Bowling Thumb Pain: Causes, Gripping & Ball Fit

Question
On my bowling thumb, at the base of it on the inside, it cracks into a sore right where it hits the ball.  I haven't had this happen before with other balls that I have had.  Is my ball drilled right for my grip or is it how I am holding my ball?  The edge of the thumb hole is a sharp angle and not rounded.  Does this also make a difference?

Answer
Lacy,
Somethings causing you to hold/grip the ball differently. Take your and an old ball to the driller and have them check for pitches/span/hole size differences. The lack of bevel may also be a big contributor, if it is the primary problem, your ball doesn't fit as good as it could.

Thanks for your question. Good luck and good bowling.