Where is the Center of the Q Ball?

[nineballman]

There are some good posts here about where is the center of the Q ball. I started this thread because it was recently point out to me that I was consistently hitting the ball below center. This was causing me to hit harder than needed and possibly miss shots. Here are some thoughts I have.

1. The center of the Q Ball is NOT relative. The center is the core. No matter which direction you look at the Q Ball the core does not change.

2. What changes is the angle created by 2 lines. One running from the core through the point of contact with the tip. Another running from the point of contact and parallel to your point of aim. The wider this angle becomes the more spin you impart on the Q ball.

3. Center of the Q ball does not change in relation to the rails as some have said. The center is still the core!

4. When you must elevate your stick, yes the point of contact on the q ball does change but the center is the core.

Anyway, I now am aware of where I'm hitting the cue ball to a greater degree. I have also found that I can hit a lot further from center than I previously thought. This is helping me to move the cue ball and at the same time hit less hard and more accurate.

 

[Patrick Johnson]

1. The center of the Q Ball is NOT relative. The center is the core. No matter which direction you look at the Q Ball the core does not change.

Adding for clarity:

That's what I call the "3-dimensional center" or the "center of mass" (center of gravity), and I agree it doesn't change, and I think it's the "real" center that a player should use to produce follow, draw, etc.

But there's also a "2-dimensional center", which is what just about everybody thinks of when you say centerball: the place on the surface of the cue ball where the vertical and horizontal centerlines intersect (on the side the shooter is looking at). Most players think you have to hit above or below this "2-dimensional" centerpoint to get forward spin or backspin, but you really have to hit above or below the 3-dimensional center to get forward spin or backspin. This can be the same as "above or below the 2-dimensional centerpoint" (when your stick is nearly level), but it doesn't have to be the same.

2. What changes is the angle created by 2 lines. One running from the core through the point of contact with the tip. Another running from the point of contact and parallel to your point of aim. The wider this angle becomes the more spin you impart on the Q ball.

This is correct, but confusing. I think it's easier to simply think of where your cue stick is pointed (if you poked it straight through the cue ball). If it's pointed above the 3-dimensional center you'll produce forward spin. If it's pointed below the 3-dimensional center you'll produce back spin. Further above or below = more spin.

3. Center of the Q ball does not change in relation to the rails as some have said. The center is still the core!

This sounds to me like something a Houleigan might say (and should therefore be seasoned liberally).

4. When you must elevate your stick, yes the point of contact on the q ball does change but the center is the core.

This is another way of saying "aim above the 3-dimensional center for forward spin and below it for back spin". Note that I don't say "for follow" or "for draw" - these terms describe the spin that remains on the cue ball when it hits the object ball. "Forward spin" and "back spin" describe the spin that's on the cue ball immediately after you hit it - you might have to hit higher or lower to get follow or draw (depending on speed, distance and cloth/ball stickiness), but you'll still be aiming your stick above the 3-dimensional center for forward spin and below it for back spin.

Anyway, I now am aware of where I'm hitting the cue ball to a greater degree. I have also found that I can hit a lot further from center than I previously thought. This is helping me to move the cue ball and at the same time hit less hard and more accurate.

Hitting the cue ball precisely is VERY important, and simply being more aware of how you do it (and why, if you're so inclined) can produce a huge leap forward in your game.

pj
chgo

 

[Danny Harriman]

Go ahead and get one of those balls that is a 'training cue ball' when you see your chalk mark hitting the center of the cross haires you will think that you are hitting the center of the cue ball. This does not mean that you have stoked through the ball in an exact straight line, remember that depending on the forward weight distibution of your cue and or how soft the tip is means alot. The more length of time your tip stays on the cue ball the easier it is to spin the cue ball - therefore the more likely it is that any impurities in your stroke will show. Everybody likes to be an expert on this forum and I apalogize if I came on a little strong about my opinion being the only correct idea. I have seen many books on pocket billiards but none of which actually explained in detail on how to 'pot' a ball, I know more now about center ball than ever before. It's funny how when were in our youth we act out of instinct and as we get older we begin to think before we act. You must have the knowledge about every facet of the game as this can and will make you more experienced, but while being a student of the game you MUST learn to quite your mind.
Sincerely, Danny Harriman

 

[PoolSponge]

Here is my suggestion to find the center of the CB...

Take two object balls and put the frozen together. Place the CB on the other side of the balls frozen to the object balls. Now create a space in the object balls wide enough for your tip to barely pass. Place the tip of your cue in the gap created at the point where your ferrule will come as close as possible to the object balls, that is dead center from a flat stroke.

Funny enough, an empty beer bottle, when lying on its side, is almost exactly the same height as the CB. Practice stroking into the opening of the bottle without touching the sides of the bottle or the neck. That will help train your stroke to stay flat and straight as well as train your bridge hand to commit to memory where it needs to be at dead center.

JMO

 

[SpiderWebComm]

Go ahead and get one of those balls that is a 'training cue ball' when you see your chalk mark hitting the center of the cross haires you will think that you are hitting the center of the cue ball. This does not mean that you have stoked through the ball in an exact straight line, remember that depending on the forward weight distibution of your cue and or how soft the tip is means alot. The more length of time your tip stays on the cue ball the easier it is to spin the cue ball - therefore the more likely it is that any impurities in your stroke will show. Everybody likes to be an expert on this forum and I apalogize if I came on a little strong about my opinion being the only correct idea. I have seen many books on pocket billiards but none of which actually explained in detail on how to 'pot' a ball, I know more now about center ball than ever before. It's funny how when were in our youth we act out of instinct and as we get older we begin to think before we act. You must have the knowledge about every facet of the game as this can and will make you more experienced, but while being a student of the game you MUST learn to quite your mind.
Sincerely, Danny Harriman

Danny - check your messages, I sent you a PM. Thanks-
Dave

 

[Patrick Johnson]

The more length of time your tip stays on the cue ball the easier it is to spin the cue ball

I think this is one of those things that feels like it's true but isn't really. It feels like it's true because the way you change your stroke to try to keep your tip on the ball longer (say, hitting softer or stroking more smoothly or following through more) makes a real difference in the success of your shot - but it's not because your tip is actually staying on the ball longer or because you're "accelerating through" the ball or anything like that; it's really because you're hitting the cue ball more carefully and accurately.

I don't have any proof of this, but I've watched many high speed videos of tips hitting balls and it's pretty clear to me that there isn't much difference in contact time from one stroke to the next. The only thing that seems to make much difference is how far from center you hit.

However, I also think that any concept or method that helps you deliver an effective stroke is a good one, and if I thought it would give me a stroke like yours I'd change my mind right now. Hell, I'd trade my whole brain in.

pj
chgo

 

[crosseyedjoe]

I think this is one of those things that feels like it's true but isn't really. It feels like it's true because the way you change your stroke to try to keep your tip on the ball longer (say, hitting softer or stroking more smoothly or following through more) makes a real difference in the success of your shot - but it's not because your tip is actually staying on the ball longer or because you're "accelerating through" the ball or anything like that; it's really because you're hitting the cue ball more carefully and accurately.

I don't have any proof of this, but I've watched many high speed videos of tips hitting balls and it's pretty clear to me that there isn't much difference in contact time from one stroke to the next. The only thing that seems to make much difference is how far from center you hit.

However, I also think that any concept or method that helps you deliver an effective stroke is a good one, and if I thought it would give me a stroke like yours I'd change my mind right now. Hell, I'd trade my whole brain in.

pj
chgo

This is really puzzling. Ask anyone who knows how to use an old "whippy" Meucci and they will tell you that there is an observable effect of having slightly longer contact time. This is specially true with 9-ball which has bigger cue ball. Carom master and trick shot artist talk about "natural English."

Technicalist says otherwise because the contact time is too short to make a difference.

This leads me to believe that the big difference between me, you and great players like Efren Reyes and Mike Massey is the ability to "feel" this slight differences.

 

[Patrick Johnson]

This is really puzzling. Ask anyone who knows how to use an old "whippy" Meucci and they will tell you that there is an observable effect of having slightly longer contact time. This is specially true with 9-ball which has bigger cue ball. Carom master and trick shot artist talk about "natural English."

Technicalist says otherwise because the contact time is too short to make a difference.

This leads me to believe that the big difference between me, you and great players like Efren Reyes and Mike Massey is the ability to "feel" this slight differences.

It's pretty simple to test: hit a cue ball on the same spot (and at the same speed, etc.) many times using different sticks and strokes (whatever different strokes means to you), and measure the amount of spin you get each time. Have you or "anybody who knows how to use an old whippy Meucci" ever done that? It's the only way to move this question past the "I say, you say" level.

Without objective tests we can only speculate using logic and reason - what you say somebody else says they can feel is (obviously) not evidence. There's no purely logical/theoretical reason that what you say should be true, although I'm listening if you want to try.

By the way, I've done tests like I describe and could detect no difference in the amount of spin I can get using different sticks (including Meucci, although you might just say I didn't "know how to use it"). I didn't try different strokes because I don't know any (I don't think there are any).

pj
chgo

 

[crosseyedjoe]

It's pretty simple to test: hit a cue ball on the same spot (and at the same speed, etc.) many times using different sticks and strokes (whatever different strokes means to you), and measure the amount of spin you get each time. Have you or "anybody who knows how to use an old whippy Meucci" ever done that? It's the only way to move this question past the "I say, you say" level.

Without objective tests we can only speculate using logic and reason - what you say somebody else says they can feel is (obviously) not evidence. There's no purely logical/theoretical reason that what you say should be true, although I'm listening if you want to try.

By the way, I've done tests like I describe and could detect no difference in the amount of spin I can get using different sticks (including Meucci, although you might just say I didn't "know how to use it"). I didn't try different strokes because I don't know any (I don't think there are any).

pj
chgo

Fast Larry said if you want to move that cue ball around the table take out that old red-dot Meucci.

I understand your point-of-view because most techcalist says the same thing. But some players do experience the difference and that is what puzzling.

 

[JoeW]

Patrick Johnson said, "Without objective tests we can only speculate using logic and reason - what you say somebody else says they can feel is (obviously) not evidence. There's no purely logical/theoretical reason that what you say should be true, although I'm listening if you want to try."

While longer contact time may not be the issue, accuracy of the hit involves several issues and at least one can only be tested by a human.

A larger tip surface appropriately curved makes more contact with the cue ball.

A more flexible shaft has less force at contact: Some of the energy must be retained in the shaft. If the shaft bends, this will change the angle of hit on the cue ball. These slight changes are important when translated into the consistent accuracies needed to make various shots.

Most importantly, if a shorter back stroke and a longer follow through are used the point of contact and energy transfer are more likely to be on the intended line. This last point is quite important and needs to be tested by a human. (Not by a robot).

I watched some videos of Irving Crane (and a few other older players) and note that they stroke in this manner. If one experiments with their style of play accuracy improves. Apparently an improvement in accuracy depends upon one's ability to keep the cue stick on the intended line.

This improvement depends upon a reasonably stiff shaft and a well chalked tip that makes good contact with the cue ball at the right angle to make the shot. With the right equipment one can indeed test this hypothesis and determine how important a slow short back stroke and longer follow through improve accuracy over several types of shots. Crane and Hoppe obviously had it right, based on their personal experiments.

 

[crosseyedjoe]

If the shaft bends, this will change the angle of hit on the cue ball. These slight changes are important when translated into the consistent accuracies needed to make various shots.

That's probably it, the "natural English." Shaft bending is almost like applying a Back-hand English because the angle of contact changes. This could be unwieldy without proper practice, unintentional SQUERVO galore. Applying an accurate back-hand English using a stiff cue is hard enough, I wonder how troublesome that is for untrained Meucci user.

 

[Jal]

This is really puzzling. Ask anyone who knows how to use an old "whippy" Meucci and they will tell you that there is an observable effect of having slightly longer contact time......Technicalist says otherwise because the contact time is too short to make a difference...

I don't think anyone would seriously say that contact time is so short that a change in it can't make a difference. If it increased by 20% and the average force between the tip and ball remained the same, you would see a 20% increase in cueball speed and about a 20% increase in absolute spin. But as JoeW mentioned above, the average force doesn't stay the same. The physics of it is complicated enough that it's not easy to come up with a definitive answer. There's little question that a whippier shaft should increase contact time, but a number of other things change with it, some of which favor increased spin, and others that oppose it.

You have some technically knowledgeable people here but I doubt that any of them can say categorically that a whippier shaft doesn't produce, say, a larger spin/speed ratio - enough to be detected. Given the way the variables "adjust to each other", if there is any increase I doubt that it would be significant, but can't say for sure.

There might be a way of looking at the problem that cuts through the clutter and yields a clear and simple answer. I would like to hear it.

Jim

 

[Patrick Johnson]

A larger tip surface appropriately curved makes more contact with the cue ball.QUOTE]

Only a small fraction of any normal-sized tip (including my 10mm teenytinytip) makes contact with the cue ball at one time - check out the chalk mark on the cue ball to see; it's typically only about 1/8 inch in diameter. Why would adding more material at the edges of the tip (to make a larger tip) matter?

If the shaft bends, this will change the angle of hit on the cue ball.

I can see why you'd think this is true or matters (crosseyedjoe thinks so too), but if it was true the word would get around that whippy shafts are inaccurate and Meucci would be out of business.

Most importantly, if a shorter back stroke and a longer follow through are used the point of contact and energy transfer are more likely to be on the intended line. This last point is quite important and needs to be tested by a human. (Not by a robot).

OK (I guess), but this isn't a "special stroke"; it's a typical stroke delivered accurately. And why not by a robot? I think a robot might be essential to test this.

pj
chgo

 

[Patrick Johnson]

There's little question that a whippier shaft should increase contact time

I have a question: why?

pj
chgo

 

[Patrick Johnson]

You have some technically knowledgeable people here but I doubt that any of them can say categorically that a whippier shaft doesn't produce, say, a larger spin/speed ratio

I've tested it. None detected. Why would you speculate that it might?

pj
chgo

 

[Jal]

I have a question: why?

pj
chgo

A more flexible shaft acts like a weaker spring; it causes the hit to be softer. An object colliding with a weaker spring remains in contact longer.

There's another reason, I think, but it's very technical, having to do with the amount of additional distance the cue has to traverse compared to the cueball during impact, which affects the shape of the force/time curve, which in turn modifies the effective tip offset. This differential distance is a function of ball rotation during contact, tip radius, mechanical energy losses, and just how the cue bends. I may never know how this all pans out, but I've been looking at it. It could be that everything cancels everything else.

Jim

 

[crosseyedjoe]

I can see why you'd think this is true or matters (crosseyedjoe thinks so too), but if it was true the word would get around that whippy shafts are inaccurate and Meucci would be out of business.

pj
chgo

Isn't that the reason why Meucci is not so popular with new players?

If you think about what Danny Harriman said about "crooked/skewed" stroke, the slight bending totally makes sense. I asked the guy who created those billiards videos for Colorado State, although he doesn't have videos specifically about "whippy" cues, he believes the "whippiness" is an attempt to correct our natural "crooked stroke" thus minimizing squirt.

So my statement that "you need to know how to use a Meucci properly" is probably true.

 

[JoeW]

Shaft bending

Patrick Johnson said, "I can see why you'd think this is true or matters (crosseyedjoe thinks so too), but if it was true the word would get around that whippy shafts are inaccurate and Meucci would be out of business."

It makes sense. Something that bends when it hits will not place the same amount of force on all points of the circle that strikes the cue ball. In essence it is hitting with a glancing blow. There is more force at 3:00 o'clock than at 9:00 o'clock if the stick whips to the right.

A hammer driven straight will drive the nail straight. Hit at a glancing blow and the nail is bent. Hitting a cue ball with a glancing blow will drive it off line. I suspect that people learn to compensate for a stick that usually hits with a glancing blow and delivers a substantial amount of english

Of course we are discussing minute energy changes but if you look at the permissible error on some pool shots this can cause a miss on critical shots. It will also cause irregularity with regard to where in the pocket the object ball is placed, a lack of accuracy that may not be observed on easier shots.

Short stroke
Patrick Johnson said, "OK (I guess), but this isn't a "special stroke"; it's a typical stroke delivered accurately. And why not by a robot? I think a robot might be essential to test this."

Because the normal tremors in one's hand are one of the primary contributor to a lack of accuracy, a robot would not be of use. The inability to keep the stick on line is another major problem that a robot could not evaluate.

A robot that always has a straight swing does not evaluate the effect of follow through. I think that follow through is used to insure the player strikes the cue ball with equal force on all parts of the cue tip. It is not that follow through matters it is the equal force on the circumference of the tip that is important.

A longer back swing can (in most people) lead to taking the stick off line. A longer follow through is used to increase the likelihood that the tip will hit evenly (as intended).

To determine how well one is able to keep the stick on line one needs to compare their arm's ability to maintain a straight line with a long versus a short back swing. A robot cannot evaluate this.

About tip size, it makes sense that a larger tip allows more surface area to contact the cue ball and thus have more control. Calculating the area of the circle of hit for various size tips could be used to determine the percent increase in surface contact. More surface area leads to more control. A Lacrosse player has excellent control over the ball for long distances.

It seems to me that cue tips should have a concave surface to improve contact but I have yet to play with this idea.

Seems I have to edit every post to get the punctutation marks correct.

 

[Patrick Johnson]

A more flexible shaft acts like a weaker spring; ... An object colliding with a weaker spring remains in contact longer.

I'm guessing you mean that the weaker spring takes longer to uncompress and push the object away. Does this longer compress/uncompress action actually have time to operate fully during the time the tip is in contact with the ball, or does another action push the ball away before that has time to complete?

pj
chgo

 

[Jal]

I've tested it. None detected. Why would you speculate that it might?

pj
chgo

Given your interest in the science, I expect your tests were done with variables pretty well controlled (if you'd like to offer a more details...). But I can't dismiss what some of the other posters have been saying either. It's their testimony and the fact that the answer doesn't exactly pop out of a few simple equations (maybe it does if approached properly), that gives me reason to wonder.

Jim