Expert: Chip Aki - 5/30/2005

Question
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Followup To
Question -
I have enjoyed bowling for many years and have problems with getting my thumb to come out of the ball smoothly. I use classic form, square to the lane and pendulum swing, avg 180's. Recently allowed a couple of amateurs to drill my ProZone and now it is available for experimenting. When I put only the thumb in, it comes out easily but when I set the fingertips and roll the ball as if releasing it the thumb is caught at the top on the inside and the knuckle against the outside of the hole. The knuckle isnt rubbed raw it just delays the release and I lose power, drive, leverage (whatever term is correct) and it hits like a marshmallow. Leaving the 5 pin is such a sissy thing. A shorter span makes the fit sloppy and uncomfortable harder to control. The guy who last drilled it said the thumb is drilled 0 side to side and 3 3/8" reverse, (I think, was not listening very well at the time). Have you done any experimenting with the angles of the thumb, any recommended limits or ways to guess what might be best for me?
Answer -
Forward and reverse pitches in the thumb are related to the length of the span.  Lenght of the thumb and dampness of the skin can come into play as well.

What span are you using?

Chip


I have never investigated the art of ball drilling but measuring from the edge of the thumb slug to the finger insert is 4 3/4" on the ball I am having problems with. My other ball (TI messenger) measures 4 7/8".  Odd, that is not what I expected to find. Both balls have the same size finger grips: ring finger 11 and middle finger 23. Don't have the gizmo to measure the angle but I set the ball with the thumb hole as near to top center as possible and ran a ruler down the hole on the side toward the fingers and I can't see any difference in the two balls.

Lonnie

Answer
On average, the longer span would have more reverse pitch in the thumb hole than the shorter span.
What makes this hard to diagnos is all of the variables that go into fitting that I cant see on the computer.  If you have too much reverse, too short of a span, or to big of a thumb hole, you will have to squeeze the ball and this can cause you to hang up.  I would make a guess that the one you have trouble with is because it is shorter than the Ti messenger.  If the pitches are the same, then the shorter span will be harder to hang on to.  The shorter span would need less reverse pitch.
To check the spans, place your thumb in the thumb hole and lay your fingers over the finger holes.  The gripping edge of the grip should hit halfway between your first and second knuckle.(counting from your tip of your finger)  
Fingertips used to be drilled much longer than that so if you havent changed your specs since you first had a fingertip drilled, you may have a longer span and that is why the shorter one feels so bad.  With proper pitch changes, the shorter one would be fine.

Good luck,
Chip