with ordinary friktion), then it makes sense that any cling wont make any difference to the throw (or to anything else). This inevitability-faktor would depend on the qball spin rate (w) and on the change in center'to'center velocity (delta V) -- ie if deltaV/w woz larger than ???? then gearing would be inevitable, and cling wouldnt matter. And az u say this would never happen for a rolling qball.

Re the difference in spin rate between max throw in one direction and the other -- i have a feeling that i agree that this diff in spin rate gets smaller az cut angle inkreecez, and, worse, the dead bit (of spin rate) in the middle gets smaller allso (ie the range where gearing iz inevitable), hence the friendly range(s) adds to even less. Good stuff.

I suppoze that this means that u can have cling (ie higher friktion faktor) but zero cling-effekt (ie zero extra throw). Dr Dave will havta modyfy hiz definition(s). Hmmmm -- I can see a new term -- "naturally developed gearing" or somesuch. madMac.

wolfdancer
09-19-2007, 10:45 PM
Do you guys take this stuff to the pool table when you play?
It sounds like a classic case of "Paralysis by analysis"
As a technical discussion among engineers, scientists, it's got to be quite interesting...unfortunately I skipped school the day they taught them subjects...and believe Efran skipped that day also....
I know the 30 yr old Alex would have loved this stuff, but sadly he just passed away....
web page (http://www.boston.com/news/local/massachusetts/articles/2007/09/11/death_of_gifted_parrot_stuns_scientists/)

dr_dave
09-20-2007, 08:22 AM
<blockquote><font class="small">Quote Jal:</font><hr>An interesting point, and one that is probably not intuitively obvious, is that it gets harder to immunize yourself against cling with outside english as the cut angle increases. That's because the difference in spin that produces max throw in one direction and max throw in the opposite direction - we're talking stun or near stun here - diminishes, and ultimately becomes zero at 90 degrees. It's only within this range of spins, more or less, that cling will be held at bay, along with the effects you've been discussing.<hr /></blockquote>Jim,

Excellent point! FYI, you can see this visually in the plots on pages 3-7 of TP A.28 (http://billiards.colostate.edu/technical_proofs/new/TP_A-28.pdf). The throw curves get steeper at the zero-throw gearing point as cut angle increases.

However, I think the spin range for less throw is not as small as you suggest (see the plots). Also, at large cut angles (thin cuts), English is too dangerous to use any (except for pocket hangers). Too much accuracy is required to trust judgment of and compensation for squirt and swerve.

Regards,
Dave

dr_dave
09-20-2007, 08:33 AM
<blockquote><font class="small">Quote wolfdancer:</font><hr> Do you guys take this stuff to the pool table when you play?
It sounds like a classic case of "Paralysis by analysis"<hr /></blockquote>Wolfie,

I'm disappointed in you. It's ridiculous to imply people would think through this level of detail at the table. That's not the point of these types of discussions. The point is: sometimes, useful insight, understanding, and knowledge can be derived from theoretical studies. And this stuff can be useful at the table. For example, see all of the throw conclusions listed on page 6 of my June '07 throw summary article (http://billiards.colostate.edu/bd_articles/2007/june07.pdf). Top players probably know most of this stuff intuitively (and probably subconsciously), and they automatically adjust their aim to compensate for the different effects. However, people that have misconceptions about these concepts will often miss shots because of what they thought was correct was far from the truth. I think a little understanding (and a lot of intelligent practice) can go a long way to helping somebody improve faster.

Regards,
Dave

Deeman3
09-20-2007, 08:38 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> Also, at large cut angles (thin cuts), English is too dangerous to use any (except for pocket hangers). Too much accuracy is required to trust judgment of and compensation for squirt and swerve.

<font color="blue"> Although not qualified for this discussion, I have to somewhat disagree with this portion as, in my opinion, with many years of practice and, perhaps, too much overuse of outside on very thin cuts, it is not that difficult to control and,in many cases, comes in real handy to avoid opposite corner and sometimes, across side scratches that, otherwise, are almost certain in some of those thin cuts. If it takes a thousand shots to become proficient, it takes thousand shots. If hangers are all we save this for, we restrict our position and recovery game quite a bit, I think.</font color>

<hr /></blockquote>

dr_dave
09-20-2007, 08:40 AM
This is not the first time this topic has been discussed. If people want more supporting arguments, see the pertinent links under "mental aspects" here (http://billiards.colostate.edu/threads.html). I will continue to fight the "anti-science" crowd every time somebody brings this sort of thing up.

Regards,
Dave

<blockquote><font class="small">Quote dr_dave:</font><hr> <blockquote><font class="small">Quote wolfdancer:</font><hr> Do you guys take this stuff to the pool table when you play?
It sounds like a classic case of "Paralysis by analysis"<hr /></blockquote>Wolfie,

I'm disappointed in you. It's ridiculous to imply people would think through this level of detail at the table. That's not the point of these types of discussions. The point is: sometimes, useful insight, understanding, and knowledge can be derived from theoretical studies. And this stuff can be useful at the table. For example, see all of the throw conclusions listed on page 6 of my June '07 throw summary article (http://billiards.colostate.edu/bd_articles/2007/june07.pdf). Top players probably know most of this stuff intuitively (and probably subconsciously), and they automatically adjust their aim to compensate for the different effects. However, people that have misconceptions about these concepts will often miss shots because of what they thought was correct was far from the truth. I think a little understanding (and a lot of intelligent practice) can go a long way to helping somebody improve faster.

Regards,
Dave <hr /></blockquote>

dr_dave
09-20-2007, 08:54 AM
<blockquote><font class="small">Quote Deeman3:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr> Also, at large cut angles (thin cuts), English is too dangerous to use any (except for pocket hangers). Too much accuracy is required to trust judgment of and compensation for squirt and swerve.

<font color="blue"> Although not qualified for this discussion, I have to somewhat disagree with this portion as, in my opinion, with many years of practice and, perhaps, too much overuse of outside on very thin cuts, it is not that difficult to control and,in many cases, comes in real handy to avoid opposite corner and sometimes, across side scratches that, otherwise, are almost certain in some of those thin cuts. If it takes a thousand shots to become proficient, it takes thousand shots. If hangers are all we save this for, we restrict our position and recovery game quite a bit, I think.</font color><hr /></blockquote><hr /></blockquote>Deeman,

Your point is well taken. Maybe "hangers" was a bit extreme, and maybe we should say how "thin" we're talking about ... and how close the CB is to the OB.

Would you use English on a long shot with a very thin hit, with the OB a few feet from a tight pocket?

Dave

Deeman3
09-20-2007, 09:01 AM
<blockquote><font class="small">Quote dr_dave:</font><hr>
Would you use English on a long shot with a very thin hit, with the OB a few feet from a tight pocket?

Dave <hr /></blockquote>

<font color="blue"> No, not unless the reward for that shot positionally was worth the eveluated risk but, of course, that was not how it was described. /ccboard/images/graemlins/grin.gif </font color>

dr_dave
09-20-2007, 09:09 AM
<blockquote><font class="small">Quote Deeman3:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>
Would you use English on a long shot with a very thin hit, with the OB a few feet from a tight pocket?<hr /></blockquote>
<font color="blue"> No, not unless the reward for that shot positionally was worth the eveluated risk but, of course, that was not how it was described. /ccboard/images/graemlins/grin.gif </font color><hr /></blockquote>Good answer! Are you sure you weren't a lawyer in one of your past lives?

Dave

Deeman3
09-20-2007, 09:15 AM
<blockquote><font class="small">Quote dr_dave:</font><hr> Are you sure you weren't a lawyer in one of your past lives?

Dave <hr /></blockquote>

<font color="blue"> No but I fathered one! /ccboard/images/graemlins/confused.gif </font color>

SKennedy
09-20-2007, 09:30 AM
I concur, especially for those of us whose shape forces us to make those type of shots much more often than we should.

dr_dave
09-20-2007, 11:03 AM
<blockquote><font class="small">Quote SKennedy:</font><hr> I concur, especially for those of us whose shape forces us to make those type of shots much more often than we should. <hr /></blockquote>Although, the people who often don't get good shape are probably the same people who should think twice before using English on long, thin cuts.

Dave

SKennedy
09-20-2007, 11:15 AM
So true!

wolfdancer
09-20-2007, 11:39 AM
Dr. Dave, I hope you know that I like to rib you guys about this stuff....since it's all way over my head....
I think it's very useful to have all this knowledge, the physics and mechanics that govern any sport...but I do think you have to "forget" it at the conscious level when you play, and trust your mind-body connection to deliver....
I find the discussions interesting, even if I haven't a clue what is being discussed....
I've been reading Bob Jewett's articles for many years now,and while is is very technical...it's always been "great stuff"
Here's a kid from your neck of the woods that "plays" by feel...
couple of more years, I'll be just like him....playing in diapers
web page (http://video.aol.com/video-detail/2-year-old-has-perfect-golf-swing/3191908942)

wolfdancer
09-20-2007, 11:45 AM
anti-science ??????? that I'm not....I've bought some very technical books in the past on another sport, golf. And I read all the technical stuff behind the latest improvements in equipment. I guess I might have hit a sore spot...and I'll stop kidding about the subject.
Geez,anti-science...is that worse then being called a liberal down in the riff raff section here?

dr_dave
09-20-2007, 11:48 AM
<blockquote><font class="small">Quote wolfdancer:</font><hr> Dr. Dave, I hope you know that I like to rib you guys about this stuff....since it's all way over my head....
I think it's very useful to have all this knowledge, the physics and mechanics that govern any sport...but I do think you have to "forget" it at the conscious level when you play, and trust your mind-body connection to deliver....<hr /></blockquote>I totally agree that when you are down in your stance and about to execute your stroke, you should have singular focus and concentration dedicated to delivering the cue at the desired speed to hit the CB at the desired spot. All of the thinking, analyzing, and strategizing should be done before you get into your stance.

Regards,
Dave

PS: I know you like to rib the techies; but anytime I think you are "out of line" I will chime in.

Jal
09-20-2007, 12:06 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>...However, I think the spin range for less throw is not as small as you suggest (see the plots).<hr /></blockquote>Thank you Dr. Dave for your always generous comments.

I'm not sure if you're refering to the more or less straight portions of the curves surrounding zero/gearing english? If so, I was thinking of higher shot speeds than shown in your graphs, and perhaps even more severe cut angles than 60 degrees, though that's pretty severe, for sure.

With regard to cueball speed, I've always wondered why the range in your plots is so small. Some books, for instance, consider slow to be, say, zero to around lag speed (~ 4 mph); medium enough to go two to three table lengths on a lag type shot (~ 4 to 8 mph); and fast beyond 8 mph, more or less. However, with further thought, the majority of shots are hit relatively slow, perhaps at lag speed or less? That would make the ranges in your plots more applicable to the typical situation.

Still though, TP A.28 uses just 3.6 mph (1.6 m/s) for top speed. This seems a bit extreme, even though I see your point, if that is your point (per last paragraph). Can you clarify this a little?

<blockquote><font class="small">Quote dr_dave:</font><hr>Also, at large cut angles (thin cuts), English is too dangerous to use any (except for pocket hangers). Too much accuracy is required to trust judgment of and compensation for squirt and swerve.<hr /></blockquote>I think this is one of the very practical lessons to be learned from your many labors on throw. On extreme cuts, it's unlikey you're going to get near exact gearing english, and this makes throw fairly unpredictable when you're within the straight portions of the curves. If you use enough excess spin to *safely* throw the cueball "backwards", you're probably going to lose much of the throw effect since it drops off rapidly (especially at the higher speeds mentioned above).

So why not use the vertical center-axis on severe cuts where throw is pretty small anyway, thus eliminating the additional difficulties you mentioned? This is a change I've made to my approach to these shots, which sprang from the theory.

Jim

SKennedy
09-20-2007, 12:16 PM
Like you Wolfie, I play by "feel", which is why maybe I'm not all that good. I know I use my knowledge of the game, but my knowledge was gained by practice and play over the years and just something that now comes naturally. I still learn and there is still much for me to learn. I am a so-called "scientist", but I play pool for pure enjoyment of the game. I do appreciate the finer points of it, and certainly appreciate the physics behind it, but rest assured I'm not thinking "physics" when I'm stroking. Bottom line is that I need to know what the balls will do in certain situations. Having said all that, maybe I should apply more science. I played last night for the first time in about 3 weeks and expected to be a little "rusty." I miscued while breaking and sent the cue ball flying off the table, missed about 4 simple combination shots (which I don't like anyway), and lost several games to a guy that shouldn't beat me at all. I think it was the poorest I've played in 20 years. I kept overcutting the ball, even when I thought I was correcting for it. After about 2 1/2 hours of frustration I finally started playing better. I was playing so poorly I was afraid my opponent would think I was intentially missing and pulling a hustle. All the "science" in the world couldn't help me last night...just pure fundamentals and a good kick in the pants was all I really needed (and maybe a stiff drink)!

wolfdancer
09-20-2007, 12:28 PM
pool is like golf in that you can't expect to play your best, to your ability, after taking some time off. Chuck Hogan has done some research on this, and after a short time...about 72 hours, I believe...the so called muscle memory begins to dissipate.
the "positive" thing about your "poor" play is that your misses were consistent...overcutting them...probably an alignment error, that's easy to correct as opposed to my military style misses ..left,right, left...
As to losing to a guy you should have beat....you might now
have a "customer" The real secret to sports betting is to find someone below at your level, but who also believes he is better.

Deeman3
09-20-2007, 12:41 PM
Wolfdancer,

I agree with your comment on conscience thought in a shot. In particular, inside english is where, if I try to make a conscience effort to "adjust" for the throw, I'll miss the shot. Fran and I discussed an inside english shot a few weeks ago and I nail that, except if I try to make a mental note of where I have to hit the cue ball. Now, what I do mentally is "know" where I intent to hit the object ball toward the rail and that adjusts closer to the pocket with additional speed. If I make the decison and shoot it, I am fine but let me break down that actual process of how much inside, where to hit the cue ball, aim alignment and spped and I can miss it by inches! /ccboard/images/graemlins/shocked.gif

SKennedy
09-20-2007, 01:04 PM
<blockquote><font class="small">Quote wolfdancer:</font><hr> The real secret to sports betting is to find someone below at your level, but who also believes he is better. <hr /></blockquote>
There are many of them around here. Remember, I live in Texas. Pride is plentiful! Unfortunately, I won't play for money to take advantage of someone. There are guys here who deserve to be taken advantage of but I don't. In their mind, they think I'm afraid to play them "when it counts." But the better players know better. I will play a better player for money just for the opportunity to play, but when I play I am ready to lose that money.
And, muscle memory is a very real thing.....I know it is very important in baseball (pitching hitting, fielding), and I'm sure all things (bowling, etc.)

dr_dave
09-20-2007, 03:10 PM
<blockquote><font class="small">Quote wolfdancer:</font><hr> anti-science ??????? that I'm not....<hr /></blockquote>I know you're not. I just like to use that label, metaphorically, whenever somebody makes fun of the techies. I meant no disrespect.

Regards from your fellow science-lover,
Dave

dr_dave
09-20-2007, 03:35 PM
<blockquote><font class="small">Quote Jal:</font><hr>I'm not sure if you're refering to the more or less straight portions of the curves surrounding zero/gearing english?<hr /></blockquote>Yes. I was.
<blockquote><font class="small">Quote Jal:</font><hr>If so, I was thinking of higher shot speeds than shown in your graphs, and perhaps even more severe cut angles than 60 degrees, though that's pretty severe, for sure.<hr /></blockquote>Understood.

<blockquote><font class="small">Quote Jal:</font><hr>With regard to cueball speed, I've always wondered why the range in your plots is so small. Some books, for instance, consider slow to be, say, zero to around lag speed (~ 4 mph); medium enough to go two to three table lengths on a lag type shot (~ 4 to 8 mph); and fast beyond 8 mph, more or less. However, with further thought, the majority of shots are hit relatively slow, perhaps at lag speed or less? That would make the ranges in your plots more applicable to the typical situation.<hr /></blockquote>I think the main reason why I made the range so small it that the curves become flatter at higher speeds. Also, to me, the curves are not useful so much for the exact numbers, but for the trends they reveal. Friction characteristics change with conditions, so one needs to calibrate oneself to know the actual bounds of throw. FYI, I discuss this briefly in my July '07 article (http://billiards.colostate.edu/bd_articles/2007/july07.pdf).

<blockquote><font class="small">Quote Jal:</font><hr>Still though, TP A.28 uses just 3.6 mph (1.6 m/s) for top speed. This seems a bit extreme, even though I see your point, if that is your point (per last paragraph). Can you clarify this a little?<hr /></blockquote>Like you say, many shots are at slower speeds. Also, like I say above, the purpose of the plots is to show the trends, and calibration for conditions is required.

<blockquote><font class="small">Quote Jal:</font><hr><blockquote><font class="small">Quote dr_dave:</font><hr>Also, at large cut angles (thin cuts), English is too dangerous to use any (except for pocket hangers). Too much accuracy is required to trust judgment of and compensation for squirt and swerve.<hr /></blockquote>I think this is one of the very practical lessons to be learned from your many labors on throw. On extreme cuts, it's unlikey you're going to get near exact gearing english, and this makes throw fairly unpredictable when you're within the straight portions of the curves. If you use enough excess spin to *safely* throw the cueball "backwards", you're probably going to lose much of the throw effect since it drops off rapidly (especially at the higher speeds mentioned above).<hr /></blockquote>There are also the issues of squirt and swerve that sometimes make it more difficult to hit the OB at the exact desired point. This might be an even bigger factor than throw variance when using English on thin cuts.

<blockquote><font class="small">Quote Jal:</font><hr>So why not use the vertical center-axis on severe cuts where throw is pretty small anyway, thus eliminating the additional difficulties you mentioned? This is a change I've made to my approach to these shots, which sprang from the theory.<hr /></blockquote>Sounds wise to me.

Regards,
Dave

Chopstick
09-20-2007, 03:40 PM
<blockquote><font class="small">Quote Deeman3:</font><hr> Wolfdancer,

I nail that, except if I try to make a mental note of where I have to hit the cue ball. Now, what I do mentally is "know" where I intent to hit the object ball toward the rail and that adjusts closer to the pocket with additional speed. If I make the decison and shoot it, I am fine but let me break down that actual process of how much inside, where to hit the cue ball, aim alignment and spped and I can miss it by inches! /ccboard/images/graemlins/shocked.gif <hr /></blockquote>

Huh??

I don't know what that was supposed to say. When I read it, it feels like my hair is moving.

For my two cents, I would not use outside english on a long thin cut. I used to do it every time "helping english". I have gotten away from that completely. If the ball was close to the short rail I would use reverse english every time. There are a couple of reasons I say this.

If you are going to shoot this shot, using outside english brings an unforced error into play. You may miss the ball completely. Ball in hand. If you use reverse english and have done it enough times to be comfortable with it if you miss the ball, the cue ball will hit it on the way out. You may still sell out on a shot like that but at least you take ball in hand out of play.

The other thing is that if you are frozen to the long rail or are very near it and are forced to use top, if you use outside english the cue ball will curve away from the object ball increasing the chances of an air ball. Reverse english in this position will curve towards the ball decreasing the chances of ball in hand.

I got this from a Joe Tucker DVD. He discusses it in detail. To me that alone was worth the price of them. Grady had mentioned this before but I didn't pick up on it until I saw Joe demonstrate it.

Jal
09-20-2007, 04:07 PM
<blockquote><font class="small">Quote dr_dave:</font><hr>...<blockquote><font class="small">Quote Jal:</font><hr>With regard to cueball speed, I've always wondered why the range in your plots is so small. Some books, for instance, consider slow to be, say, zero to around lag speed (~ 4 mph); medium enough to go two to three table lengths on a lag type shot (~ 4 to 8 mph); and fast beyond 8 mph, more or less. However, with further thought, the majority of shots are hit relatively slow, perhaps at lag speed or less? That would make the ranges in your plots more applicable to the typical situation.<hr /></blockquote>I think the main reason why I made the range so small it that the curves become flatter at higher speeds. Also, to me, the curves are not useful so much for the exact numbers, but for the trends they reveal. Friction characteristics change with conditions, so one needs to calibrate oneself to know the actual bounds of throw. FYI, I discuss this briefly in my July '07 article (http://billiards.colostate.edu/bd_articles/2007/july07.pdf)....<hr /></blockquote>Thanks for clearing that up...my curiousity is sated. /ccboard/images/graemlins/smile.gif

Jim

cushioncrawler
09-20-2007, 04:25 PM
<blockquote><font class="small">Quote wolfdancer:</font><hr> Do you guys take this stuff to the pool table when you play? It sounds like a classic case of "Paralysis by analysis". As a technical discussion among engineers, scientists, it's got to be quite interesting...unfortunately I skipped school the day they taught them subjects...and believe Efran skipped that day also.... I know the 30 yr old Alex would have loved this stuff, but sadly he just passed away....<hr /></blockquote>Woolfy -- Never. Koz, for one, i have never ever played a game of pool on a pool table. I did for a few minutes hold a proper pool cue (predator??), and hit a proper pool ball (2-1/4") on a proper pool table (9'), but all i did woz to bang a few balls into a corner pocket to check out my natural (the cue's natural) pivot bridge length (backhand pivot, az per Colin Colenso). And, then i forgot what it woz, it woz about 16" i think -- damn, will havta do it again. madMac.

wolfdancer
09-20-2007, 04:49 PM
Nice post...AND I agree with your conclusions. I've only enjoyed reading another guy's posts here, as much as I enjoy Deeman's; Dave Syrja, who sadly passed away.
We better not pile on too many accolades, swelled head and all, but He is the whole package, knowledge, experience, mixed in with some southern humor (most of which escapes me, being a Yankee)

Deeman3
09-21-2007, 07:25 AM
<blockquote><font class="small">Quote Chopstick:</font><hr> <blockquote><font class="small">Quote Deeman3:</font><hr> Wolfdancer,

I nail that, except if I try to make a mental note of where I have to hit the cue ball. Now, what I do mentally is "know" where I intent to hit the object ball toward the rail and that adjusts closer to the pocket with additional speed. If I make the decison and shoot it, I am fine but let me break down that actual process of how much inside, where to hit the cue ball, aim alignment and spped and I can miss it by inches! /ccboard/images/graemlins/shocked.gif <hr /></blockquote>

Huh??

I don't know what that was supposed to say. When I read it, it feels like my hair is moving.

For my two cents, I would not use outside english on a long thin cut. <font color="blue"> No, Chopstick. You mis-read my post, I think. I was saying inside, not outside. I only use outside for position at moderate range or to avoid a skid on some cut shots but also, like you, avoid it on long thin cuts. </font color> I used to do it every time "helping english". I have gotten away from that completely. If the ball was close to the short rail I would use reverse english every time. <font color="blue">Same here or no spin at all. </font color> There are a couple of reasons I say this.

If you are going to shoot this shot, using outside english brings an unforced error into play. You may miss the ball completely. Ball in hand. If you use reverse english and have done it enough times to be comfortable with it if you miss the ball, the cue ball will hit it on the way out. You may still sell out on a shot like that but at least you take ball in hand out of play.

The other thing is that if you are frozen to the long rail or are very near it and are forced to use top, if you use outside english the cue ball will curve away from the object ball increasing the chances of an air ball. Reverse english in this position will curve towards the ball decreasing the chances of ball in hand.

I got this from a Joe Tucker DVD. He discusses it in detail. To me that alone was worth the price of them. Grady had mentioned this before but I didn't pick up on it until I saw Joe demonstrate it.



<hr /></blockquote>

dr_dave
09-21-2007, 08:57 AM
<blockquote><font class="small">Quote Jal:</font><hr> <blockquote><font class="small">Quote dr_dave:</font><hr>...<blockquote><font class="small">Quote Jal:</font><hr>With regard to cueball speed, I've always wondered why the range in your plots is so small. Some books, for instance, consider slow to be, say, zero to around lag speed (~ 4 mph); medium enough to go two to three table lengths on a lag type shot (~ 4 to 8 mph); and fast beyond 8 mph, more or less. However, with further thought, the majority of shots are hit relatively slow, perhaps at lag speed or less? That would make the ranges in your plots more applicable to the typical situation.<hr /></blockquote>I think the main reason why I made the range so small it that the curves become flatter at higher speeds. Also, to me, the curves are not useful so much for the exact numbers, but for the trends they reveal. Friction characteristics change with conditions, so one needs to calibrate oneself to know the actual bounds of throw. FYI, I discuss this briefly in my July '07 article (http://billiards.colostate.edu/bd_articles/2007/july07.pdf)....<hr /></blockquote>Thanks for clearing that up...my curiousity is sated. /ccboard/images/graemlins/smile.gif<hr /></blockquote>Jal,

After sleeping on this, I decided to make the speed range wider, to cover a larger range of shots. Thanks for indirectly encouraging me to do this. Here's the link to the revised TP A.28 (http://billiards.colostate.edu/technical_proofs/new/TP_A-28.pdf). All of the trends are still the same.

Regards,
Dave