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superstroke
01-05-2005, 05:28 AM
It seems to me that a half ball hit will result in pocketing the object ball at different angles. Can someone tell me the angle range? What percentage of shots do you think the half ball hit is used?

randyg
01-05-2005, 05:56 AM
About 30 degrees, in my game it comes up more than 50% of my shots....SPF-randyg

superstroke
01-05-2005, 06:02 AM
IS that it 30? So a 1/2 ball hit will ONLY go into the pocket at 30 degrees.

DennyS
01-05-2005, 07:54 AM
Hi , here is an example of a half ball shot. I hope it can be some use to you. Thanks http://img.photobucket.com/albums/v201/DStewart1/Exampleof30degorhalfballshot.jpg

DavidMorris
01-05-2005, 08:16 AM
<blockquote><font class="small">Quote superstroke:</font><hr> IS that it 30? So a 1/2 ball hit will ONLY go into the pocket at 30 degrees. <hr /></blockquote>
Pretty much, yes. It is possible to transfer forward or reverse spin to an object ball which could cause it to deviate from the 30 degree line somewhat, but for most strokes it would be so marginal as to not significantly affect the angle more than a degree or two in either direction.

Bob Jewett and Fred Agnir are our resident scientists who can speak more to the scientific principles of the collision and angles involved.

dr_dave
01-05-2005, 11:52 AM
<blockquote><font class="small">Quote superstroke:</font><hr> It seems to me that a half ball hit will result in pocketing the object ball at different angles. Can someone tell me the angle range? What percentage of shots do you think the half ball hit is used?<hr /></blockquote>
All of the information you ever wanted to know about the half-ball hit (and more) can be found at the:

dr_dave
01-05-2005, 12:09 PM
<blockquote><font class="small">Quote superstroke:</font><hr> IS that it 30? So a 1/2 ball hit will ONLY go into the pocket at 30 degrees.<hr /></blockquote>

- the April-July'04 and Feb-March'05 instructional articles posted online (http://www.engr.colostate.edu/~dga/pool/bd_articles/index.html) .

Bob_Jewett
01-05-2005, 01:13 PM
<blockquote><font class="small">Quote superstroke:</font><hr> IS that it 30? So a 1/2 ball hit will ONLY go into the pocket at 30 degrees. <hr /></blockquote>
No for two reasons.

First, there is some margin of error because the pocket is more than a millimeter wide. That means that there is a range of cut angles that will go in. There is a simple formula that tells you how wide that angle is for any distance and pocket width, but if the object ball travels the length of your cue to get to the pocket, you have about +-1 degree of slop in the accuracy of your cut.

The second "no" is because if you get a half-ball hit on the object ball -- send the center of the cue ball at exactly the edge of the object ball -- contact-induced throw will reduce the angle to 28 or 29 degrees, depending on what other spin is on the cue ball, speed, ball surfaces, etc. The practical range of control with side spin on the cue ball is perhaps +- 2 degrees from 30 degrees.

But please note: if you have a 32 degree cut, I think it would be folly to try for a half ball hit with a lot of outside english. I think you should just aim for a thinner hit. Unless position requires the side spin, of course.

Cane
01-05-2005, 06:11 PM
Just food for thought... an as someone said, most of the shots I shoot in a game are half ball hits... Think of shooting a gun at the edge of a round barn. If you move to one side or the other, then your contact point actually moves, so, IMHO, you're right. A half ball hit will pocket balls at a variety of angles. My opinion is that approach angles from 30 to 44 degrees will pocket a ball. By approach angle, I mean the difference in angle between a line drawn from the center of the object ball to the center of the cue ball, as it's deviates from the a line drawn through the center of the pocket to through the OB. These hits will, if executed properly, put the OB in the center of the pocket. There must be some deviation of you need to cheat a partially blocked pocket, or need to cheat a pocket for position play.

Later,
Bob

Bob_Jewett
01-05-2005, 06:25 PM
<blockquote><font class="small">Quote Cane:</font><hr> Just food for thought... an as someone said, most of the shots I shoot in a game are half ball hits .. <hr /></blockquote>
By "half ball" you must certainly not mean directing the center of the cue ball towards the edge of the object ball. If you really believe that you can make cut angles of 30-44 degrees with a half ball shot as it's commonly defined, you must be making huge, huge subconscious corrections.

Bob, what do you mean by a "half ball" shot?

superstroke
01-06-2005, 03:43 AM
" My opinion is that approach angles from 30 to 44 degrees will pocket a ball. By approach angle, I mean the difference in angle between a line drawn from the center of the object ball to the center of the cue ball, as it's deviates from the a line drawn through the center of the pocket to through the OB. These hits will, if executed properly, put the OB in the center of the pocket. There must be some deviation of you need to cheat a partially blocked pocket, or need to cheat a pocket for position play."

Later,
Bob
<hr /></blockquote>

GeraldG
01-06-2005, 06:11 AM
The 30 degree "rule" applies to the approximate angle of deflection of the cueball off the object ball after contact, and depends upon whether the cueball is rolling or stunned at contact and the angle of attack producing a contact point that corresponds to somewhere between about a 1/8 ball and 1/2 ball shot. At least that's the way I always understood it. The required angle of attack that is required to POCKET the object ball, that is the angle from which the cueball APPROACHES the object ball, is going to depend entirely upon the position of the object ball in relation to the target pocket and the cueball. I don't understand how a 1/2 ball shot could pocket 50% of the shots you encounter on a table....it certainly won't for me, especially from position left by my opponent. It may work out to a 1/8 ball shot or a 1/4 ball shot or a 3/8 ball shot or whatever, but the angle of deflection of the cueball off the object ball will be something close to 30 degrees for a cueball that is rolling when it contacts the object ball, close to 90 degrees for a cueball that is stunned when it contacts the object ball. This is useful for position play, but has little to do with actually pocketing the object ball.

What I've found is that you have to hit the contact point on the object ball fairly accurately to pocket the ball. The further from the pocket the object ball is, the more critical accuracy becomes. The reason is that if you miss you contact point by, say 1/4 inch, you will miss your intended path of travel for the object ball by 1 inch or so if the object ball has to travel 1 foot. If the object ball has to travel 3 feet, then that miss margin turns into 3 inches by the time the object ball travel 3 feet. (these are approximate numbers for illustration of the point only). So, if a particular ball is 3 feet from the pocket and requires a 1/4 ball hit and you hit it half-ball, you're going to miss the pocket by a foot. However, the angle of cueball deflection is still going to be the same.

Did I miss the point of what you guys are saying, or is my thinking all screwed up here?

dr_dave
01-06-2005, 09:11 AM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> <blockquote><font class="small">Quote Cane:</font><hr> Just food for thought... an as someone said, most of the shots I shoot in a game are half ball hits .. <hr /></blockquote>
By "half ball" you must certainly not mean directing the center of the cue ball towards the edge of the object ball. If you really believe that you can make cut angles of 30-44 degrees with a half ball shot as it's commonly defined, you must be making huge, huge subconscious corrections.

Bob, what do you mean by a "half ball" shot? <hr /></blockquote>
FYI, the illustrations in my online article (http://www.engr.colostate.edu/~dga/pool/bd_articles/april04.pdf), introducing the 30 degree rule, includes many illustrations that might help in this discussion.

Also, the plots and numbers in TP 3.3 (http://www.engr.colostate.edu/~dga/pool/technical_proofs/TP_3-3.pdf) show how the cue ball deflection angle various with ball-hit fraction (1/8, 1/4, 1/2, etc.) and cut angle (the angle between the impact line and the aiming line).

For a 1/2-ball hit, the cut angle is exactly 30 degrees and the deflected cue ball angle is 33.7 degrees.

I hope that helps.

dr_dave
01-06-2005, 09:19 AM
<blockquote><font class="small">Quote superstroke:</font><hr> It seems to me that a half ball hit will result in pocketing the object ball at different angles. Can someone tell me the angle range? What percentage of shots do you think the half ball hit is used?<hr /></blockquote>
FYI, there are several existing threads that already deal with the 30 degree rule and the half-ball hit in great detail. You can locate them quickly from my online list of threads (http://www.engr.colostate.edu/~dga/pool/threads.html).

Bob_Jewett
01-06-2005, 09:38 AM
<blockquote><font class="small">Quote superstroke:</font><hr> It seems to me that a half ball hit will result in pocketing the object ball at different angles. Can someone tell me the angle range? What percentage of shots do you think the half ball hit is used? <hr /></blockquote>
Hi Superstroke,

There seems to be some major confusion about your question. By "half ball hit" do you mean sending the center of the cue ball at the edge of the object ball?

Cane
01-06-2005, 11:06 AM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> By "half ball" you must certainly not mean directing the center of the cue ball towards the edge of the object ball. If you really believe that you can make cut angles of 30-44 degrees with a half ball shot as it's commonly defined, you must be making huge, huge subconscious corrections.

Bob, what do you mean by a "half ball" shot? <hr /></blockquote>

Bob, yes, I do mean that I aim the center of the cue ball at the outside edge of the object ball on these shots, and it does work. As for subconcious adjustments, I had to work on this particular aiming method for 2 months to STOP myself from making subconcious adjustments. Once I stopped doing this, it worked, and it worked perfectly .

Bob, I think you know from personal communications that I have the utmost respect for you and your pool knowledge, so the following is in no way meant to be argumentative, just telling it like it's been shown to me.

All of my pool life, which envelopes nearly a half a century, I believed that there were an infinite number of places you had to aim at balls to make them. More recently, with the past 3 years, I began to believe that I was wrong, there were only 160 places you ever had to hit an object ball to make any shot, that made it a lot simpler, right? Within the past year, from two different sources, whom I will not name, but they dwell here occassionally (Well, one still does, one used to, not sure if he monitors this or not these days), I learned that I was wrong. There are only 6 places that one EVER has to aim a CB at an OB (I'm talking a full ball hit, and 5 aim points on each side of center of the OB) to make any cut shot, combination, carom or bank. The explanation can get into a discertion on a combination of geometry, physics and calculus, but, in simple terms, due to the shape of the table, a pair of perfect squares with holes in the corners of each of the squares, it is impossible for there to ever be any need to send the CB on any more than 6 lines of aim at an OB, the 6th being that nearly 90° cut (88.5° actually).

Now, that being said, there are adjustments that must sometimes be made. Suppose you need to cheat a pocket because of a blocker, or for position, or you have to shoot a bank shot especially hard or soft so that the natural angle of exit of the OB from the rail is altered, then yes, I do deviate from those aim appoaches ever so slightly. Reason for deviation? Because this particular method of aiming ONLY sends the ball to the exact center of the pocket. However, just guessing, I'd say that for 95% of my shots, I use one of those 6 approaches of CB to OB. Going even farther, I'd say that on at least 85% of those shots I only use 3 of those approaches of CB to OB. Of course there will be extreme exceptions, like frozen ball shots, near frozen, extreme masse' shots, adjustments for extreme spin or for finesse speed shots where the balls stay "married" and carry along the same path for an extended dwell time, etc., but in MOST cases this method works perfectly at normal stoke speeds for almost every shot. Hell, it makes bank shots and combinations almost as easy as a cut shot... Only thing I've never been able to apply it to are kick shots which are a whole different story.

I love to teach this method, but when I first explain it, almost everyone has the same reaction I had "Ain't No Way this is going to work". So, in my classes in order to demonstrate it's validity, I use a curtain mounted on an old clothing rack made so that the curtain covers up the table from about a diamond below the side pockets, with the curtain hanging just high enough above the cloth so that the ball will go under it without touching. In other words, the only pockets I can see are the two corner pockets on the end of the table where I'm standing. I'll put an OB on the table on my side of the curtain, anywhere near the center, and the CB a foot or so behind it, then I'll let my students tell me which pocket they want me to shoot the ball into. And it doesn't have to be a pure cut shot, I'll bank to either long corner, cut to the sides, cut to the corners, just whatever they want me to do. Keep in mind that this makes me depend completely on this aiming method, because I can't see the pockets to which I'm shooting or on the long banks, I can't see the rails that I'll be hitting. After a few minutes of this, they're on the tables asking me to show them again what the aim points are, because they didn't pay attention when they didn't think it would work, but they damn sure want to know, now...

I know it sounds like Black Magic to many, but it's not, it's just a pure and simple truism of pool, one of those things that it's just mathmatically impossible for it to NOT work. One of the gentlemen who taught me their variation of this method told me that using this method could actually make playing pool and pocketing balls "BORING". Well, I don't think I'll ever find pool boring. I love the game and can shoot for hours on end just by myself... or at least until my knees and back say "We've had enough, Old Man, time to sit down for awhile". But the plain simple truth is that once this method is learned and trusted and it's hard to trust this when, like me, for nearly half a century of your life you've thought there were an infinite number of approaches to an object ball, it does make pocketing balls so much easier than anyone ever could imagine. If I miss now, it's a stroke problem, a focus problem or a fantastic looking waitress walking by the table (I'm talking about a young lady named Sheila who is our waitress at our regular Sunday Night Tournament, in which I've stayed in the top 3 for 16 weeks in a row)... it's not because of this aiming method.

Actually, anyone can figure out this method, if they just pay attention while practicing. Line up your shots as you normally would, using whatever aiming method or system you normally use, then move your eyes over the center of the cue ball and see where it's aimed in relation to the OB. After a few shots, you'll all of a sudden notice "Geez, I'm aiming the center of the cue ball for "Spot X" on the OB every time for a shot in that range, and for spot Y every time for a shot in that range and for spot Z for every shot in that range." This method is amazing and it will absolutly make pocketing balls much easier and much more consistent than any method I've every tried or used... and I think I've tried about ALL of them. Of course, this, as with all aiming methods (and it's my considered opinion that EVERYONE uses some kind of aiming method or system) will become automatic with practice. I do use the system now, but have practiced it so much that I use it without thought. It's completely automatic and subconcious.

I know I'm getting long winded here, so I'll wind this up with one last paragraph. For the first time in my life, I will, on occasion, intentionally play position for shallow bank shots in 8 ball and 9 ball (which are probably my two least favorite games, but must be played, because that's what everyone wants to play). Banks no longer intimidate me... combinations no longer intimidate me... caroms no longer intimidate me... pocket billiards in general no longer intimidates me... because I now use an aiming method that I completely and absolutely trust and KNOW works and that makes pocketing balls the easiest part of the game. The rest is just getting the rock where I want it and knowing tangent lines and natural roll lines, the only things I have to contemplate on a difficult shot are speed and spin (which I use as little as possible)... The Angles are easy... there are only six... only three that I use on a regular basis...

By the way, I'm leaving in about 30 minutes to get the Lasik done. Over the past couple of days, I've wondered what the balls REALLY look like. If I can see them clearly, where is my game going to go now? BUT, ya know... I'm retired military... I've been shot three times, I've been stabbed twice (pool room discussions in the 80's), I've been in more NCO club and pool room brawls than I can count, but this "CUTTING ON MY EYE" thing has me so shook up that you couldn't pry my butt cheeks apart with the Jaws Of Life thing the firemen use to pry wrecked car doors open.

Later,

Shakin' Bob (shakin', but still making table length 80° cut shots using this method, even with bad eyes).

Qtec
01-06-2005, 12:04 PM
Wow.

Instead of having 167 or 6 or 60 points of aiming, why dont you make it simpler and have just one.
The Ghost Ball. Or to be more specific, the center of the GB.
The point of aiming never changes. Its always the same.

What could be simpler?

Qtec

DavidMorris
01-06-2005, 12:26 PM
<blockquote><font class="small">Quote Qtec:</font><hr>Instead of having 167 or 6 or 60 points of aiming, why dont you make it simpler and have just one.
The Ghost Ball. Or to be more specific, the center of the GB.<hr /></blockquote>
Perhaps I can speak to that, at least from my own perspective. I fully understand the Ghost Ball technique, but I have trouble visualizing and maintaining that visualization of the GB throught the completion of the shot. If I could mark the table where the GB should be it would be different, but I find that my GB "moves" as I move around, whether from walking around the table or getting down on the shot. So I usually aim for the contact point, it's just more natural for me. Yes, I have to compensate on cut shots because the center of he CB doesn't hit the contact point, but that comes fairly natural to me by now I guess.

I know I've heard or read of others that just couldn't get entirely comfortable with the Ghost Ball technique either. My problem with it probably stems from playing pool for long before I was formally introduced to the concept -- I saw the logic of it but it just never felt right to me. I'd be interested in how many other CCB'ers don't entire rely on the GB either.

And I'm intrigued by your technique, Bob. I'd like to know more. I don't suppose you have any video of this demonstration of yours? I'd like to see it in action, if you could capture it and convert it to mpeg or avi.

DialUp
01-06-2005, 12:56 PM
David, I too have trouble with the Ghost Ball. I learned to shoot by trial and error long before I heard of GB...

It just seems silly, to me, to aim at an imaginary ball when I can aim at a real ball. If the cut is too thin, I aim the side of the CB that will hit the OB instead of the center. Either way, I aim at a real ball and I am a pretty good shot maker.

However, I have a friend that always uses the GB method and he plays very close to my speed. He is the only person who has ever told me they use the GB outside of practicing...

I use the GB method to show new players where to aim. Mostly, just to illistrate how the center of the CB to the contact point is rarely the spot to hit.

Qtec
01-06-2005, 01:00 PM
Dont confuse the aiming piont with the contact point.

This is a very commom mistake.

Q

Qtec
01-06-2005, 01:12 PM
[ QUOTE ]
Perhaps I can speak to that, at least from my own perspective. I fully understand the Ghost Ball technique, but I have trouble visualizing and maintaining that visualization of the GB throught the completion of the shot. <font color="red"> Why? Are you looking at the OB or the QB? </font color> If I could mark the table where the GB should be it would be different, but I find that my GB "moves" as I move around, <font color="red"> The contact point shifts with perspective. The center of the GB remains static. </font color> whether from walking around the table or getting down on the shot. So I usually aim for the contact point, <font color="red"> with what? If you aim at the cntact point with the center of the Qb, you will miss! </font color> it's just more natural for me. Yes, I have to compensate on cut shots because the center of he CB doesn't hit the contact point, but that comes fairly natural to me by now I guess <hr /></blockquote> <font color="red"> ??? </font color>

What you think you do, is not neccessarily what you actually do!?
Q

DavidMorris
01-06-2005, 02:05 PM
<blockquote><font class="small">Quote Qtec:</font><hr> with what? If you aim at the cntact point with the center of the Qb, you will miss!<hr /></blockquote>
If you read the end of my post after that, I said that I compensate. I don't aim the center of the cueball at ANYTHING unless I'm shooting a straight in shot. I imagine what part of the CB must hit what part of the OB, and I shoot to mate those two points together.

I'm not saying GB is useless or overrated -- only that it doesn't work well for me. I answered in reply to your question to Bob about why he didn't just use GB, because it seemed you thought everybody should just use GB.

You make it sound as if GB is the only way to successfully aim shots, and that people are using it even if they don't realize it. I disagree.

Qtec
01-06-2005, 02:24 PM
[ QUOTE ]
If you read the end of my post after that, I said that I compensate. I don't aim the center of the cueball at ANYTHING unless I'm shooting a straight in shot. I imagine what part of the CB must hit what part of the OB, and I shoot to mate those two points together.

<hr /></blockquote>

Yes, but HOW?????

Qtec

DavidMorris
01-06-2005, 02:52 PM
<blockquote><font class="small">Quote Qtec:</font><hr> Yes, but HOW?????

Qtec<hr /></blockquote>
I suppose you could say that I line up as if I were going to make a full-ball hit, then pivot off-axis by whatever amount I'm compensating for. That's not exactly what I do, but it's the closest approximation that I can put into words -- it's a feel thing.

I think I see where you're trying to go with this -- you're trying to prove that at the point of contact, the CB will BE the ghost ball, and thus validate the GB aiming theory. Of course the CB will become the GB, that's the definition of a ghost ball. But what I'm saying is that I do not use the GB as an aiming device, i.e. I am not focusing and them aiming at where the center of the CB will be at the point of contact, I'm focusing on where the contact point of the CB will be. It's just a difference of perspective that works better for me. The end result of a (successful) shot will of course be the CB in the GB position, but that is just not how I visualize the shot when I set it up.

Capiche?

Bob_Jewett
01-06-2005, 02:54 PM
<blockquote><font class="small">Quote Cane:</font><hr> Bob, yes, I do mean that I aim the center of the cue ball at the outside edge of the object ball on these shots, and it does work. As for subconcious adjustments, I had to work on this particular aiming method for 2 months to STOP myself from making subconcious adjustments. Once I stopped doing this, it worked, and it worked perfectly .
... <hr /></blockquote>
If the idea works for you, fine. But please look at my posting about the separation between systems based on psychology and those based on geometry. There is no point in trying to justify a belief system with geometry. Your system is geometrically false, but it works for you psychologically.

GeraldG
01-06-2005, 03:15 PM
Here's what I do (fwiw).....right or wrong...

I determine the point on the object ball where the (imaginary) line from the pocket through the object ball exits the object ball. That is my point of intended contact on the object ball. Then I get behind the cue ball a couple of feet and try to see the line from the cueball to the object ball that will put the cueball in position so that the proper point of the cueball will contact the proper point of the object ball. In order to do that, I have to try to "see" the cue ball in a static state in position at the object ball, for a moment anyway. Once I can visualize that, I can see the line I need from the cue ball to the object ball. That is the line that I align my stance, etc., with. I decide on spin, etc. before I choose my line because english will change the position of my bridge hand, etc. If I get down on a line and then adjust for english, it's going to throw other parts of my setup off and I'll feel off-balance. If I choose a line to begin with that accounts for english, then I don't have to worry about whether my stroke is straight or not.

So, I guess in a way I use the GB technique. I was taught this technique by Johnny Archer. I had a LOT of trouble before he showed me the technique, because I was lining up on a line straight from the center of the cueball to the center of the object ball, then trying to pivot around to adjust for where I actually needed the cueball to strike the object ball and then pivoting more to adjust for the cue position for english. All the while, my feet were already planted in position because I was already down on the shot, and all that pivoting around would have me sort of "fighting myself"...I was actually in my own way. My stroke would actually end up brushing the side of my body sometimes, and my stroke was tense and tentative because I was fighting myself so much. I was subconsciously aware that my stroke wasn't going to be straight, so I was trying to "force" it straight. When you're doing that it's almost impossible to have a loose, relaxed stroke.

DavidMorris
01-06-2005, 03:23 PM
Actually, Gerald, what you describe is almost how I do it. The point is we're focused on the line to the OB, not the ghost ball itself.

<blockquote><font class="small">Quote GeraldG:</font><hr> I had a LOT of trouble before he showed me the technique, because I was lining up on a line straight from the center of the cueball to the center of the object ball, then trying to pivot around to adjust for where I actually needed the cueball to strike the object ball and then pivoting more to adjust for the cue position for english. All the while, my feet were already planted in position because I was already down on the shot, and all that pivoting around would have me sort of "fighting myself"...I was actually in my own way. <hr /></blockquote>
You will definitely have a problem if you get down on the shot and then try to determine your aimpoint and adjust your stroke. I sometimes fall into that trap when I'm rushing for some reason, and have to stop myself, stand up, and think the shot through before getting down again.

To clarify: I do NOT get down over the shot and then pivot around trying to find the right adjustment on the CB, although it might have sounded that way from my description above. I visualize the path to bring the contact points together before getting down on the shot. I just had a hard time finding words to describe what to me is an automatic "feel" thing, hence my crude description of pivoting from a centerball hit.

Which is another reason why GB is so often used to teach beginners -- it's a concept that is much easier to convey than a "feel" shot. I've used it myself when introducing new players to the game, because it is a visual aid. I just don't think in those terms when I'm playing.

Qtec
01-06-2005, 03:28 PM
[ QUOTE ]
So, I guess in a way I use the GB technique. <hr /></blockquote>
Yes you do. Although you match up contact points[ which are different than aiming points{ except on a straight shot} ],you still end up aiming for the same point.[ using no E].

Q

Cane
01-06-2005, 08:17 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr>
If the idea works for you, fine. But please look at my posting about the separation between systems based on psychology and those based on geometry. There is no point in trying to justify a belief system with geometry. Your system is geometrically false, but it works for you psychologically. <hr /></blockquote>

Bob, eyes are still very itchy and uncomfortable from the surgery today, so I'll definitely look at your posting on the seperation between systems tomorrow after I get rid of these ugly looking ski goggle things I have to wear, but... I disagree that this aiming method is geometrically flawed. I am an engineer and I literally spent days graphing, calculating and drawing out different scenarios trying to disprove this aiming method. I have, in my office, a stack of papers, probably 40 more pages, of calculations where I tried everything I could to disprove this method and I could not do it. The aiming method is geometrically sound. The only time it does not work is when I doubt it and make an adjustment, as in a situation when I think "Whew... that looks like it's going to be just a hair to thin of a hit" then I'll adjust it just a hair, and sure enough, I'll miss it a bit full. If I stick with this method (and I do prefer to call it a method, not a system), then I make balls, and I make them center pocket. If I let those little subconcious or psychological adjustments creep in, I MISS. I've been using it long enough now, and have practiced it enough now, that I rarely let the "doubts" slip in. The only time I do, is if it's a very long night and I'm very tired. At that point, I'm not focusing anyways, so all kinds of bad things happen.

As for the GB system, one thing I never did like about it was that you were aiming at an imaginary point in the middle of nowhere. With this method, you are always aiming a part of one object (the cue ball) to part of another object (the OB), so there is no aiming into space or at an imaginary point.

I'll be happy to expound later, but the ski goggle things are a very dark tint and it's difficult to type when you're sitting a brightly lit room yet feel like your in absolute dark! Not so easy to see the screen without cheating and taking off the goggles for a few seconds

By the way, even though the eyes are still itchy and driving me out of my tree, at 4 1/2 hours post op, I can see much better than I ever could. I think I'm going to love this Lasik stuff!!! The Dr said it would be much better by morning, even better by end of the weekend and possibly even better yet by the end of next week. He said that in some cases, it can get better for up to a few months!!! I can't imagine that it gets better. Yes, my eyes feel like they're full of dust right now, but I still see better than I ever have!

Later,
Bob

Bob_Jewett
01-07-2005, 02:01 PM
<blockquote><font class="small">Quote Cane:</font><hr>... but... I disagree that this aiming method is geometrically flawed. I am an engineer and I literally spent days graphing, calculating and drawing out different scenarios trying to disprove this aiming method. I have, in my office, a stack of papers, probably 40 more pages, of calculations where I tried everything I could to disprove this method and I could not do it. The aiming method is geometrically sound. <hr /></blockquote>

The question was about a half ball hit. I define a half ball hit as a shot in which the center of the cue ball travels in a straight line that is tangent to the object ball. (Less rigorously, you shoot the center of the cue ball at the edge of the object ball.) Without throw, it is trivial to show that the cut angle of such a shot is 30 degrees. This is very simple geometry and the demonstration is very simple. I assume that you can figure out such a demonstration for yourself (or you have forgotten your high school geometry).

I'm left with the conclusion that you do not mean the same thing I do by "half ball hit." Bob, what do you mean by "half ball hit?"

GeraldG
01-07-2005, 02:43 PM

Cane
01-07-2005, 11:01 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> I assume that you can figure out such a demonstration for yourself (or you have forgotten your high school geometry).

I'm left with the conclusion that you do not mean the same thing I do by "half ball hit." Bob, what do you mean by "half ball hit?" <hr /></blockquote>

/ccboard/images/graemlins/smile.gif No, Bob, I haven't forgotten my high school geometry, or College Calc or Physics or Engineering Physics, and it requires a good knowledge of all of these to do the work I did in an attempt to disprove this aiming method.

Before I go any further, I want to reiterate that I am a huge fan of yours and many of your systems and methods. I have won many a C-note on your frozen ball and near frozen ball carom system, but as for this particular aiming method, which is NOT the only valid aiming method in the billiards world, I must stand firm that it works and it works better than any I've ever tried. I think of it like a scientific refinement of a combination of the GB method and the Contact point to Contact point.

In any case, I do mean exactly what you thought I did by a half ball hit... aiming the center of the cue ball at the outside edge of the object ball. This WILL make balls in a particular range. Center of cue ball to quarter of OB will make them in another range, quarter of cue ball to outside edge of OB will make them in another range, etc, etc, etc. Where this confuses many is that the minute changes in distance and angle make your contact patch move slightly, even though your appoach angle is exactly the same. One way I demonstrate this is by showing someone the ghost ball method. I'll set up a long shot not exactly 30°, but somewhere in the neighborhood of 30°to 35° and literally put a real ball against the object ball so that it would be an "on shot", have them line up to hit the ghost ball full, then before they shoot, remove the ghost ball and ask them where the center of the cue ball is pointed. They'll inevitably say "Well, right at the edge of the object ball." Then I'll move the cue ball 6 inches or so to the right or left, to make the cut a little tougher angle, line up a ball in place of the ghost ball again, and have them line up to hit it full, remove the ghost ball and again, they see that the cue ball's center line is lined up EXACTLY with the outside edge of the object ball. It simply amazes them that they only have to aim at one place to make any ball in that particular range of angles. I do the same thing for the other 5 aim points, and they're amazed even more. The only people I have trouble teaching this too are those who are convinced and have been convinced all of their life, that there are an almost infinite number of angles to shoot at an object ball. The simple truth is that there ARE an almost infinite number of contact patches to hit, but there are only a few angles of approach to a cue ball to hit those patches.

I use this method and no other. This afternoon, for the first time, I shot pool with 20/20 vision... first time in my life I've been able to see that good. I was banking, shooting combinations, making table length thin cut shots... I was shooting the best pool I have since I quite the game in 1988. I've only been playing again since April of 2004. Anyways, during that marathon of pool, one game of 14.1, which I won 150 to 21 and an uncountable number of games of 9-ball combined, I only used those predifined angles of approach of CB to OB to make every shot, banks and combinations included. I did have to kick out of a few situations, but that, as I said before, is a whole different world to which this aiming method cannot be applied. Regardless, my "make rate" was VERY HIGH. So high, in fact, that the table we were on drew a crowd side betting... not on whether I'd win, but whether I'd run from break. The method is that precise in both theory and application.

Well, like I said in another post... Casino time. I'm playing with someone elses money on the tables tonight! *S*

later,
Bob

SPetty
01-08-2005, 10:58 AM
Hi Bob,

Any chance I could talk you into stopping by PettyPoint on your way down to South Padre Island and bring that little book of yours where you tried to disprove that theory you're discussing?

Although I've had several people try to tell me / teach me about this aiming system - sorry, method - you're talking about, I can't get it. I can't believe that you can hit the ball in this one place and it will go smack dab into the center of the pocket whether the angle is this angle, or the other angle. I can't help but think that if you hit the ball with one particular incoming angle, there will be one particular outgoing angle.

Most of the converts that believe in it can't explain why it works. They just say "believe it and it will happen". I really have a hard time with that. But I'd sure like to hear and see your analysis of it, because it sounds like you would at least understand my skepticism. I'd offer up a nice place to stay overnight (you gotta climb stairs), and feed you too, and pay a lesson fee if that helps, if you can work it into your plans. Please let me know.

DavidMorris
01-08-2005, 11:15 AM
Bob, I want more info. I'm with SPetty -- I believe you're sincere but I can't wrap my brain around what you're saying. It would seem to defy physics, so there must be some sort of inate "compensation" for the different angles, because contacting the ball in the same place with the same CB-to-OB angle will result in the same OB-to-pocket angle everytime (discounting throw). But I don't care if it IS a subconcious or psychological compensation -- if it works reliably to make aiming as foolproof as you claim, then I'm interested in learning more about it.

For instance, you mention the 5 different points of aim, but you don't give specifics -- you only talk about "half-ball hit" which is only one point of aim.

Enquiring minds want to know!!!

Alfie
01-08-2005, 12:54 PM
<blockquote><font class="small">Quote Cane:</font><hr> Where this confuses many is that the minute changes in distance and angle make your contact patch move slightly, even though your appoach angle is exactly the same. <hr /></blockquote>distance between what? angle between what?

<blockquote><font class="small">Quote Cane:</font><hr> The simple truth is that there ARE an almost infinite number of contact patches to hit, but there are only a few angles of approach to a cue ball to hit those patches. <hr /></blockquote>does this method work for combination shots too?

jjinfla
01-08-2005, 05:13 PM
Bob,

Are you saying the path the OB takes to the pocket will be identical when you move the CB?

Say OB on spot - CB 4 balls from rail on headstring. Half ball hit moves the OB down a path to the center of the pocket. Now if you move the CB one ball left or right and shoot a half ball hit will the OB still stay on the same identical path to the pocket? Or will the paths be slightly left or right of the first path? I would think the paths would be slightly different.

Of course I didn't do too well in Physics.

Jake

Cane
01-08-2005, 05:56 PM
Yes, that is absolutely what I am saying. This will work to a certain point then the line of aim changes exactly (at about 45° angle from cue ball path to OB as opposed to OB path to pocket, approximately 0.562" or a quarter of a ball. There IS NO IN BETWEEN.

I"m working on some simple to understand drawings that will demonstrate this and show how it works... I don't have ACAD, so I'm doing it with MS Paint.... may take awhile! WHen they're done, I'll post them on the web.

Later,
Bob

randyg
01-08-2005, 06:14 PM
Well Bob, you got yourself into it now. Let me know when I should help....SPF-randyg

Alfie
01-08-2005, 06:54 PM
<blockquote><font class="small">Quote randyg:</font><hr> Let me know when I should help <hr /></blockquote>feel free

Cane
01-08-2005, 07:56 PM
Randy, Jump in anytime you want. I knew this would draw controversy, but I just couldn't help myself! LOL

Right now, I'm about to head for the Tylenol bottle. Since my last post, I've been trying to draw these things out on MGI PhotoSuite and its like drawing with an Etch-a-Sketch.

By the way, folks, now that he's volunteered to chime in, Randy is the one who first introduced me to this system in January of last year. He is a master at it! Before that, I relied on contact point to contact point system. It worked OK, but it's difficult, at least for me, to aim to a point on an object ball with a point on a cue ball that I cannot even see. With this method, you are aiming something visible at something visible... no guessing. This method is a killer. Combination shots without thought... bank shots without thought... carom shots without thought...

Okie Dokie, Randy. Help me out with the explanation while I work on the confounded drawings (gonna get a new computer one of these days and the FIRST thing I'm going to do is install AutoCAD on it!!!

Later,
Bob

GeraldG
01-08-2005, 08:08 PM

I played a little with this in practice last night, and I had a match today and during practice I played around with it a little more. I didn't have much time and I don't fully understand it yet, but from what I little I saw, there may be something to this.

I need to understand it a little better, though...so I can work out an approach to learning how to use it.

jjinfla
01-09-2005, 07:28 AM
<blockquote><font class="small">Quote DennyS:</font><hr> Hi , here is an example of a half ball shot. I hope it can be some use to you. Thanks http://img.photobucket.com/albums/v201/DStewart1/Exampleof30degorhalfballshot.jpg <hr /></blockquote>

Using Denny S's diagram if you move the CB left or right and still use a half ball hit the line from CB to OB will move. And then the line from OB to pocket will also move maintaining the 30 degree angle. The ball will still go in the pocket but not on the same path as shown above. Or am I not seeing something?

Jake

Bob_Jewett
01-10-2005, 04:01 PM
<blockquote><font class="small">Quote Cane:</font><hr> /ccboard/images/graemlins/smile.gif No, Bob, I haven't forgotten my high school geometry, or College Calc or Physics or Engineering Physics, and it requires a good knowledge of all of these to do the work I did in an attempt to disprove this aiming method.
... <hr /></blockquote>
Sorry, I'm not convinced of this yet. I believe that there is a one-to-one correspondence between fullness of hit and angle of cut. I believe that correspondence (without including throw) is shown by the plot in the PDF file http://www.sfbilliards.com/fract.pdf

First: do you believe that there is a one-to-one correspondence between fullness of hit and cut angle? If you aim to hit more of the ball, do you get less cut?

Second: what would your plot of the relationship look like if it is different from the plot above?

Qtec
01-10-2005, 07:42 PM
START(
%A`6T1%BL7P8%CJ5O4%DL7N1%EK4X2%FK6P1%GK6N8%HM7N8%I L7O4%JK6M5
%KJ5P7%LJ5N2%ML4W4%NJ5R0%OJ5M0%Pr7R5%Qr0P8%Rq9M5%S E0C6%U]2U5
%Vr7R1%WY0X2%Xq7N2%]D2D3%^c8U8
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wei (http://endeavor.med.nyu.edu/%7Ewei/pool/pooltable2.html)

Is this what you are saying?

" The shot to pocket C is a HB cut from point A. If I move the QB to point B and still aim HB, I will still make the shot?"

I dont see it working.
Have you tried this on a snooker table?

Qtec

Bob_Jewett
01-10-2005, 08:31 PM
<blockquote><font class="small">Quote Cane:</font><hr> ... One way I demonstrate this is by showing someone the ghost ball method. I'll set up a long shot not exactly 30°, but somewhere in the neighborhood of 30°to 35° and literally put a real ball against the object ball so that it would be an "on shot", have them line up to hit the ghost ball full, then before they shoot, remove the ghost ball and ask them where the center of the cue ball is pointed. They'll inevitably say "Well, right at the edge of the object ball." Then I'll move the cue ball 6 inches or so to the right or left, to make the cut a little tougher angle, line up a ball in place of the ghost ball again, and have them line up to hit it full, remove the ghost ball and again, they see that the cue ball's center line is lined up EXACTLY with the outside edge of the object ball. ... <hr /></blockquote>
If that's what they say, I guess they are lousy observers. A 35-degree cut requires a 0.43 fullness hit -- your stick must be pointed outside the object ball. For a 25-degree cut, it's about 0.57 fullness, or with the cue stick pointed somewhat inside the object ball. Neither is 0.50 (at the edge).

A drawing of this is available as a very small PDF at http://www.sfbilliards.com/cuts.pdf

GeraldG
01-10-2005, 08:41 PM

I played a little with this in practice last night, and I had a match today and during practice I played around with it a little more. I didn't have much time and I don't fully understand it yet, but from what I little I saw, there may be something to this.

I need to understand it a little better, though...so I can work out an approach to learning how to use it.

<hr /></blockquote>
Cane,

I'm obviously doing something wrong here, or looking at something from the wrong perspective.

Now that I have paid attention to it, I DO notice that a lot of the shots that come up require a half-ball hit (or something very close to it).

However, if I set up a shot that requires a half-ball hit for the OB to go center-pocket, then move the cueball left or right perpindicular to it's line to the CB, I will still hit the pocket for small moves of the cueball (maybe two or three inches). But, the OB does not still follow the exact same path to the pocket. The reason that I still hit the pocket on small moves of the CB is because of the width of the pocket. I have to make some adjustment to stay center-pocket, resulting in something other than a true center-ball hit.

I haven't tried playing with the other 5 OB contact points you talked about (haven't gotten past the first one). I placed an imaginary clock on the table with the OB representing the center of the clock (the pivot point for the hands), the middle diamond between the corner pocket and the side pocket being the 12:00 position. If I start out with a half ball hit and move the cue ball around the object ball (as in following a clock), the contact point at the pocket or cushion is commensurate with the move of the cueball. For instance, If I start with the CB at the 6 o'clock position, point where the OB contacts the cushion (or pocket) will be in the 10:30 position or so for a half-ball left-hand cut. If I move the CB to the 8:00 position, the contact point on the cushion will be at the 12:30 position or so. (the numbers I'm using here are approximations, for the purpose of illustrating my point only)

What am I doing wrong here, or what am I looking at wrong? The results I get were EXACTLY what I expected, but not what I was looking for (if that makes sense). According to what I got from your writing, I should have see the OB take the exact same path to the pocket as I moved the CB in an orbit around the OB, up to 30 degrees or so. What I saw was the OB still going into the pocket for that 30 degrees approximate range of orbit, but following a slightly different path each time corresponding exactly to the amount the CB was moved.

What am I doing wrong here? I HAVE gotten something that may be useful ot of this so far...I now can quantify on longer shots which shots will work with a half-ball shot because I was forced during this experiment pay attention to the range of angles a half-ball shot will work with. Previously, I knew that a spot shot with the CB a few inches off the rail on the opposite string was a half-ball shot, but if it was more than a couple of inches off the spot, I had to go and find the contact point. Now I can just look at the angle of divergence of the object ball to the pocket from the line of a full-ball hit and pretty accurately tell if a half ball hit will pocket the ball.

I would have PM'ed you with this, but I figured that some other forum members might be working on this and maybe coming up with the same results and could also benefit from your answers.

Bob_Jewett
01-12-2005, 12:29 PM
<blockquote><font class="small">Quote GeraldG:</font><hr>... I'm obviously doing something wrong here, or looking at something from the wrong perspective.... <hr /></blockquote>
Did my drawing of 25-30-35 degree shots help?

GeraldG
01-12-2005, 02:55 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> <blockquote><font class="small">Quote GeraldG:</font><hr>... I'm obviously doing something wrong here, or looking at something from the wrong perspective.... <hr /></blockquote>
Did my drawing of 25-30-35 degree shots help? <hr /></blockquote>

Bob,
Yeah, but that's not really what was giving me trouble. I'm trying to make Cane's method work for me and it just ain't happening.

Cane was kind enough to email me some details that should have been sufficient to make it clear to a complete idiot. For whatever reason, it just doesn't work out for me.

If I set up a shot that requires a half-ball hit (about a 30 degree cut), a half ball hit will, of course, pocket the ball. According to what Cane sent me, I should be able to use that same half-ball hit to pocket balls with up to about 40 degrees or so of cut angle. So, if I move the cueball around so that I have a cut of something close to 40 degrees (between 35 and 40 degrees), and carefully make that same half-ball hit, I miss the pocket every time. When I first started playing around with it, I thought that there might actually be something to it (and there may very well be....it could be ME that's not working as advertised). What I found was the depending on how far the OB was from the pocket, I could use a half ball hit and pocket balls from a little less than 30 degrees to a little more than 30 degrees cut angle. My guess is about 29 deg to about 32 deg if it was close to the pocket, less if it was further from the pocket. This was due to the natural margin of error because the pocket is wider than the OB.

What I'm finding out in my case is that the six contact points Cane talks about will, in fact, pocket many of the shots on the table, but if on a 9-foot table you try them at more than half table length, adjustments have to be made. I cannot get a half-ball hit to pocket a ball at a 35 degree cut angle from half table-length. If the OB is a foot away from the pocket it might work, but any further than that and I have problems with it.

Cane is convinced that this method works, and seems to have a list of other people that I hold in fairly high esteem that are also apparently just as convinced. It's frustrating to me that I can't seem to make sense of it. I have no problems with my old aiming system, but this idea was intriguing to me.

Part of what I read of this method states that every object ball on the table will lie on one of several specific angles to the pocket, 0,15,30,45,66.5, etc. degrees. This part really confuses me. I know I can place a cueball on the table at, say, 20 degrees from the center of the pocket. This makes me think that the stated angles are taking into account the width of the pockets, but the text says that the OB will travel to the exact center of the pocket every time.

It's just very confusing for me. I'm obviously still missing some key point here with this method. I played around with it for 3 hours Sunday night and couldn't get it to work out the way I read the explanation, and I had many balls that did not appear to be on one of the exact angles that were specified.

I know that Cane knows what he's talking about because he's a BCA Certified Billiards instructor. The stuff he sent me looks like a lot of work and time went into it. It obviously works for him (and other people), so why doesn't it work for me?

Unfortunately, I had to undergo some surgery on Monday morning, so it's going to be a few days before I can try this again. But Cane has offered to assist me with it over the phone, too. He's really going out of his way to get the point across to me and I feel bad that I'm so thick that I just can't seem to get it.

I'm going to take a straight-edge and a protractor to the pool room with me and try to find out exactly what is up as soon as I'm able to.

I don't have any problem pocketing balls with my old system (most of the time), but it does frequently require me to walk to the other end of the table, find the exact contact point on the OB, walk back to the cueball end of the table, find the line to the OB, etc. If this system works for me, then it will eliminate having to walk back and forth because all I have to do is estimate the angle to the pocket and use one of six prescribed hits.

Of course, the other possibility is that I will screw my game up beyond all recognition trying to change systems. /ccboard/images/graemlins/smile.gif

cheesemouse
01-12-2005, 03:04 PM
[ QUOTE ]
Of course, the other possibility is that I will screw my game up beyond all recognition trying to change systems.

<hr /></blockquote>

<font color="red"> BINGO!!! </font color>

Bob_Jewett
01-12-2005, 05:15 PM
<blockquote><font class="small">Quote GeraldG:</font><hr> ... I should be able to use that same half-ball hit to pocket balls with up to about 40 degrees or so of cut angle.... <hr /></blockquote>
Geometrically, this is complete nonesense. As shown on the plot referenced before, you need a 0.35-full hit for a 40-degree cut. (Actually, if you include a little throw, the hit needs to be a little thinner than that.) You will get a 40-degree cut for a half-ball aim only if you aim very badly. Or at least strangely.

And, if you don't believe the plot, its easy enough to make a careful drawing of a 40-degree cut and see how far outside the object ball the path of the cue ball must point. If you would like, I can add that line to the plot I already posted, but I can already tell you the answer: the path will be very close to (but not exactly) twice as far outside the object ball as for the 35-degree cut.

GeraldG
01-12-2005, 06:05 PM
<blockquote><font class="small">Quote Bob_Jewett:</font><hr> <blockquote><font class="small">Quote GeraldG:</font><hr> ... I should be able to use that same half-ball hit to pocket balls with up to about 40 degrees or so of cut angle.... <hr /></blockquote>
Geometrically, this is complete nonesense. As shown on the plot referenced before, you need a 0.35-full hit for a 40-degree cut. (Actually, if you include a little throw, the hit needs to be a little thinner than that.) You will get a 40-degree cut for a half-ball aim only if you aim very badly. Or at least strangely.

And, if you don't believe the plot, its easy enough to make a careful drawing of a 40-degree cut and see how far outside the object ball the path of the cue ball must point. If you would like, I can add that line to the plot I already posted, but I can already tell you the answer: the path will be very close to (but not exactly) twice as far outside the object ball as for the 35-degree cut. <hr /></blockquote>

Yep, that's what I thought I knew and what was intuitive to me. And...that is what is being proved out on the pool table. But it certainly doesn't agree with what Cane sent me. He seems so certain of what he's saying....why doesn't it make sense to me? He's teaching this method and he's using it successfully and apparently his students are too. Am I in the twilight zone?

Bob_Jewett
01-12-2005, 06:32 PM
<blockquote><font class="small">Quote GeraldG:</font><hr>... He's teaching this method and he's using it successfully and apparently his students are too. Am I in the twilight zone? <hr /></blockquote>
I think that to play successfully, you have to eventually stop playing by any real system and aim by feel. Perhaps "half ball fits all" -- yes, I'm aware that "all" is an overstatement -- is a way to encourage the student to stop thinking analytically with the result that they have to go on feel.

SPetty
01-13-2005, 09:32 AM
<blockquote><font class="small">Quote GeraldG:</font><hr> He seems so certain of what he's saying....why doesn't it make sense to me? He's teaching this method and he's using it successfully and apparently his students are too. Am I in the twilight zone? <hr /></blockquote>Howdy GeraldG,

I'm in the same zone as you. I want to believe, and I try to believe, but it just doesn't seem to make sense. Also, if it was logical or supported by physics, I think the explanation could be made so that we could understand it.

One point you missed in your previous well written post is that those who are trying to show you this aiming method will also say that if you missed pocketing the ball, it must have been something wrong with your stroke, not the aiming method! /ccboard/images/graemlins/confused.gif /ccboard/images/graemlins/confused.gif

highsea
01-13-2005, 06:59 PM
<blockquote><font class="small">Quote DennyS:</font><hr> http://img.photobucket.com/albums/v201/DStewart1/Exampleof30degorhalfballshot.jpg<hr /></blockquote>Well, it seems pretty obvious to me that moving the CB is going to move the aim line. Picture the center of ghost ball as the pivot point of the aim line. If you move the CB, the aim line on the other side of the ghost ball has to move away from, or into the object ball (depending on which way you move the cue ball). So clearly the half ball hit only applies to the position of the balls as drawn.

Qtec
01-13-2005, 07:32 PM
Consider this.

If a straight shot is 0 degrees and an as thin as possible cut shot is 89 degrees, that gives 90 different contact points. The width of half a pool ball is 28.5 mm. To hit exact degree points you would have to be able to aim to an accuracy of roughly a third of a mm and even less than that for thinner cuts.
You need sharp eyes /ccboard/images/graemlins/laugh.gif to be able to split mm,s at any distance!

Q

Bob_Jewett
01-13-2005, 08:18 PM
<blockquote><font class="small">Quote Qtec:</font><hr> Consider this.

If a straight shot is 0 degrees and an as thin as possible cut shot is 89 degrees, that gives 90 different contact points. The width of half a pool ball is 28.5 mm. To hit exact degree points you would have to be able to aim to an accuracy of roughly a third of a mm and even less than that for thinner cuts.
You need sharp eyes /ccboard/images/graemlins/laugh.gif to be able to split mm,s at any distance! <hr /></blockquote>
And the amazing thing is that people can not only play, but play well. If you've ever seen a champion fire balls in on a 6x12 snooker table, you begin to be impressed by how accurately some people can sight and move their arms.

Rod
01-13-2005, 09:10 PM
[ QUOTE ]
The width of half a pool ball is 28.5 mm. To hit exact degree points you would have to be able to aim to an accuracy of roughly a third of a mm and even less than that for thinner cuts.
<hr /></blockquote>

What's that in inches? LOL Really a millimeter is roughly .0394 of an inch. If a shaft is 12.75 mm it is short .010 of being 13mm. Not a big deal but some people make a big deal of it all. The shaft is to big etc. That is .005 of an inch a side. If you ask someone how thick is a match book, they don't know. ( apx .014 to .015.) Not suprising but your aim at a pool ball may have to be as accurate. Wich is less than a third of a mm.

Seeing the difference is critical on pool shots but it isn't necessary to know the actual difference. When I was younger I could see a hair on a ball at distance, appx .006 if you will. I know from automotive and machine work but it is amazing how fine aim has to be at times.

Rod

Qtec
01-13-2005, 09:43 PM
[ QUOTE ]
And the amazing thing is that people can not only play, but play well. <hr /></blockquote>
After calculating the squirt, throw and SIT, its a wonder that anyone can run 3 balls. /ccboard/images/graemlins/grin.gif

paulfr
01-20-2005, 01:33 AM
When I first read this thread, I thought Cane was a troll for sure. He certainly baited everyone to attention.
But I will take the several posters' word that he is sincere in his theory and reported success.
I like Bob's explanation that it is really a psychological method not a scientific method.
Anyway, I decided to look up Koehler's accuracy tables and for pocket-OB and OB-CB distances of one diamond the errors can be as high as 10%. This is intuitive in the extreme as a ball 1 inch from the pocket can be hit almost anywhere including half ball and go in.
But this theory/method simply cannot hold up for a 4 diamond/4 diamond shot. Koehler's numbers show with cut angle correction (page 48), a 30 degree cut requires better than 0.16 degrees of permissible error. This is 0.16/30 = .00533 or about one half of one percent. Six points of aim cannot be this precise. Either Koehler is wrong or Cane is wrong for large distances.

So in summary, this theory/method does work for balls close to the pocket (one to two diamonds) assuming you ignor Cane's assertion that his balls go center pocket.
And since most shots for most games have the object ball not more than 2 diamonds from a pocket, it would appear this method applies most of the time as he said.

But it will not work for longer distances. Not six points of aim anyway.

Alfie
01-20-2005, 04:18 PM
<blockquote><font class="small">Quote paulfr:</font><hr> When I first read this thread, I thought Cane was a troll for sure. He certainly baited everyone to attention.
But I will take the several posters' word that he is sincere in his theory and reported success.
I like Bob's explanation that it is really a psychological method not a scientific method.<hr /></blockquote>

This is not a new controversy. The adjustments from a reference point can be slight and subtle. Many are not aware they make these adjustsments and will even swear they don't. But, like Scott L. said in another thread recently, "you can't argue with physics." So if one maintains that things fall up or "there are only three angles in pool" (or some such) others will tend to look askance at them.

IMO

dr_dave
01-21-2005, 10:39 AM
<blockquote><font class="small">Quote paulfr:</font><hr>for a 4 diamond/4 diamond shot. Koehler's numbers show with cut angle correction (page 48), a 30 degree cut requires better than 0.16 degrees of permissible error. This is 0.16/30 = .00533 or about one half of one percent. Six points of aim cannot be this precise. Either Koehler is wrong or Cane is wrong for large distances.<hr /></blockquote>
FYI, the diagrams in my Jan '05 instructional article (http://www.engr.colostate.edu/~dga/pool/bd_articles/jan05.pdf) show the permissible object ball angle errors for side and corner pockets at slow and fast speeds, and the plots in TP 3.4 (http://www.engr.colostate.edu/~dga/pool/technical_proofs/TP_3-4.pdf) show how object angle errors depend on cue ball distance and cut angle.

For a slow, 30-degree cut angle, straight-in shot into a corner pocket on a 9' table, with 4 diamonds (approximately 4.5') between the CB and OB and 4 diamonds between the object ball and the pocket, assuming BCA spec pockets, the allowable OB error is approximately 2 degrees (see Diagram 2 in the article (http://www.engr.colostate.edu/~dga/pool/bd_articles/jan05.pdf)) and the corresponding allowable cue ball error is about 0.07 degrees (see the example I've added to the bottom of TP 3.4 (http://www.engr.colostate.edu/~dga/pool/technical_proofs/TP_3-4.pdf).

HALHOULE
03-15-2006, 05:07 AM
You are talking contact points. Contact ponts are totally invisible. That is only one of your many problems. A very simple method of pocketing balls has no need of contact points on any shot.

Scott Lee
03-15-2006, 08:05 AM
Hal...Do you realize that almost all of your posts are posted on threads that are 1-3 yrs old? If you post on more current things, you might get some response. It sure seems like all you do, is search the archives for old threads, where you can post something dirogatory. Why is that? You have so much to offer the pool world...why spend your time this way?

Scott Lee

Keith Talent
03-15-2006, 09:36 AM
Whew! Thanks for pointing that out, Scott. I was about to add some ignorant comments to that fresh debate.

Still, I found it interesting where Bob Jewett said, er, last year, after all the aiming mumbo-jumbo, that it finally comes down to feel if you're going to be successful, lol.