I hadn't planned on getting this deep into this thread, but there seems to still be, in my humble opinion, a lot of misinformation and false premises being argued. If you haven't viewed the 3 stone 8s on the link I posted, then please don't bother replying to this post. You probably won't be able to visualize what I'm talking about if you don't.
For years (as long as I can remember) other coaches, tv commentators, great bowlers and general students of the game, including myself, have said and believed that a stone 8 is left because the ball chops the 5 off the 8. Many still do. My friend, Mark Estes, former PBA member and student of the game and film collector, posed to me that the stone 8 was instead left because of the headpin knocking the 5 out of the way before the ball could contact it, therefore eliminating the pin whose job it is to knock down the 8. I started studying slo-mo replays of stone 8s left on tv and all but one that I taped was left for this reason. The one that wasn't had a 5 pin and 8 pin noticeably off spot. The videos on the link show it very clearly. Any contact the ball makes with the 5 pin is too late (5 is past the
to knock it into the 8. But, that's why the pin is knocked to the left, albeit too late.
Remember, we are talking flush hits here...with the center of the ball resting on the 17.5-18 board, not the 16-16.5 board, as shown in the 8-10 leave with a plastic ball. That's not the same thing. We're talking flush or stone 8 pin leaves, not flat 8s or shaker 8 pins or lefthanders leaving 8 pins. If the ball is centered on the 17.5 board, regardless of weight, you're going to strike, barring a stone 8, or possibly a 7 or 9. Even a lightweight ball or plastic ball will contact the 1,3,5,9 and the other pins ususally do their job on such a hit. Lord knows, we had lots of flush strikes in the 70s and 80s with plastic balls.
I inquired with USBC a few weeks ago about this very topic and surprisingly, the person I talked to knew of no USBC film bank or video with public access that could prove or disprove the point I was making to them. Mark ran across the link I posted and it backs up what I had been seeing in my own research.
Bob Hanson is right that we used to leave them in the old days as well, but I still think there are more of them now, due to the fact that I think today's lane conditions funnels more balls to the pocket...therefore causing a higher number of flush (17.5-18 board)hits. I don't think you can or should adjust for them, just accept the fact that the person who hits the pocket the most is going to leave the most. Watch the videos again. Especially the 3rd one. You can see the headpin between the ball and the 5 pin, then deflecting (the headpin) around the 8 pin. Here's the link again:
http://www.teamstatpro.com/solid8pin.htm
