I just wanted to comment a bit further about this discussion. I think that there is room for many perspectives, especially that of living bank pool legend John Brumback as well as the expertise of Dr Dave. As I see it, we get the best of both worlds here: a wealth of practical knowledge and the perspective of how to "sense" the shot and on the other side of the spectrum, the attempt to replicate, document, and explain and share the phenomenon from a scientific perspective. This means that we all win, imo.
I can personally vouch that JB can make a player better and I think that Dr Dave's high speed videos and more are awesome as well.
Chris,Brumback busted you on spin transfer and he will bust you on curve
Dave,
I'm sure you realize that i bust your balls because it was ludicrous when you were writing Billiards Digest articles, pontificating like an expert and...you shot like a rank beginner.
Anywho, i have a suggestion for you...why don't you enter a regional tournament and see how you do? You know, drill scores are great and all, especially if you practice the same set up over and over until it's perfected, but at the end of the day, don't you want to know where your skill level is, in the *real world*?
Eric
All I can judge is whether someone helps me to play. When I read Dr. Dave's stuff, I can usually go to the table and try it, replicate it, and learn from it. I don't care how good someone plays in tournaments, if they say mysterious things on forums that I don't understand or can't replicate on the table, it means nothing to me.
I learn things from everybody...even their mistakes. I then try to replicate what they did or avoid doing what they did.
Some people need scientific instruction to learn things and others can learn simply by watching and receiving simple instructions.
If I stood behind John and watched him bank a shot or two, I think I could replicate it without going to pool school or reading a scientific breakdown of what happened.
That doesn't mean I wouldn't want to read the textbook or watch the video. It just means some people learn things differently and come to the same result.
All I can judge is whether someone helps me to play. When I read Dr. Dave's stuff, I can usually go to the table and try it, replicate it, and learn from it. I don't care how good someone plays in tournaments, if they say mysterious things on forums that I don't understand or can't replicate on the table, it means nothing to me.
Also, the ball compresses the cushion and slides down the rail during rebound. That's why I started the line with the OB off the cushion a bit. That results in a better measure of the actual curve after rebound. Another thing we need to be careful with is the effect of the airborne CB on camera perspective. If the camera angle is oblique and the CB hops, the 3D perspective might fool us into thinking the ball is curving more (or less) than it actually is.
I will try to shoot some video tomorrow with two cameras ... one a view similar to John's, and another looking straight down the rebound path. I will also try different angles and speeds (but mostly fast) to see what is possible on my equipment.
Regards,
Dave
PS: I would have shot the video today, but I decided to dedicate the day to improving my BU Exam II score. I managed to improve my PR by one point, but I was still 4 points shy of a perfect score. I won't rest until I get a perfect score ... I think it is quite possible on the Masters-level Exam II. I think a perfect score on the Doctorate-level exam would be a lot, lot tougher to achieve, even for a top pro. I'll post the video on the AZB BU sticky thread after I get it edited and uploaded.
Lou not to stir the pot but I think I have the opposite opinion on this as most of the bank players seem to not want clean conditions. They want the balls dirty as they can get more bite transfer more action to the OB and get more action on the OB from the rail. I think the best player play the hooking bank, more now than a couple of years ago as John shared the basics of this concept on his great DVD. I know some champions took that DVD home last year and banked better at the Derby this year.
About real clean equipment, they slide more every where no bite. Spin stays on the balls longer across the bed of the table. Using truly clean balls and very clean cloth the balls hit the rails and slide out dead very noticeable. Bankers never ask to clean the balls that I have seen. They seem offended at times when the balls are cleaned prior to a match.
I think the equipment conditions can be used to manipulate the results get more action. An example I know of was Bugs when he used to play, he used alot of powder he had the table dirty in hurry. I doubt that was unintended.
Would like to hear more on this aspect from elite bankers.
I graphed out the path from that analysis software. This broken apart so it shows the X and the Y separately. Definitely is curving and it curves the whole way across the table not just by the rail.
...
I agree that to get a noticeable and potentially-useful amount of post-rebound curve, the cushions need to really grab the OB (to impart topspin and masse spin as the OB compresses the nose of the cushion both forward and sideways). It might also help for the cloth on table bed to be slick (to limit how much spin is lost when the OB is driven down into the table off the cushion, and to delay the post-rebound curve so it is more noticeable).Lou not to stir the pot but I think I have the opposite opinion on this as most of the bank players seem to not want clean conditions. They want the balls dirty as they can get more bite transfer more action to the OB and get more action on the OB from the rail. I think the best player play the hooking bank, more now than a couple of years ago as John shared the basics of this concept on his great DVD. I know some champions took that DVD home last year and banked better at the Derby this year.
About real clean equipment, they slide more every where no bite. Spin stays on the balls longer across the bed of the table. Using truly clean balls and very clean cloth the balls hit the rails and slide out dead very noticeable. Bankers never ask to clean the balls that I have seen. They seem offended at times when the balls are cleaned prior to a match.
I think the equipment conditions can be used to manipulate the results get more action. An example I know of was Bugs when he used to play, he used alot of powder he had the table dirty in hurry. I doubt that was unintended.
Would like to hear more on this aspect from elite bankers.
The graph you show looks like x and y versus time. You need to plot x versus y with time as a parameter, not a variable, in order to see a curve. Apart from that, it looks like both |dx/dt| and |dy/dt| are increasing, for example around t=141 (milliseconds?). This would be quite remarkable.
Barring camera distortion and possible bouncing, I agree. Can you extract the direction and magnitude of the acceleration?Bob you are right. I did an XY scatterplot with a smooth line in Excel took a screen shot put that shot on the left. The plot on the right is the exact same image except I drew a thin straight line in paint so we could see the curve. Definitely looks like a curve to me ...
Barring camera distortion and possible bouncing, I agree. Can you extract the direction and magnitude of the acceleration?