For the particular goal I cited, I think it's clear that you want maximum stick speed. That is, to get maximum RPMs on the cue ball. My response was not about speed accuracy.Jal said:
Shaft type and amount of draw.
- Thread starter Wolven
- Start date
Jim...When the contact time is 1 or 2/1000's of a second, the arguements you put up to justify increases in dwell time between tip and CB are moot. The difference is so infinitesimally small, it can't even be measured (let alone noticed by the naked eye), without the aid of high speed photography, like what was done in the Jacksonville experiments. At 4000 f.p.s. (and Bob Jewett mentioned that some of the photography was done at an incredible 12,000 f.p.s.) you can slow down the film enough to visually see, and mechanically measure small differences. IIRC, they used different shafts and different tips for these experiments, and overall there were not substancial differences, with the possible exception of CB squirt & cue stick deflection (which, imo don't significantly contribute to a smooth draw stroke). Do I have this correct Mr. Jewett?
Scott Lee
www.poolknowledge.com
Scott Lee
www.poolknowledge.com
Well, the cues tested looked to work nearly the same as close as we could figure from the video except one experimental composite shaft that seemed to miscue a lot, but it was not quite an ordinary miscue. It seemed to not slow down as much when hitting the cue ball so that it would kind of drag on the side of the ball towards the end of any spin shot. It felt really lousy to play with, especially for draw shots.Scott Lee said:
As grist for the mill of this discussion, the highest quality draw I see at the pool hall I play in is by a snooker player who plays pool with a light ash single-piece cue stick with a 10mm brass ferrule. That is, I constantly remark to myself, "how did the ball draw so for a hit that soft." On a 6x12 snooker table, he is also able to play from the jaws of a corner pocket and draw the cue ball straight back off blue into that corner. If you give him ten tries, he'll bet on it. Of course he does this with an open bridge.
But that's what has me flummoxed. If you look at the integral of a pure sine wave over time, the most cue speed is obtained when impact occurs at a phase angle of 113 degrees ("accelerating through" so to speak), rather than at 180 degrees (coasting through). In fact, I think it works out to about 95-98% of the speed you would get if you applied the peak force throughout (but I'll have to look at this more). This is for a fixed distance (fixed bridge length).Bob Jewett said:
Granted, we don't execute a pure sine wave, but you do get an increase in cue speed for a variety of "impure" wave forms. I'm probably not the mathematician to prove for which class of wave forms this holds true, and which ones it doesn't, but I think it's likely to be true for the "sine-like" strokes we probably generate (judging from some of the accelerometer data).
Jim
i've noticed i can do some things with LD shafts that i couldn't do with a traditional shaft. but now that i've stuck with traditional shafts for about a year i can do more with a traditional shaft than i used to be able to do with a LD shaft.
i gotta think that you can do more with less stroke with a LD shaft than with a traditional shaft but there's nothing you can do with a LD shaft that you couldn't do with a traditional shaft once your stroke becomes more developed.
i gotta think that you can do more with less stroke with a LD shaft than with a traditional shaft but there's nothing you can do with a LD shaft that you couldn't do with a traditional shaft once your stroke becomes more developed.
BRKNRUN said:
This is exactly why a robot test can answer the question. With a human being, the variables would make any conclusions inconsistant. You may be stroking differently on every test shot. If the robot is consistant, and the results using different shafts are virtually the same, then is becomes fairly obvious that the shaft doesn't have much effect on draw. It's all in the stroke.
Steve
True story- App. 25 yrs. ago, at Tuckers poolroom in Chas. S.C., Elldridge's son bet him he could put an object ball on the spot, shoot from the kitchen, pocket ithe ob, and draw the cb to the side rail to where it hit the rail on the kitchen side of the 2nd diamond. While using an unaltered, except for chalk BROOMSTICK! Elldridge bet him $500 he couldn't do it- he lost!
I don't even know how that is possible. And it takes a world class stroke to do it with a cue stick. But he did it!
Now, if any of you really think that the type of cue or tip make a lot of difference........well.............
I don't even know how that is possible. And it takes a world class stroke to do it with a cue stick. But he did it!
Now, if any of you really think that the type of cue or tip make a lot of difference........well.............
Holy cow Neil! I don't think I've EVER seen anyone do that. You say the CB drew back TWO DIAMONDS above the side pocket, before it hit the rail? That has to be some kind of stroke...and I cannot even imagine it with a broomstick, let alone a finely tuned pool cue! Sure would love to have been the fly on the wall that day! I'm guessing it had to be some kind of masse' stroke, with the broomstick.
Scott Lee
www.poolknowledge.com
Scott Lee
www.poolknowledge.com
Neil said:
Jal said:
This is off the subject of this thread, but ....
I think we have two different ways of viewing this sensitivity thing.
Both are of the form
Assuming fixed AAAA, ball speed is least sensitive to BBBB when condition CCCC is met.
For Jewett,
AAAA = maximum stick speed
BBBB = errors in forearm angle at impact
CCCC = the intended forearm angle at impact has zero force
For Jal,
AAAA = maximum force during the stroke
BBBB = errors in stroke timing
CCCC = the force at impact is at a particular spot past maximum at impact
Both seem to me to be true statements as far as they go. Their value though depends on
--- whether AAAA, the thing that's assumed fixed, is really something we're trained to readily fix at a certain value.
--- whether BBBB/CCCC refer to a variable we readily control.
I think Jal's interesting approach suffers under this kind of analysis.
I think it's the time integral of the force and not the maximum value of the force that we're trained to summon at a certain value. What we know how to do is get the stick going at a certain maximum speed, and we intuitively use more force when we use a shorter backstroke and less force when we use a longer backstroke. I don't think summoning a certain maximum force is what we're good at.
I don't think Jal's "timing" variable, essentially the period/frequency of the force sine function is a reasonable variable that is under our control. I think the timing is too tied to the stroke geometry.
Scott Lee said:Jason...No I am not confused. Dwell time between the tip and CB is about 1/1000th of a second (double that for a soft tip). BTW, it takes you 4/1000ths of a second to blink your eye! Nothing you can do increases that time frame, so the CB is gone "instantly" off the tip. As a result, no tip, shaft, or anything else can significantly change or affect the outcome of the "action" put on the CB. As for getting more or less draw with a Predator shaft, as opposed to a conventional shaft...that is baloney! I will draw the CB the SAME distance (under the same cloth and ball conditions) with ANY cue/shaft...as long as it has a decent tip on it. So...if you're sure of what you're talking about, we can post a significant wager, and meet somewhere, to conduct the experiment. The quality of your stroke has EVERYTHING to do with how much, and how consistently you can draw the CB...and follow it, and stun it, and english it...etc.
Am I an instructor?
LMAO I've only been a professional instructor for the past 30 yrs. Hard to believe that you've posted here as long as you have, and you don't know that I'm an instructor...or that you haven't once clicked on the link to my site.
Scott Lee
www.poolknowledge.com
How about "you are suppose to be an instructor?"... Is that better. You didn't get the first one. I don't care how long the tip stays on the CB, it has an effect on it. That is what puts the spin on the ball and your statement that it doesn't is completely wrong. Take the chalk of the tip and try spin. If that little bit of time isn't enough for a tip to have an effect, no chalk shouldn't make a difference. That softer tip will have the same effect as putting chalk on the cue, it will grip the ball better. Put a rubber tip on and see the spin you can get. For a top instructor you dismiss a lot of things that are basic. Equipment, balls, and the tables all have an effect.
I will wager everything I have on the tip making a difference. I will pick a few tips and we can give it a try!
Patrick Johnson said:
Maybe so, but I haven't analyzed any of the evidence myself. I'm sure a lot of very smart people have looked into it. All I see here is a bunch of contradiction.
Maybe I'm wrong and acceleration has nothing to do with it. At the same time, I've seen a lot of really good players hit shots with incredible spin/speed ratios that don't seem to be explained by cue velocity alone.
Jason...I've spent the better part of 40 yrs learning what I know...and I'm still learning new things almost every day! Now it appears that you're misreading or misquoting me. I never said the tip contacting the CB had no effect. I said you can draw the CB with ANY decent tip (or any shaft, which is what this thread is about), and there's no difference between brand names. There's a big difference there. The chalk is what allows the tip to stay on the CB, when striking offcenter. It provides friction. Without chalk you'd miscue every time you tried to stroke the CB anywhere but dead center. The same thing will happen with a soft tip, with no chalk. I've played with the rubber tips, and you don't need chalk for them, as the rubber provides friction between the cue and CB. The main problem with them was that they wouldn't stay on the cue...and one reason why nobody uses them anymore.
The things I dismiss are the myths of pool...of which there are plenty out there. That's my job...to teach the truth, and help my students sort out, and understand what is real and what's not. If you read my post, I mentioned that dirty balls and dirty cloth can have a negative affect on achieving maximum draw. Cue sticks and cue tips do not...as long as they are of reasonable quality. You could learn a lot by coming to pool school. Now...if you still want to wager that one tip draws better than another, you got a stiff bet mister!
Scott Lee
www.poolknowledge.com
The things I dismiss are the myths of pool...of which there are plenty out there. That's my job...to teach the truth, and help my students sort out, and understand what is real and what's not. If you read my post, I mentioned that dirty balls and dirty cloth can have a negative affect on achieving maximum draw. Cue sticks and cue tips do not...as long as they are of reasonable quality. You could learn a lot by coming to pool school. Now...if you still want to wager that one tip draws better than another, you got a stiff bet mister!
Scott Lee
www.poolknowledge.com
Jason Robichaud said:
Neil...Like this?
Are you talking about CB position A or B...I thought you meant B, which would take a miracle stroke. A is not too tough, imo.
Scott Lee
www.poolknowledge.com
Are you talking about CB position A or B...I thought you meant B, which would take a miracle stroke. A is not too tough, imo.
Scott Lee
www.poolknowledge.com
Neil said:
This depends on what assumptions you make about the maximum. I assume that a player with experience can set his bridge and body position to achieve maximum velocity at impact. If he does that, he will achieve more stick speed at impact than someone who sets up for 113 degrees and uses the same power in the shot. Further, I'll claim on limited info that good players do set up for impact at maximum velocity.Jal said:
I look at it this way: if you take your player who intends to hit at 113 degrees and you slyly move the cue ball forward while he's not watching so he actually hits at 180 degrees, he will hit the ball harder. He will see this large improvement in ball speed, and within a few shots he will be setting up a little farther back from the ball and hitting it harder with the same stroke.