If the tip and cue ball only touch so briefly, why the difference in power?

[Jal]

Hi Jim;

Perhaps, here's were we differ. Its my understanding, and I may well be wrong.

Spin increases several times per unit of force/energy while speed decreases purportionally with force/energy.

That factor enables us to spin the hell out of the CB and kill it as it hits a thin cut shot. What us old times use to call a soft stroke. Not hit hard, lots of cue speed and cue very low. Perhaps I don't explain well, but if you have seen Keith cut a ball backwards a few times and the CB moves about 6 inches after contact, it would become more understandable.

The result is actually,
with more energy-more offset-more spin-less speed
with same energy-more offset-more spin-less speed
the more the offset, the more spin and less speed

Of course, I may be wrong, but I haven't been drinking..........yet

Deadon, I don't mean to come off as Mr. Physics, because I'm not, but I think what we're discussing is very well understood. Ron Shepard and Dr. Dave Alciatore (Billiard Digest forum) derive equations for the relation between spin and speed as a function of tip offset in their various papers. And they completely agree with two of your statements (which are equivalent to each other as I see it):

"with same energy-more offset-more spin-less speed
the more the offset, the more spin and less speed"

The first statement though "with more energy-more offset-more spin-less speed", depends on how much more energy is put into it. For example, if you barely bump the cueball at centerball, then give it a healthy thwack at a large tip offset, it's obviously going to have more speed at the large offset. So if you up the stick's speed as you increase offset, you can keep the speed of the cueball constant, or even make it go faster. But the spin rate will go up even faster than speed. Make sense?

Jim

 

[Doug]

Vernon's shot

Tell Vernon, if he tells me the WHOLE SECRET to this shot that I will take the secret to this shot to my grave. Actually, I am serious. I have moved the object ball toward my hole about 6 inches only once in hundreds of tries. FTR, I believe that I can make ANY shot that anyone else in the world can make. I just have to learn or teach myself how to make it. This is one of the few shots in the world that I have been stupid enough to believe that it an be made without ever having seen it being made.

I have never seen this shot made and have only heard the folklore of this shot and others in which Vernon has been the central figure.

Best Regards to Vernon.
JoeyA

BTW, Doug do you know how to use www.cuetable.com ?
It would be GREAT and I know WEI the creator of cuetable would help if you were interested in building a catalog of Vernon's shots for posterity. That previous shot was depicted using www.cuetable.com and it is free, fun and after you get used to it, easy to use. It could be called the Vernon Elliott Collection and would be famous for generations to come.

Good idea Joey and I will talk with Vernon about that possibility. You should have been at the Bank Pool Hall of Fame this past year at DCC when Vernon was inducted because Buddy Hall, who was on the road with Vernon for several years, and Efren Reyes were seated with Vernon. Buddy was telling Efren of some of Vernon's shots and the one you referred to Efren said was impossible to make. Buddy's response was "well he would have taken your money along with all the others".

 

[Patrick Johnson]

That wasn't my question. Proportionately means "in the same ratio", not "by the same amount".

pj
chgo

 

[Jal]

....I have never seen this shot made and have only heard the folklore of this shot and others in which Vernon has been the central figure.

Hi Joey,

Since I argued with you that this shot is a near impossibility in the past, I feel obliged to point this video out:

http://www.youtube.com/watch?v=uHf3o6FtNnQ

That's Bob Jewett doing the shooting, I believe. The image quality and camera perspective help to keep the secret safe, but it's obvious that a tremendous amount of shot speed is not necessary. I'm pretty sure, but not positive, that a bouncing cueball is the key ingredient.

Jim

P.S. It should also be pointed out that your term "squerve" (a variation of Patrick Johnson's "squirve") made it into Dr. Alciatore's glossary here (you were both given due credit when the word was suggested to him):

http://www.engr.colostate.edu/~dga/pool/resources/glossary.pdf

 

[JoeyA]

The Nobel Peace Prize

Hi Joey,

Since I argued with you that this shot is a near impossibility in the past, I feel obliged to point this video out:

http://www.youtube.com/watch?v=uHf3o6FtNnQ

That's Bob Jewett doing the shooting, I believe. The image quality and camera perspective help to keep the secret safe, but it's obvious that a tremendous amount of shot speed is not necessary. I'm pretty sure, but not positive, that a bouncing cueball is the key ingredient.

Jim

P.S. It should also be pointed out that your term "squerve" (a variation of Patrick Johnson's "squirve") made it into Dr. Alciatore's glossary here (you were both given due credit when the word was suggested to him):

http://www.engr.colostate.edu/~dga/pool/resources/glossary.pdf

Jim, thanks for the update on the youtube. If that was Bob Jewett shooting that shot, he must have put some type of silicone or other "lubricant" on the object ball and maybe even the cue ball. He doesn't have the speed to accomplish that shot without some "help" and it's possible he could have doctored the table.

Thanks for the update on Dr. Dave Alciatore's glossary. I can't believe Patrick squerved in there right along side of me. It must have been Mike Page who volunteered Pat's name.

It is apparent that I will have to start a campaign to keep him from sharing the glory of being admitted to Merriam-Webster. That is afterall the next stepping stone and after that, well you know... the big money stuff- The Nobel Peace Prize. I would have a tough time sharing all that dough with Pat.
JoeyA

 

[sygfrid]

Actually it is FORCE = MASS X ACCELERATION from Newton's second law. And just so you know... MOMENTUM = MASS X VELOCITY.

I stand corrected

 

[Bob Jewett]

... If that was Bob Jewett shooting that shot, he must have put some type of silicone or other "lubricant" on the object ball and maybe even the cue ball. ...

Lubricant would be the wrong thing, and the cue ball was not doctored.

 

[arsenius]

Lubricant would be the wrong thing, and the cue ball was not doctored.

So...you don't deny doctoring the table...

Just kidding! Great shot!

 

[patrickcues]

Stroke= length of contact between the cue tip and the cue ball. The longer the contact to the cueball the more juice you will put on it. Provided that you not babying the shot or hammering the shot A good med stroke for me is the best way to get the cueball to do as I want it to do. Now I am only talking about myself here. Everyone has there own stroke.

 

[Cornerman]

Stroke= length of contact between the cue tip and the cue ball. The longer the contact to the cueball the more juice you will put on it. Provided that you not babying the shot or hammering the shot A good med stroke for me is the best way to get the cueball to do as I want it to do. Now I am only talking about myself here. Everyone has there own stroke.

Well, I'm glad that's settled. I'd hate to think there were 4-5 pages discussing contact time and why it doesn't do what people think it does.

Fred

 

[Andrew Manning]

Well, I'm glad that's settled. I'd hate to think there were 4-5 pages discussing contact time and why it doesn't do what people think it does.

Fred

I love the "definitive answers" you get in a lot of threads. They really help clarify things.

-Andrew

 

[JoeyA]

Lubricant would be the wrong thing, and the cue ball was not doctored.

ALL RIGHT! So it was you. At least I got you to respond on this shot.

Now, would it do any good to scan your whole web site to find out what is the right thing to apply to the object ball, or perhaps you might offer a mustard seed size suggestion as to how I might duplicate your phenomenal effort?

I do think, like Jim that a little bounce to the cue ball helps. At least that's the way I got it to go about 6 inches one day on a cold day in ...well, we really don't have cold days but it was a pretty cool day with low humidity.
Thanks,
JoeyA

OH yeah, PM's are just fine with me in case that is your preference. Just put your mailing address for where the check needs to be mailed.

 

[crosseyedjoe]

In my opinion this is the answer.

I think the great power stroke is applied by the rate of change of the acceleration during the moment of the hit.

. . .

Duh, that can't be. It has to be more complicated than that. LOL,


----

however, I think you meant "rate of change of the velocity."

 

[Bob Jewett]

ALL RIGHT! So it was you. At least I got you to respond on this shot.

I've commented several times in threads about the impossible cut (attributed to Efren) and the impossible bank (attributed to Vernon Elliott).

Now, would it do any good to scan your whole web site to find out what is the right thing to apply to the object ball, or perhaps you might offer a mustard seed size suggestion as to how I might duplicate your phenomenal effort?

Make sure the object ball is as sticky as possible. In some rooms, this is not a problem. Also, you could subscribe to Billiards Digest, where I discussed the shot.

I do think, like Jim that a little bounce to the cue ball helps.

To the best of my knowledge, it does not. On the impossible bank, I try to keep the stick as level as possible. The cut shot needs a little more elevated cue due to the nearness of the pocket, but I'd rather have the stick more level than less.

On the cut shot, a friend of mine had tried it for an hour or two to the extent that his arm was sore. I set it up and made it on the second try. My next success, which was for the video, took an hour or so.

 

[JoeyA]

Biliards Digest

I've commented several times in threads about the impossible cut (attributed to Efren) and the impossible bank (attributed to Vernon Elliott).


Make sure the object ball is as sticky as possible. In some rooms, this is not a problem. Also, you could subscribe to Billiards Digest, where I discussed the shot.

To the best of my knowledge, it does not. On the impossible bank, I try to keep the stick as level as possible. The cut shot needs a little more elevated cue due to the nearness of the pocket, but I'd rather have the stick more level than less.

On the cut shot, a friend of mine had tried it for an hour or two to the extent that his arm was sore. I set it up and made it on the second try. My next success, which was for the video, took an hour or so.

OK, that's real nice.

Billiards Digest is a quality magazine. I used to subscribe to a four different pool publications but got burned out reading them every month and have quit cold turkey. I have been thinking about trying BD again.

Thanks,

JoeyA

 

[JoeyA]

Pool School

Lubricant would be the wrong thing, and the cue ball was not doctored.

Randy, it almost looked like you were getting ready to tell me what the right thing was. OK so lubricant would be the wrong thing...................

Do I have to come to your school to learn this critical secret? OK, you can PM me but be warned, I often act just like a radio tower.

Is your pool school still located at www.sfbilliards.com ?


JoeyA

 

[Bob Jewett]

... it almost looked like you were getting ready to tell me what the right thing was. OK so lubricant would be the wrong thing...................

Do I have to come to your school to learn this critical secret? OK, you can PM me but be warned, I often act just like a radio tower. ...

You have the directions, Grasshopper. Follow the only path that remains. The answer does not lie with the guru.

 

[elvicash]

Duh, that can't be. It has to be more complicated than that. LOL,

----

however, I think you meant "rate of change of the velocity."

Dude I mean exactly that......

First of all what is a "jerk"?

It is the third derivative of position, the second derivative of velocity, or the first derivative of acceleration.

For your information Acceleration is the rate of change of velocity which is what you mentioned in your reply.

Thus a jerk is the rate of change of acceleration.

I propose that the players with the greatest strokes snap it at exactly the right time and increase the rate of acceleration at the moment of impact which makes the rate of change of velocity (cue at grip thus tip speed) to be much more vertical at that time and this applys more energy directly into the recieving object whether it is a cue ball or a golf ball or a baseball. I have seen many of the greatest play and without doubt some have an ability to put more action on the ball.

In my opinion it is definitly more than tip velocity and quality of bridge.

I do not have 12,000 fps camera so I cannot refute Bob Jewett using that technique. However I do have some ideas on how to test this and will have to followup in a later thread.

 

[Jal]

Dude I mean exactly that......

First of all what is a "jerk"?

It is the third derivative of position, the second derivative of velocity, or the first derivative of acceleration.

For your information Acceleration is the rate of change of velocity which is what you mentioned in your reply.

Thus a jerk is the rate of change of acceleration.

I propose that the players with the greatest strokes snap it at exactly the right time and increase the rate of acceleration at the moment of impact which makes the rate of change of velocity (cue at grip thus tip speed) to be much more vertical at that time and this applys more energy directly into the recieving object whether it is a cue ball or a golf ball or a baseball. I have seen many of the greatest play and without doubt some have an ability to put more action on the ball.

In my opinion it is definitly more than tip velocity and quality of bridge.

I do not have 12,000 fps camera so I cannot refute Bob Jewett using that technique. However I do have some ideas on how to test this and will have to followup in a later thread.

People have proposed that changing the acceleration (force on the cue) at impact does something significant. It doesn't.

You're proposing something more subtle: that changing the rate of change of acceleration does something significant. If you know about derivatives and integrals and all that, what would make you think this? You're not only not getting much change in cue velocity, you're not even getting much change in acceleration (force). It takes time for acceleration to boost velocity, and jerk to boost acceleration. The short impact period is just not enough.

Those who get more action are simply able to hit closer to the miscue limit more consistently (without miscuing), and/or are able to provide increased peak levels of acceleration before impact, and/or are able to sustain higher levels of acceleration after passing through the peak, and/or shift their acceleration profile so that all points on the force-time curve occur later during the stroke.

Sure, if somone could exert 100 lbs of force at impact, that would be significant. But high-speed (break) shots only involve peak forces in the range of something like 10-20 lbs, so it's highly unlikely that anyone could approach this.

Jim

 

[elvicash]

I think the people who get the most action actually stay in touch with the cue ball for longer periods of time.

What I would like to see if someone has the fast camera is some shots where the cue ball is stroked by some world class players and some B players.

Have them shoot the same type of shots say a 4ft cue ball to object ball shot draw the cue ball back to end rail. I propose the better more consistent stroke will show to be in touch with the cue ball a longer period of time.

I suggest the best players stroke has a different look at impact when graphed over tip location vs time relative to the object ball.I also think some sticks play better than others.

I cannot prove it but that is what I think. I think they snap there wrist or whatever and put more power into the ball for a given shot.