Same here, I agree with John P. Plus, I find with alot of my customers, excessive forward leads to bad habits. Usually in a sequence like this:
1- Follow 25 year old drilling instructions and pitch to span conversion charts without using your own flexibility and measurement checks yourself.
2- "This feels funny, the thumb feels too tight, it won't come out. Can you open it/bevel it more?"
3- Hole gets opened up for them to clear the hole with their excessive squeeze at the knuckle due to an oversized/overbeveled thumbhole.
4- Their release becomes more of a pitch out into the lanes instead of a roll.
5- Lessons and excessive plug/redrilling/reslugging is needed to correct a bowler's performance due to a standardized gripping assesment being used.
I always go with my gut instinct and my own flexibility and span checks for every customer at every age with every span. There's something about everyone that is going to be different when you account for that person's hand.
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-DJ Marshall
...The Twelve In a Row Pro Shop. Hyattsville, MD
Coach: University of Maryland Baltimore County Mens Bowling
