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.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.
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.
Again, that is exactly what we are doing with the modified challenge.It would be interesting to modify the challenge to "who can bend the ball the most"?
Thank you for your input,
Dave