Cue tip contact time

[Bob Jewett]

Is there a practical difference between "shot speed" and "acceleration into the ball"? Doesn't one just produce the other? And so "timing" is just getting the speed right? ...

Acceleration (by definition) is how quickly the speed (of the cue stick) is increasing. One way to hit the ball, and the way I usually hit the ball, is to accelerate before hitting the ball and to stop accelerating just before hitting the ball. That means the cue stick is coasting into the ball at peak speed. This method takes the least effort. I don't think about the timing -- I just hit the ball.

Another way is to still be increasing the speed of the cue stick when you hit the cue ball. This turns out to be equivalent to using a slightly heavier cue stick, maybe 1% heavier. I think most players do not hit the ball like this. If you want to try and extreme form, start with the cue stick an inch from the cue ball and then without any backstroke -- that's really hard to do if you have played a lot with a normal stroke -- come forward 8-10 inches, with a sort of normal stroke but hitting the cue ball much sooner in the sequence.

Some good players use the "still accelerating" method so it must have some advantage. It may help to keep a straighter stroke. Another is that if you limit your backswing, you need to accelerate through the ball to have the needed speed. I think Dr. Dave has some analysis on this but I couldn't find it.

 

[Jimmorrison]

It’s possible I don’t understand what this thread is about, but isn’t this concept already well documented in Golf? Moment of inertia.

 

[Bob Jewett]

It’s possible I don’t understand what this thread is about, but isn’t this concept already well documented in Golf? Moment of inertia.

The concept being discussed is the "great advantage" of increasing the contact time between the stick/club and the ball to increase spin on the ball. Is that a golf thing? How would a golfer go about doing that?

 

[Patrick Johnson]

Acceleration (by definition) is how quickly the speed (of the cue stick) is increasing. One way to hit the ball, and the way I usually hit the ball, is to accelerate before hitting the ball and to stop accelerating just before hitting the ball. That means the cue stick is coasting into the ball at peak speed. This method takes the least effort. I don't think about the timing -- I just hit the ball.

Another way is to still be increasing the speed of the cue stick when you hit the cue ball. This turns out to be equivalent to using a slightly heavier cue stick, maybe 1% heavier. I think most players do not hit the ball like this. If you want to try and extreme form, start with the cue stick an inch from the cue ball and then without any backstroke -- that's really hard to do if you have played a lot with a normal stroke -- come forward 8-10 inches, with a sort of normal stroke but hitting the cue ball much sooner in the sequence.

Some good players use the "still accelerating" method so it must have some advantage. It may help to keep a straighter stroke. Another is that if you limit your backswing, you need to accelerate through the ball to have the needed speed. I think Dr. Dave has some analysis on this but I couldn't find it.

I've discovered that placing my grip hand just an inch or so farther back than usual improves the reliability of my tip placement and speed, especially for more powerful shots. I guess that's the result of my stroke speed not "peaking" as early and/or not "dipping the tip" as much before contact - maybe that's what's meant by "timing"...?

pj
chgo

 

[dr_dave]

Is there a practical difference between "shot speed" and "acceleration into the ball"? Doesn't one just produce the other? And so "timing" is just getting the speed right?

You are right that acceleration creates speed, but the “timing” of the acceleration has a big effect on the final speed into the ball. If you accelerate late, or if you decelerate, your “timing” will not create the desired speed.

Regards,
Dave

 

[Patrick Johnson]

You are right that acceleration creates speed, but the “timing” of the acceleration has a big effect on the final speed into the ball. If you accelerate late, or if you decelerate, your “timing” will not created the desired speed.

Regards,
Dave

Yes, as per my comment just above to Bob.

Thanks,

pj
chgo

 

[BRussell]

... or that part of the tip had a slightly different hardness than other parts, or the shot speed was slightly different, or the acceleration into the ball (which is what probably best describes what most people mean by “timing”) was a little different. Many things can have small effects on the tiny amount of tip contact time, but I don’t think these slight changes are of any practical importance.

Regards,
Dave

It might be an interesting finding that people can tell when they’re getting a good hit, and this good hit is associated with a longer tip time - if that’s really what they find. The video can’t really prove that, we just need to take his word for it that there’s a correspondence between feeling a good hit and the longer tip time.

But he definitely hasn’t shown that it has anything to do with the timing of the stroke, which was his whole point. Maybe he’s somehow conflating stroke timing and tip-ball contact time.

We’ve all felt a good hit, like on a draw stroke and we really draw it back well, vs. when we’re trying to draw 4 ft. but it only comes back a foot. Is it possible that the tip contact time is longer on those “good strokes?” I would think so, if only because of what Bob said about tip contact time being longer on more off-center hits. So: A little lower hit, longer tip contact time, better draw, and feels like a better hit.

 

[pwd72s]

Timing-schiming. Why is it you know a miss is a miss the moment the cue ball leaves the tip? Why can't you know before the miss? If I did I'd sure as hell stand and line up again...

 

[Franky4Eyes]

Is this fundamental applicable to American pool? Is this something that may be specific to snooker due to contributing factors like weight of the balls, their diameter, and heavy ferrule material? No American players use a cue with a brass ferrule. The deflection of a snooker cue is almost alien compared to a standard American pool cue.
Just a curiosity if you'd follow this as an altruism that transcends all genres of billiards?

 

[Patrick Johnson]

So: A little lower hit, longer tip contact time, better draw, and feels like a better hit.

That's what I think too. We've all experienced getting "super draw" on occasion just because we hit closer to the extreme tip position than we're usually able to. Stroke "timing" might contribute to a tighter tip/ball contact pattern, which would allow us to work closer to the miscue limit in general and get better draw generally too.

The pic below illustrates this - a better player with a tighter "shot group" for tip/ball contacts (pic on the right) can aim closer to the miscue limit (red dot) and still only miscue an acceptable percentage of tries. We think we always aim near the miscue limit for maximum spin, but our brains know better and subconsciously force our stroke up a little to accommodate our personal shot grouping.

pj
chgo

View attachment 34895

 

[Bob Jewett]

Is this fundamental applicable to American pool? Is this something that may be specific to snooker due to contributing factors like weight of the balls, their diameter, and heavy ferrule material? No American players use a cue with a brass ferrule. The deflection of a snooker cue is almost alien compared to a standard American pool cue.
Just a curiosity if you'd follow this as an altruism that transcends all genres of billiards?

I'm not sure what you mean by "this fundamental".

In my experience, snooker cues squirt about the same as some pool cues.

The actual differences in materials (cues, shafts, tips, balls, cloth) are negligible for this discussion.

Some people get excited about the difference between a 12.7mm shaft and a 12.1mm shaft. Pretty much any shot can be made with shafts between 9mm and 14mm. Those may feel a lot different, but they can all move and spin the cue ball pretty close to the same. When you get down to 6mm and up to 16mm (both of which I've played with) you start to run into serious usability issues.

 

[Bob Jewett]

,,, Stroke "timing" might contribute to a tighter tip/ball contact pattern, which would allow us to work closer to the miscue limit in general and get better draw generally too....

Nice drawing. I think Mike Page has a video on Youtube about exactly this.

It would be interesting to measure the contact patterns of various players. I think it would be fairly easy with a pair of 1000 FPS cameras for left-right and up-down. A best draw shot would be a good test.

 

[BRussell]

Stroke "timing" might contribute to a tighter tip/ball contact pattern, which would allow us to work closer to the miscue limit in general and get better draw generally too.

View attachment 34895

I agree with the rest of what you wrote, but I don’t see the connection between stroke timing, which concerns speed, and cueing accuracy.

 

[Bob Jewett]

I agree with the rest of what you wrote, but I don’t see the connection between stroke timing, which concerns speed, and cueing accuracy.

I think that if you change your timing, such as stopping the stroke early, it can change where the tip hits the ball, so that repeatability of timing can affect cueing (tip placement) accuracy.

 

[Patrick Johnson]

Nice drawing. I think Mike Page has a video on Youtube about exactly this.

Yeah, I think I heard it from him *cough* years ago.

It would be interesting to measure the contact patterns of various players. I think it would be fairly easy with a pair of 1000 FPS cameras for left-right and up-down. A best draw shot would be a good test.

I'd like to see it.

pj
chgo

 

[pinkspider]

... Some good players use the "still accelerating" method so it must have some advantage. It may help to keep a straighter stroke. Another is that if you limit your backswing, you need to accelerate through the ball to have the needed speed. I think Dr. Dave has some analysis on this but I couldn't find it.

Would a stroke slip/throwing the cue fall in this category of 'still accelerating' as it strikes the ball? I find the biggest advantage is minimising the swing which helps to keep a straighter stroke

 

[pinkspider]

You are right that acceleration creates speed, but the “timing” of the acceleration has a big effect on the final speed into the ball. If you accelerate late, or if you decelerate, your “timing” will not create the desired speed.

Regards,
Dave

to me this is the best description of what good 'timing' is

 

[conetip]

Clearly when looking at the video evidence, I am seeing something that some of you are not. Snooker cues are typical at 9mm to 10mm tip diameter, and do have less endmass on the cue shaft. They are also mainly conical cues, so have a stiffer geometry over a regular pool cue. Traditional snooker cues are ash, with a fairly close grain many years ago. Now days , it seems they like the lower GPI Ash for the shafts.
They also like the Elkmaster or similar tips a lot as well. But the slow mo video at 35k F/S is the real stuff of interest to me. Lots to be learnt from that video alone.

 

[Bob Jewett]

Would a stroke slip/throwing the cue fall in this category of 'still accelerating' as it strikes the ball? I find the biggest advantage is minimising the swing which helps to keep a straighter stroke

If you actually throw the cue at the cue ball, it is not being accelerated when it hits the cue ball. It will actually be slowing down slightly due to rubbing on the bridge hand.

A slip stroke can have a shorter backswing which would make it more likely that acceleration is continuing through the ball.

The path of the cue ball is determined only by the speed, tip placement, direction and elevation of the cue stick at the instant of impact. Learning to play pool is learning how to do all of those correctly for each shot. A simple set of mechanics is all that is needed and I think it is easy to argue that a simple set is better than a complicated set.

 

[Patrick Johnson]

I think that if you change your timing, such as stopping the stroke early, it can change where the tip hits the ball, so that repeatability of timing can affect cueing (tip placement) accuracy.

Yes, that's what I was thinking. Also (maybe more stance/grip/bridge related), if your grip is "ahead of" or "behind" its optimum point when you hit the CB, it can cause your tip to be higher or lower than wanted at contact.

pj
chgo