Right handed guy throws a plastic ball at the 6-10 & states he either chops off the 6 or the 10 a lot. He has brought up the idea of trying to throw a back up ball at the spare.

Bowler has Fwd & right for his current thumb pitch.

My question is: should one change pitches when having a ball drilled to throw a back up ball? Having right may not be a problem, just wondering if the Fwd would be an issue for him? I personally would like to look at his plastic ball, but he is very set on trying the back up ball thing & brought in a tropical freeze to be plugged & re-drilled.

To throw a back up ball the hand has to be either behind in line with the arm or on the inside closer to the body to allow the hand to rotate counter clockwise (for a right handed bowler)
If you place your hand and arm in this position, look where your thumb naturally goes...it should be pointing away from the body or left lateral

If a bowler delivers a bowling ball somewhat properly, where the hand is all that happens is rotation around the equator and a back up ball is actually easier

Releasing a bowling ball normally causes damages to many places on the body there is nothing natural abt releasing a bowling ball