curving an object ball....

[dr_dave]

My quick summary: When a banking wizard of John's caliber, with tens of thousands of hours on the table (in the lab) says a banked ball can bend, I start out believing him in my hypothesis. The questions become why, and how much.

I also had faith it was possible to bend a bank (for the reasons summarized on the bank shot bend resource page), but I've always been skeptical if could be bent the amount some people have suggested with anecdotal claims. Also, sometimes when people think a bank is bending (e.g., as Freddy "The Beard" did when he presented the "bank bender" shots on his DVD), it actually isn't. The new challenge that Bob and I will post soon (which is actually easier than Bob's original challenge) will provide a fairly easy way to determine how much a bank can be bent. I honestly and sincerely look forward to seeing the best that is possible.

For those interested, I've made many changes and improvements to the bank shot bend resource page (mostly in an attempt to make it more palatable to some of the Naysayers). Again, I think the new challenge will help determine the "how much?" question. And I think the excerpt below explains the physics of the "how?" question. And I think the video posted showing the best bank bend will clearly show the best combination of speed, spin, angle, ball hop, etc. This will help complete the answer to the "how?" question.

from the current version of the bank shot bend resource page:

It is possible to bend a bank since the cushion nose can impart masse spin (about an axis perpendicular to the rail) and topspin (about an axis parallel to the rail), both of which can curve the OB's post-rebound path; but bending a bank a significant amount is not as easy as some people think. One reason a large bend cannot occur is that much of the small amount of topspin or masse spin imparted to the ball during cushion nose compression has an effect or "takes" (and dissipates) only when the OB first interacts with the bed of the table when the cushion nose pushes the ball down into table. This effect can help "twist" or "shorten" the bank, but only the curving spin that remains after the bounce out of the "rail groove" can contribute to bending or curving the OB's path to the pocket. The downward push into the table (into the rail groove) is what causes the OB to bounce into the air with fast-speed banks. While the OB is in the air, it can head only in a straight line (relative to the table). But when it lands, any remaining curving spin can start to "take" and bend the post-rebound path. On slicker cloth, less spin will be lost during the first bounce out of the rail groove, and any remaining curving spin will take longer to bend the ball's path, making the curve more clearly visible. Once the curving spin totally dissipates, the OB heads in a straight line to the pocket.

It would be interesting to modify the challenge to "who can bend the ball the most"?

Again, that is exactly what we are doing with the modified challenge.

Thank you for your input,
Dave

 

[BRussell]

Dr. Dave - in previous posts you've made reference to curving a banked ball "a practical amount." Since I think we've moved from whether it's possible at all to how much is possible, is there some cutoff you think is practical/real - 1/4", 1", etc.?

I would think that if there was some cost to curving the ball, like using extreme english or hitting it harder than would otherwise be advisable, curving only a small amount - say, 1/4" - might not be practical. On the other hand, if it's just a natural consequence of banking how you'd otherwise want to hit it, then even a small amount of curve might be preferable.

In addition, it would be helpful to understand the benefits. Getting around a blocking ball is obvious, but JB also says it can help by coming into the pocket straighter rather than an angle. At least that's what I think he has said about "making the pocket bigger." But I would think that would only be desirable in the side pocket.

 

[dr_dave]

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I want to thank the moderators for finally doing the right thing. This "English!" guy has been running amok, causing disruptions, creating vitriol (which contributed to the banning of others), and in general making AZB a less friendly and less pleasant place to participate, for far too long, IMO.

It was a Happy Easter, indeed.

Regards,
Dave

 

[crabbcatjohn]

I'm thinking

I'm thinking you are going to be a little surprised how much a ball can actually bend once this challenge is done. The part that I've been surprised most by is how close minded and quick to judgement some people have been.

 

[Bob Jewett]

... The part that I've been surprised most by is how close minded and quick to judgement some people have been.

If you mean "justifiably skeptical", then I'm guilty as charged.

 

[HawaiianEye]

Many moons ago, here in St. Louis, the usual suspects were hanging out at an old time pool hall here. The joint had one of those old-style 10' Brunswick billiard tables with the three inch slates and huge elephant thick legs on it and ivory diamonds in the rails. These tables are generally known around the country as "Big Berthas."

Anywhos, Harry Sims, one time US National 3-Cushion Champion, was telling all the rail birds how tough it was to hit an 11-railer and how he was one of the "few players" that could do it. IOWs, that you needed to have a pro player stroke to execute the shot...

Well, being the great, unwashed, young nonbelievers we all were we started messing around with the shot.

"Banking Billy" started trying to set up the shot on the old Arcade and, long story short, in about 20 minutes he found "the spot" for the CB and made the 11-railer on the old Brunswick. Then a bunch of us started shooting it. About six or seven of us all made it. By the end of the night we could have pulled McGoorty's "drunken Girl Scout" off the street and had her make it.

Ever since then I've been a little dubious about special, magic, only pros got it strokes.

Lou Figueroa

How about you set it up next time you are at the pool hall and video it and show us.

 

[Bob Jewett]

How about you set it up next time you are at the pool hall and video it and show us.

11 cushions on a carom table is not hard on new cloth. Even I've done it. Eventually. Mike Massey did it on his third attempt, never having seen the shot before, so it does seem to help to have an above-average stroke.

 

[pool101]

Thanks for taking the time to try the shot and do the video.

The ball very clearly curves.

Your check is in the mail. :wink:

Can you estimate how much the bend actually was? That is, if you put a ball on the banking rail where the object ball left (a little to the left of the first blocking ball) and a ball by the pocket where the ball went in (which I think can be judged pretty accurately), and put your straight edge between them, how much overlap is there for the middle blocking ball? Here is a diagram:

View attachment 417154

I'm just asking for a best estimate. I hope the marks are still on the table.

As for the $500 for teaching me how, I suppose the point is moot now since I saw from your video exactly how it is done. Thanks. :grin: I at least owe you a steak dinner. Maybe I should buy John one also. I'll put the $500 into the One-Inch Bent Bank Prize.

As Dave mentioned, there is a consolation prize for best effort and so far you are in first place even lacking the (fussy, bureaucratic, science-guy) documentation.

Here is a video with the measurements.
https://www.youtube.com/watch?v=Q78s5Hq88sA

 

[cajunfats]

The Banana Bank

Back in the 80's while playing against a guy named Wayne "The Kansas Wheat Farmer" Findlay, I executed such a curved shot on a 4 1/2 x 9 ft. Brunswick Sport King with 80/20 Wool Cloth. A long discussion ensued as to how such a shot is possible. Without scientific analysis,I showed him...about 10 more times. Bank and One Pocket Players have known about this effect for decades,and is one of the closest guarded secrets.Well,...was. lol. It is such a beautiful effect to observe. I imparted this shot 20 plus years ago to a young protege' of mine, Chris Trulin,AZB name Run the Century, who was accomplished at other games and was beginning to delve into One Pocket and Bank Pool. He even called me when he executed it on his 9 Ft. Diamond. Quite the feat on Simonis Cloth,I must say. This thread is intriguing and I have read some interesting comments. Just wanted to offer my own observations,that's all. Thanks.

 

[Rubik's Cube]

If you mean "justifiably skeptical", then I'm guilty as charged.

Good afternoon, Mr Jewett.

I thought the gentleman was referring to the folks who have been directing a constant stream of invective towards you and Dr. Dave. When they write about lack of respect it displays a level of chutzpah seldom seen since Lizzie Borden threw herself upon the mercy of the court as an orphan.

Anyway, a question for you, sir.

Unless I'm mistaken, in a recent post Dr. Dave stated: "whilst in the air an object ball can only move in a straight line." Is this correct? Could a heavily spinning ball not turn even slightly when airborne?

Many thanks for all your hard work and contribution to the forum, it is much appreciated.

 

[HawaiianEye]

Good afternoon, Mr Jewett.

I thought the gentleman was referring to the folks who have been directing a constant stream of invective towards you and Dr. Dave. When they write about lack of respect it displays a level of chutzpah seldom seen since Lizzie Borden threw herself upon the mercy of the court as an orphan.

Anyway, a question for you, sir.

Unless I'm mistaken, in a recent post Dr. Dave stated: "whilst in the air an object ball can only move in a straight line." Is this correct? Could a heavily spinning ball not turn even slightly when airborne?

Many thanks for all your hard work and contribution to the forum, it is much appreciated.

I'm not a scientist, but I don't think you'll ever get a ball turning just by the air "friction" alone, if that is what you mean. The ball has to be spinning before it becomes airborne, as it comes off the rail, or from a masse-type shot, for it to then turn when it hits the table.

Maybe if you get Cannonball Jones or somebody to hit it 150 MPH in hurricane winds it may have some effect. I don't think you are going to see it in a normal pool game.

 

[Bob Jewett]

I'm not a scientist, but I don't think you'll ever get a ball turning just by the air "friction" alone, if that is what you mean. The ball has to be spinning before it becomes airborne, as it comes off the rail, or from a masse-type shot, for it to then turn when it hits the table.

Maybe if you get Cannonball Jones or somebody to hit it 150 MPH in hurricane winds it may have some effect. I don't think you are going to see it in a normal pool game.

Yes, there is not enough friction or speed for a pool ball to curve to a visible extent in the air. Also, unlike a baseball, a pool ball doesn't have seams to help with aerodynamics.

 

[Rubik's Cube]

I'm not a scientist, but I don't think you'll ever get a ball turning just by the air "friction" alone, if that is what you mean. The ball has to be spinning before it becomes airborne, as it comes off the rail, or from a masse-type shot, for it to then turn when it hits the table.

Maybe if you get Cannonball Jones or somebody to hit it 150 MPH in hurricane winds it may have some effect. I don't think you are going to see it in a normal pool game.

Many thanks, sir.

I agree that there could never be any significant movement off a straight line whilst airborne, but thought a very slight curve might be possible if the ball is spinning.

Kind regards,
RC

 

[dr_dave]

Dr. Dave - in previous posts you've made reference to curving a banked ball "a practical amount." Since I think we've moved from whether it's possible at all to how much is possible, is there some cutoff you think is practical/real - 1/4", 1", etc.?

I would think that if there was some cost to curving the ball, like using extreme english or hitting it harder than would otherwise be advisable, curving only a small amount - say, 1/4" - might not be practical. On the other hand, if it's just a natural consequence of banking how you'd otherwise want to hit it, then even a small amount of curve might be preferable.

These are difficult questions to answer, and I think the answers will depend on the person, the situation, the equipment, and conditions.

I think that anybody who participates in the bank bend challenge will be able to answer the questions on their own. For example, if it takes 50-100 attempts to get a small amount of bend around an obstacle ball that is blocking only a small portion of the straight-line path, then the technique is probably not that useful in practical game situations (where you only get 1 attempt), especially if the risk of hitting the obstacle ball is large (e.g., if it will break up your opponent's problem balls in 8-ball).

In addition, it would be helpful to understand the benefits. Getting around a blocking ball is obvious, but JB also says it can help by coming into the pocket straighter rather than an angle. At least that's what I think he has said about "making the pocket bigger." But I would think that would only be desirable in the side pocket.

Again, I think people who participate in the challenge will answer this on their own. However, if the amount of curve possible is small, any potential "making the pocket bigger" effect will also be small and might be offset by any "making the pocket smaller" effects associated with executing the bend technique and using fast speed. For those interested, I have more info on this topic on the advantages of fast-speed banks resource page.

Regards,
Dave

 

[dr_dave]

I'm thinking you are going to be a little surprised how much a ball can actually bend once this challenge is done.

I hope so. That's the point of the challenge ... let's find out what's the best possible for an ideal shot under ideal conditions after a large number of attempts by a large number of people.

Regards,
Dave

 

[HawaiianEye]

These are difficult questions to answer, and I think the answers will depend on the person, the situation, the equipment, and conditions.

I think that anybody who participates in the bank bend challenge will be able to answer the questions on their own. For example, if it takes 50-100 attempts to get a small amount of bend around an obstacle ball that is blocking only a small portion of the straight-line path, then the technique is probably not that useful in practical game situations (where you only get 1 attempt), especially if the risk of hitting the obstacle ball is large (e.g., if it will break up your opponent's problem balls in 8-ball).

Again, I think people who participate in the challenge will answer this on their own. However, if the amount of curve possible is small, any potential "making the pocket bigger" effect will also be small and might be offset by any "making the pocket smaller" effects associated with executing the bend technique and using fast speed. For those interested, I have more info on this topic on the advantages of fast-speed banks resource page.

Regards,
Dave

A high-caliber player who knows how to do this will know when it is practical to attempt it. The same way they know when to try to jump a ball or a masse shot. The average player maybe should not even attempt it, if they don't have the confidence in themselves.

I'm sure John Brumback knows exactly when to try it.

 

[dr_dave]

Here is a video with the measurements.
https://www.youtube.com/watch?v=Q78s5Hq88sA

Thank you for doing this. Our new procedure will make all of this much easier.

BTW, are you placing the banking ball on the rail where it first touches the cushion or where it comes out after compressing and sliding down the cushion. I think the 2nd is more appropriate in measuring the actual amount of post-rebound bend. Again, our new procedure will eliminate the need for any judgement like this. Bob and I will try to post the new procedure and demonstration video within the next week.

Thanks again for all of your efforts.

FYI, I included your videos on the new version of the bending a bank shot resource page. If you would like me to include your real name instead, please let me know.

Regards,
Dave

 

[pool101]

Thank you for doing this. Our new procedure will make all of this much easier.

BTW, are you placing the banking ball on the rail where it first touches the cushion or where it comes out after compressing and sliding down the cushion. I think the 2nd is more appropriate in measuring the actual amount of post-rebound bend. Again, our new procedure will eliminate the need for any judgement like this. Bob and I will try to post the new procedure and demonstration video within the next week.

Thanks again for all of your efforts.

FYI, I included your videos on the new version of the bending a bank shot resource page. If you would like me to include your real name instead, please let me know.

Regards,
Dave

The ball on the rail is where it came out of the rail as best as I could determine. I should of had a camera looking straight down on the rail, but it happens so fast it my cameras may not have been able to capture it.
Mark

 

[Bob Jewett]

Here is a video with the measurements.
https://www.youtube.com/watch?v=Q78s5Hq88sA

Thanks for the additional info. I hope you try the challenge with the markers in place when you shoot the shot. It sure looks like more than an inch of bend is possible from your estimates.

Will you be at Derby City?

 

[pool101]

Thanks for the additional info. I hope you try the challenge with the markers in place when you shoot the shot. It sure looks like more than an inch of bend is possible from your estimates.

Will you be at Derby City?

I will most likely go for a while, usually for the banks. I am sure I had more then an inch, and I think a good banker like John can get more.
Mark