I know I should have done this earlier but just haven't.  I've been bowling for about 7 years, carry a 212 average with a 300 and multiple 279 games to my credit.  My problem is I have no clue about drilling a ball.  I have a pro that does all my drilling and I've been happy with the results but feel that maybe there is some unlocked potential hidding there.  Does anyone know of a good place to find information about how and why you drill a ball a certain way, keep in mind that like I said, I'm clueless, so the more basic the info to start with would be better.  Thanks.