*** Thin Ball Aiming System-inside of object ball ***

[3kushn]

Sorry double post for some darn reason

 

[framedglasshadd]

framedglasshadd, It was difficult to follow the math since I'm not a math wizard but it appears your reference material isn't exactly appropriate for this discussion. I say that with all due respect. Although not the math wizard I am well versed in Torque. It’s my business profession. The formula stated Torque = Force * Radius is what leads me to the conclusion. Torque = Force * Length. Its a fine point for argument but there's only one radius to a circle and we can never cue at THE radius. Your response can be, we can define several circles from center, each with a radius. That's fine, but not mentioned.

The main argument that’s not addressed is the belief that no matter what, the ball is gone within approx 1/10,000 second after cueing. Therefore pushing is not possible. Soft tip vs Hard tip has been studied too and some increased time but little. Now we have to argue, is there a significant difference if tip contact time makes a difference if its 1/10,000 second vs 1/9,000 second. Maybe. Not aware of any study on this.

Lastly a surprise. FOR ME IT SEEMS. If I choke up on the cue with a short stroke I definitely produce more English, period. Don't know why but I can and use this a few times per game.

Oh I am sorry if it was not clear..... I meant greater radius as in, instead of hitting 1 tip of english, you hit 2 tips. 2 tips will give you 'more' english.

And forgive me for forgetting the original question as well... Using a long stroke means the cue tip's time in contact with the cb is significantly longer. To the original question, as Bill replied, it is absolutely not true. If you picture it in slow motion, the ball is in contact with the tip throughout the stroke until you stop moving your cue. When you hit the cue ball, you are making it accelerate at the rate of you cue. However, friction is slowing the cue ball down. It is not possible for the cue ball to escape your cue... it is certainly NOT faster than your cue (unless you decelerate your cue). This is because, at rest, there is no force acting in the horizontal direction, assuming a completely flat table. Gravity pulls it down and the normal force (exerted by the table) pushes up for the vertical direction. If the table did not push up, the ball would fall through the table. However, these forces are equal and in opposite directions. The net force in the vertical and horizontal direction is 0. This is why the ball does not move by itself. Then comes your cue. The only other horizontal force (ignoring all air resistance in this scenario) is friction on the ball pushing opposite the motion. The cue keeps going forward until you stop it OR slow down, no friction from the table on the cue. Without any other force to push the ball in this direction, it cannot be faster than the cue. It would not make sense for something on a flat, horizontal surface to move faster than what pushed it (assuming no other force pushes that direction) and especially because the pushed object has friction slowing it down. Bringing this to a next point...

Why doesn't the cue ball stop when you stop pushing it then? Momentum... Like when you push a shopping cart. Even when you stop pushing, it will continue to roll forward for a while. You have stopped the cue's movement with your hand/arm but did not stop the ball. You will have to slow the cue to a stop at some point, and that is the point where the ball will "leave" the influence of your cue, NOT at the instant of contact because your cue is still going forward with the ball and it is what gave the ball its initial speed to begin with... Thus the cue is in contact with the cue ball the whole time during the stroke, unless you stop or slow down your cue (to a rate slower than the cue ball) making a long stroke distinct from a short stroke.

A small difference in amount of time (or rather, distance) the cue is in contact makes a bigger difference if there is more force. Don't know if that answers anyhing, but it does make sense...

I have no idea why a short stroke would result in more english, but billiards is a mysterious game and works differently for everyone, I guess. Anyway, I hope that better answers the question... I am not a very experienced player myself, so mercy on me if my pencil-and-paper reasoning is no good. I jump for joy when I run 2 and when I make the break... :grin:

 

[3kushn]

Just a question. Do you think there's no deceleration of the cue when it meets the ball?

Go down a little over half way on this page for slow mo vids with various tip hardness and cue speeds. You will see the cue ball leaves the tip pretty quickly no matter what speed. But there is a difference mostly due to tip compression. I think.
http://billiards.colostate.edu/high_speed_videos/index.html

 

[Bob Jewett]

Just a question. Do you think there's no deceleration of the cue when it meets the ball?

Go down a little over half way on this page for slow mo vids with various tip hardness and cue speeds. You will see the cue ball leaves the tip pretty quickly no matter what speed. But there is a difference mostly due to tip compression. I think.
http://billiards.colostate.edu/high_speed_videos/index.html

The high-speed videos have shown (and simple physics predicts) that when the tip hits the ball, the cue stick slows almost immediately to 50% of the speed it had just before impact. At the same time, the cue ball is accelerated by the force of the tip to about 130% of the speed of that the cue stick had just before impact. That means that if the cue stick goes into the shot at 10MPH, it slows down in about 0.001 seconds to 5MPH and at the end of the 0.001 second contact, the cue ball leaves the tip at 13MPH.

Some of this is quite old news. In 1941/42 Professor A.D. Moore, in his remarkable study of Willie Hoppe's stroke, measured the 130% number. If the tip is perfect, the ball speed is expected to be 150% for a center-ball hit, but the tip (and the stick) dissipates some of the energy.

What is somewhat new is the actual measurement of both the nearly instantaneous slowing of the cue stick during the tip-ball collision and the relatively gradual increase in stick speed after the collision due to the hand following through and dragging the stick back up to speed.

 

[Bob Jewett]

... Conceptually, it is the change in momentum. Thus if the tip is in contact with the for a longer time, the more impulse (change in momentum) is created. ...

This is false. The change in momentum is the integral of force with respect to time. The same momentum is transferred with a short contact and high force or a long contact and low force.

The relationship between the stick speed and the ball speed is almost unrelated to the hardness of the tip which is the primary influence on how long the tip-ball contact lasts. If you have a hard tip, the contact will be shorter but the force correspondingly larger. If the tip is soft, the contact will be longer but the force smaller. In the end, the ball speed is the same if the tips are of the same quality and is determined solely by the speed of the stick at the moment of impact.

The grip and the follow through have almost nothing to do with how long the tip is on the ball.

In addition, there is a good reason why you don't want to prolong the tip-ball contact time. If the tip stays on the ball too long, a miscue is guaranteed.

 

[Bob Jewett]

Bob; you are the all inclusive skeptic, but, I do have an example of 2 shots I demonstrate in clinics and exhibitions.
...

Hi Bill,
The one with right english I think I understand, but I want to make sure I understand the shot with left english. You show it being shot from the same position and that position for left english will require the cue stick to be passing over where the two cushions meet. Is that the shot with left english? I ask because the difficulty of the shot depends critically on how near the end rail the cue ball is.

You may want to change the the lower-left ball overlap diagram as it shows the cue ball hitting the wrong side of the object ball for the shot diagram.

 

[mr3cushion]

Hi Bill,
The one with right english I think I understand, but I want to make sure I understand the shot with left english. You show it being shot from the same position and that position for left english will require the cue stick to be passing over where the two cushions meet. Is that the shot with left english? I ask because the difficulty of the shot depends critically on how near the end rail the cue ball is.

You may want to change the the lower-left ball overlap diagram as it shows the cue ball hitting the wrong side of the object ball for the shot diagram.

Bob, Bob, Both the table diagram and cue ball and object ball diagrams are TOTALY CORRECT!!!!!

Bill Smith "Mr3Cushion"

 

[Bob Jewett]

.. Both the table diagram and cue ball and object ball diagrams are TOTALY CORRECT!!!!! ...

The ball diagram on the bottom left of your image shows the cue ball hitting the object ball on the right side. Is that what you want it to show? This is the sub-diagram I mean:

 

[mr3cushion]

The ball diagram on the bottom left of your image shows the cue ball hitting the object ball on the right side. Is that what you want it to show? This is the sub-diagram I mean:
View attachment 243810

Bob; I appologize, the cue ball solid line diagram was INCORRECT, I have corrected it!

Thanks;
Bill Smith "Mr3Cushion"

 

[Slh]

Bob Jewett:

you are basically saying no matter how you grip the cue, the amount of acceleration is always the same?
I always knew that a loose grip is essential in order to accelerate through the cueball more and smoothly.
I remember my first period of playing pool I had troubles drawing the cueball because I was gripping the cueball too tightly, this leads to less acceleration.
This is the difference beetween the two strokes ( in my mind, I could be wrong):
-long stroke: smooth stroke through the cueball = more acceleration
-short stroke: punchy stroke with less acceleration.
The amount of acceleration change the way the cueball reacts.

 

[mr3cushion]

:dance:

Since this topic is one of the most interesting one created while ago!!!
I have to answer it.

I just came back from the ELKS lodge in Burbank. tried the Smith techique!
It works very well , the first diagram took me 2 tries and the second diagram took me 5 to 6 tries and after that , I was able to make it 80 % (very good for me ).

I did learn the game in Europe at a younger age and I learned it the same way as Rogi conti Taught the rest of the world how to implement 5 strokes ....
But since I came to the state , I decided to learn the techinque from a pool instructor (scott lee) he is truly gentleman and a great instructor! I tried the techique for a month (3 cushion ) playing with the same stroke (follow though) , unfortunately it dosen't work for 3 cushion all the time , specially in cases like Bill showed .

I tried both ways and believe the 5 stroke technique is the ONLY and The most EFFECTIVE way in 3 cushion to achieve a higher average and better game .

enjoy the Roger Conti and straight rail billiards film

http://www.poolchat.net/forums/index.php?showtopic=8418

Fox; Thanks for the POSITIVE post, maybe this will reassure me that I hadn't lost my mind, yet!

Bill Smith "Mr3Cushion"
http://mr3cushion.com

 

[Bob Jewett]

Bob Jewett:

you are basically saying no matter how you grip the cue, the amount of acceleration is always the same?
I always knew that a loose grip is essential in order to accelerate through the cueball more and smoothly.
I remember my first period of playing pool I had troubles drawing the cueball because I was gripping the cueball too tightly, this leads to less acceleration.
This is the difference beetween the two strokes ( in my mind, I could be wrong):
-long stroke: smooth stroke through the cueball = more acceleration
-short stroke: punchy stroke with less acceleration.
The amount of acceleration change the way the cueball reacts.

How you grip the cue will determine how easily you can get the cue stick up to speed and following a straight path. I'm saying that both the theory and video show that the grip you have at the instant of tip-to-ball contact is not important. If a millisecond before contact someone fired a high-power laser and removed your hand at the wrist, the shot would not notice the difference, assuming the blood spatter was minimal.

Your stroke is a preparation for impact. It has no effect at the instant of impact. If you have not prepared properly, no last-millisecond adjustment or acceleration can help.

Acceleration gets the stick up to speed, by definition. It is the speed that does the work. Acceleration at the moment of impact is irrelevant. Smooth acceleration is likely to deliver the cue stick in a much more consistent way, but it is not by itself required for good play. See Allen Hopkins as a counter example. Acceleration has a very specific meaning; most casual readers do not understand that meaning: change of velocity per unit time.

 

[framedglasshadd]

This is false. The change in momentum is the integral of force with respect to time. The same momentum is transferred with a short contact and high force or a long contact and low force.

The relationship between the stick speed and the ball speed is almost unrelated to the hardness of the tip which is the primary influence on how long the tip-ball contact lasts. If you have a hard tip, the contact will be shorter but the force correspondingly larger. If the tip is soft, the contact will be longer but the force smaller. In the end, the ball speed is the same if the tips are of the same quality and is determined solely by the speed of the stick at the moment of impact.

The grip and the follow through have almost nothing to do with how long the tip is on the ball.

In addition, there is a good reason why you don't want to prolong the tip-ball contact time. If the tip stays on the ball too long, a miscue is guaranteed.

Yes, I said that change in momentum is impulse, which is the integral of force with respect to time in the post... using a definite integral, you would say it is from the initial time to the final time. It is correct that a low contact time and high force will yield the same impulse as a long contact time and a smaller amount of force as long as the area beneath the curve (when graphed) is the same. I assumed the force was constant, however, so a longer contact time would be beneficial. Short stroke+high force and Long stroke+low force are options, but not the only options. If you hit with a certain force, high or low, it would give more impulse if it is over a greater amount of time unless the force becomes zero (then there would be no area under the curve, and thus no impulse); a low force over a greater amount of time is still more impulse than a low force over a lesser amount of time.

The follow-through, if it is long, the cue is touching the cue ball for a longer amount of time, unless you can push it out in the same amount of time as a short stroke. The horizontal forces exerted on the cue at the moment of contact are the force you are giving it and the contact force (from the ball on the cue). The contact force is what pushes the cb in the direction you hit. I'm sorry I was technically incorrect because the force you exert is on the cue, not on the ball itself. The cue ball's movement, then is due to contact force which cannot be greater than the force you exerted on the cue. Recalling that the cue goes it the direction you push it and not in the opposite direction (from the contact force), the force you use to push must be greater to yield a net force and thus acceleration in that direction... So what I am trying to say is:
The contact force of the cue on the ball and the ball on the cue are the same magnitude (but in opposite directions).
->Your force on the cue is greater than contact force and thus you are able to accelerate the cue forward.
-->Contact force is what pushes the ball forward.
--->The ball cannot have a greater acceleration, unless the mass of the cue is large enough to require more force to attain a greater acceleration.

At the if the moment of impact is prolonged, acceleration would matter... the ball and cue are accelerating as a system. Accelerating the cue would accelerate the ball as long as they are still in contact. It is not sensible, however, to push the ball for so long that your chalk wears away or you lose balance from not being able to extend your arm out so long.

I also apologize for not taking in the nature of the tip... I was not thinking practically. I do not even have my own cue and for now it doesn't seem to matter too much when I practice. As I mentioned before, I am not a very experienced player... my stroke is usually more like pushing the ball rather than striking it. To compensate for the force pushing back (which will inevitably slow the cue down), I think one would naturally accelerate the cue (all throughout the stroke, especially at moment of contact), pushing harder all the way until satisfied with the length of the stroke (and then slow it to a stop). If not, the cue would appear to move a lot slower after the contact, which may be how it's supposed to be, I don't know.

It is not my place to say, but if you knew the answer and/or proof already... you should have said it... would have saved a lot of trouble.

 

[Slh]

Yes, I said that change in momentum is impulse, which is the integral of force with respect to time in the post... using a definite integral, you would say it is from the initial time to the final time. It is correct that a low contact time and high force will yield the same impulse as a long contact time and a smaller amount of force as long as the area beneath the curve (when graphed) is the same. I assumed the force was constant, however, so a longer contact time would be beneficial. Short stroke+high force and Long stroke+low force are options, but not the only options. If you hit with a certain force, high or low, it would give more impulse if it is over a greater amount of time unless the force becomes zero (then there would be no area under the curve, and thus no impulse); a low force over a greater amount of time is still more impulse than a low force over a lesser amount of time.

The follow-through, if it is long, the cue is touching the cue ball for a longer amount of time, unless you can push it out in the same amount of time as a short stroke. The horizontal forces exerted on the cue at the moment of contact are the force you are giving it and the contact force (from the ball on the cue). The contact force is what pushes the cb in the direction you hit. I'm sorry I was technically incorrect because the force you exert is on the cue, not on the ball itself. The cue ball's movement, then is due to contact force which cannot be greater than the force you exerted on the cue. Recalling that the cue goes it the direction you push it and not in the opposite direction (from the contact force), the force you use to push must be greater to yield a net force and thus acceleration in that direction... So what I am trying to say is:
The contact force of the cue on the ball and the ball on the cue are the same magnitude (but in opposite directions).
->Your force on the cue is greater than contact force and thus you are able to accelerate the cue forward.
-->Contact force is what pushes the ball forward.
--->The ball cannot have a greater acceleration, unless the mass of the cue is large enough to require more force to attain a greater acceleration.

At the if the moment of impact is prolonged, acceleration would matter... the ball and cue are accelerating as a system. Accelerating the cue would accelerate the ball as long as they are still in contact. It is not sensible, however, to push the ball for so long that your chalk wears away or you lose balance from not being able to extend your arm out so long.

I also apologize for not taking in the nature of the tip... I was not thinking practically. I do not even have my own cue and for now it doesn't seem to matter too much when I practice. As I mentioned before, I am not a very experienced player... my stroke is usually more like pushing the ball rather than striking it. To compensate for the force pushing back (which will inevitably slow the cue down), I think one would naturally accelerate the cue (all throughout the stroke, especially at moment of contact), pushing harder all the way until satisfied with the length of the stroke (and then slow it to a stop). If not, the cue would appear to move a lot slower after the contact, which may be how it's supposed to be, I don't know.

It is not my place to say, but if you knew the answer and/or proof already... you should have said it... would have saved a lot of trouble.

It's proven that the tip of the cue is in contact with the cueball for 0,001 sec even during breaks ( with 1 foot of followthrough).

 

[framedglasshadd]

It's proven that the tip of the cue is in contact with the cueball for 0,001 sec even during breaks ( with 1 foot of followthrough).

I am not saying it is wrong, but can you please explain how and why? Only a millisecond? No more, not even if your stroke is "slow"? Is this to say that the length of the stroke does not matter, or is one millisecond just an average of the amount of contact time?... How was it proven? I'm sorry for so many questions but I am really curious now; I would really like to know because I just cannot imagine it. There may be something critical I overlooked when coming a conclusion.

I will still think length of stroke does matter... maybe I'm clinging but I just cannot think of how the cue ball can possibly be faster than the cue. Maybe on paper it is correct and there is some external variable I did not consider, such as tip hardness, that will affect the ball's speed relative to the cue enough to make the difference. Regardless, I still hold to my explanation for now.

And even if this is true (that length of stroke does not matter because contact time is the same every time, for the break or any other shot), though, I would like to understand how and why and perhaps I can improve my playing.

 

[Bob Jewett]

... maybe I'm clinging but I just cannot think of how the cue ball can possibly be faster than the cue. Maybe on paper it is correct and there is some external variable I did not consider, ...

I have explained the phenomenon in columns. You will find them here: http://www.sfbilliards.com/articles/BD_articles.html

There are lots of high-speed videos on Dr. Dave's site: http://billiards.colostate.edu/ that show what happens between tip and ball.

Basically, the reason that the cue ball can leave the tip faster than the stick was moving is that energy is stored in the tip, like a spring, and the ball is launched off the tip when the tip decompresses.

Both the theory (which is fairly simple as physics goes) and the measurements from high-speed video demonstrate that your assumptions about what happens during shots is completely wrong.

I think the best way for you to start to learn what is really happening is to watch some of the high-speed videos. Here is a very nice one to start with: http://www.youtube.com/watch?feature=player_embedded&v=avFjRgzTL-w and if you are really, really interested in learning about these things, I think you should get the DVD from which that clip comes. The shooter in the clip is Andreas Efler and that is his standard Moori tip you see deforming.

 

[Bob Jewett]

Bob; I appologize, the cue ball solid line diagram was INCORRECT, I have corrected it!

Thanks;
Bill Smith "Mr3Cushion"

Please also check my question about where the stick must line up for the shot with left english. I believe the diagram is wrong on that point as well.

 

[mr3cushion]

I think since this thread has turned out to be a "scientific witch hunt", the 3 "techno" players, Bob, Slh and Frammed should have a 3 man tounament, and live stream it!

Please keep score and innings, I think We'd all like to know how well all this "scientific mumbo-jumbo" works in a actual game setting, I at least would like to know. Also, on every shot, explain the "scientific" and "phyiscal" approach and "thought" process before attempting each shot!

What do you think guys?, good idea!

P.S. I'll donate a trophy, " United States Techno player of the Year"!

Respectfully;
Bill Smith "Mr3Cushion"

 

[Slh]

I think since this thread has turned out to be a "scientific witch hunt", the 3 "techno" players, Bob, Slh and Frammed should have a 3 man tounament, and live stream it!

Please keep score and innings, I think We'd all like to know how well all this "scientific mumbo-jumbo" works in a actual game setting, I at least would like to know. Also, on every shot, explain the "scientific" and "phyiscal" approach and "thought" process before attempting each shot!

What do you think guys?, good idea!

P.S. I'll donate a trophy, " United States Techno player of the Year"!

Respectfully;
Bill Smith "Mr3Cushion"

I'm sorry if you felt offended by my previous question. I didn't want to doubt your knowledge of the game, I just ask a question about this controversial subject. Somebody believes you can change how the cb reacts by using different strokes, others don't.
I don't have a precise position because I don't have enough knowledge in this subject.

 

[mr3cushion]

I'm sorry if you felt offended by my previous question. I didn't want to doubt your knowledge of the game, I just ask a question about this controversial subject. Somebody believes you can change how the cb reacts by using different strokes, others don't.
I don't have a precise position because I don't have enough knowledge in this subject.

It's not just about MY knowledge of the game, it's EVERY other TOP player in the World! All you have to do is REALLY watch videos of the BEST players in the World, don't just watch them scoring, but, HOW THEY SCORE a pont!

Once again Respectfully;
Bill Smith "Mr3Cushion"