Based on what you just said, I bet you've burned a nice track onto them (especially because you're using them on wood lanes). If you're right handed and look on the left side of the ball as you're looking at the holes, there's probably a dull spot where the ball has been rolling. With all of those games on them it should be easy to see. It looks kind of like a bow tie as you follow it. This will cause the ball to roll earlier and turn and hit flatter because the balls aren't storing enough energy to turn the corner like they did before. Either buy some polish and do them by hand or go to the pro shop guy and ask to have them polished and that should solve your problem. Based on your usage and what kind of surface you're bowling on (wood), you should probably polish them weekly (every 2 weeks at the least) to maintain the surface of the bowling ball, which will maintain the ball reaction.
Best of luck
Edited on 1/10/2007 3:02 PM