Banking on Tables with High Speed cloth

dr_dave · Jan 21, 2015

Patrick Johnson said:
As Bob says, a sliding (not fully rolling) OB banks short. If you hit it hard (even from some distance depending on how hard), the OB won't be fully rolling when it hits the rail.

Other less-well-known effects are:

The rail hits the OB above center, which puts some cross-table topspin on it, which shortens the rebound. This effect can be easily seen if you watch for it, especially on harder shots - but I'm not sure if hitting harder makes it shorten more or just makes it more visible.

Because of less-than-perfect rebound efficiency, the rail absorbs some of the OB's cross-table speed, making it rebound longer. On the other hand, friction between the ball and rail reduces the OB's along-table speed, making it rebound shorter. These two effects occur on every bank shot (fast or slow), and counteract each other to some degree.

pj
chgo

Patrick,

It is good to see you back. Did your long ban just end? Are you going to be a "good boy" now after your "time out?" I hope not. :grin-square:

Concerning kick and bank effects, all of them are summarized along with supporting resources (videos included) here:

bank and kick shot effects that must be considered

For those interested, enjoy,
Dave

Patrick Johnson · Jan 21, 2015

dr_dave said:
Patrick,

It is good to see you back.

Thanks, Dave.

Are you going to be a "good boy" now after your "time out?" I hope not. :grin-square:

So many errors... so little time. Frankly, on a celebrity chat forum like AzB is becoming, if I don't get banned occasionally I start to feel like I'm doing it wrong.

Thankfully, the echo chamber forums (Magical Aiming Conversation and NPRubberRoom) seem to still be keeping the crazies more or less safely quarantined.

pj <- posting fast to beat the ban
chgo

fastone371 · Jan 21, 2015

Bob Jewett said:
Actually, this turns out to be mostly false. It is the lack of follow on the object ball on high-speed shots that is mostly the cause of the bank angle changing. If the object ball has time to get forward roll, the bank will go longer. This is easy to demonstrate.

That's interesting about the rolling object ball. I thought some people will shorten banks by using draw on cue ball. Wouldn't that create a rolling object ball and lengthen the bank?

Patrick Johnson · Jan 21, 2015

fastone371 said:
That's interesting about the rolling object ball. I thought some people will shorten banks by using draw on cue ball. Wouldn't that create a rolling object ball and lengthen the bank?

Only if the OB won't naturally be rolling when it gets there, and even then the tiny amount of roll transferred from a CB with draw probably won't make a noticeable difference.

It might be more likely to shorten the bank - if using draw causes you to hit the shot harder, eliminating the roll the OB might otherwise have picked up.

pj
chgo

fastone371 · Jan 21, 2015

Patrick Johnson said:
Only if the OB won't naturally be rolling when it gets there, and even then the tiny amount of roll transferred from a CB with draw probably won't make a noticeable difference.

It might be more likely to shorten the bank - if using draw causes you to hit the shot harder, eliminating the roll the OB might otherwise have picked up.

pj
chgo

So it is more the speed that shortens the bank rather than the actual draw on cue ball? I do not hit many banks this way, I prefer to hit ball at pocket speed and slow roll banks whenever possible, always had best luck pocketing banks this way.
By rolling ball I am assuming you mean just rolling and not top spin. I always kind of assumed that you can transfer pretty good roll to an object ball where you have shots that you follow your opponents ball with your ball in same pocket on same shot. Its a pretty easy shot if you can make both object balls hit pretty square, even with first ball a few inches from pocket. (I am not being a smart ass, these are legitimate questions I have, FWIW.)

Patrick Johnson · Jan 21, 2015

fastone371 said:
By rolling ball I am assuming you mean just rolling and not top spin.

Just rolling is pretty much all the top spin you can get, on the object ball or cue ball.

I always kind of assumed that you can transfer pretty good roll to an object ball where you have shots that you follow your opponents ball with your ball in same pocket on same shot.

You can transfer a little forward spin, maybe enough to get the OB rolling a few inches sooner, which could be helpful on short follow-in shots like that.

pj
chgo

dr_dave · Jan 22, 2015

Patrick Johnson said:
Just rolling is pretty much all the top spin you can get, on the object ball or cue ball.

For people who aren't convinced, see:

natural roll, maximum offset, and overspin

Enjoy,
Dave

ssbn610g · Jan 22, 2015

This is great!! Thanks everyone.

It's funny how human's can build a model that seems to work for them but upon some real research find that the model they build just works through happenstance.

I will catch you all on the rebound!!:grin:

Al

Banking on Tables with High Speed cloth

dr_dave

Instructional Author

Patrick Johnson

Fish of the Day

fastone371

Certifiable

Patrick Johnson

Fish of the Day

fastone371

Certifiable

Patrick Johnson

Fish of the Day

dr_dave

Instructional Author

ssbn610g

AzB Silver Member