Do I dare ask what weight of ball you are throwing and what your mph number is? The lighter the ball the less dense the mineral filler between core and shell, and the greater the chance of cracking the faster you throw it. If it was just at the bridge I would say use less super glue if you use inserts. Finally, if you have trouble with your thumb hanging you may have the ball tracking over the holes and hitting the pins with the drilled areas which are the weakest on the ball.