I've been league bowling for about 4 months now after not bowling for 10 years.  I'm on a Tuesday night and Thursday night league.  On Thursday, I couldn't get my thumb out of the ball.  Is it possible that my thumb is getting bigger from getting back in the game or that it was just a fluke this week.  I shot crappy, and at the end of the match, I was only partially putting my thumb in the ball.  This is the first week I've had a problem like this.