So lately, I've come into a bad habit of gripping the ball with my thumb.  I find myself bending my thumb during my backswing because I feel like I'm going to lose it.  I've been working on not doing that, and when I loosen up my ball reads the lane loads better.  My question is, do you know any exercises or methods I can try to completely rid myself of this gripping thumb?  I tried to put a boatload of tape in to make the thumbhole small enough that I CAN'T bend, but I still notice I'm doing it.  It helps with the cleaner release, but it's not helping with gripping.  Any and all ideas will be very much appreciated.
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Proud Supporter of Rob Stone
Obviously, you aren''t a golfer.
Some stayed in the foothills, some washed logs like teeth.