QUESTION: Here are the photos of the 2nd ball
Urethane Storm Polar Ice? Looks better spanwise. Angles are hard to tell. I'll leave more info in my other post.
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QUESTION: I tried holding both balls by my side with a relaxed grip. In both cases, my thumb would start slipping out of the hole until it completely left the thumb hole. (Of course, I held the ball only a few inches of the floor for this test.) If all things were perfect, should I be able to hold the ball like this indefinitely. Perhaps this means I need some grip tape?
Could it also be that my thumb is not clearing the hole as I release the ball thus the ball is turning around my thumb and, since the hole is oval, doing so would put a lot of stress on the thumb?
The ball should hang in your hand. The angles of the holes should facilitate NO grip pressure. The thumb hole should accommodate a little wiggle room. If a piece of tape or two solves the problem, your good. But, if the tape isn't all you need. You can tighten the holes but it's dealing with a symptom and not the problem. Unconsciously, you're grabbing the ball and that's the callus and the pain.
The oval thumb should guide the ball off exactly the same way each delivery. If there is an additional angle issue with the lateral pitch, you can try to address that by trying to adjust the pitch angle both more forward and in the direction of the rubbing on your thumb. Do you know if you have away pitch in the finger holes? Are your fingers stiff?
Looking good. I think we've identified the need for a thumb angle change, that should accomplish ridding you of rubbing and pain. Mention to your driller maybe he'll want to check out AllExperts and make a donation! Thanks for the questions. Anything further, check out my website: www.revbowl.com and drop an e-mail.