I have bad arthritis in my fingers that forces me to use a lot of away in the fingers so I find the forward pitch very useful for getting the ball over the foul line.

I didn't notice any appreciable loss of revs when I changed over from reverse to forward pitch. I'm no cranker, just a tweener, but a tweener was all I was with reverse pitch in the thumb. The only problem I've had is I sometimes don't get out of the ball as cleanly as I'd like. I plan to reduce the amount of forward pitch to see if that improves.

Lefty why is the 63 degree angle the magic angle?

Jerry,

Seriously, to elaborate a little one what I said while rushed last night.

One must first understand what the angle 63 degrees is.

It is the angle from the top front lip of the fingers drawn straight to the front edge of the thumb hole.  This is a straight line drawn straight thru the ball.

This angle applies to both conventional grips and fingertip.

In other words a person who uses a conventional grip of 3 1/2 would use a forward thumb pitch of about 3/8 forward.  That same person going to a fingertip of 4 1/2 inches would use reverse of 1/8.(per the tables).  Note same person different thumb forward/reverse pitches.

The assumptions in all of these is that the fingers are set at 0 forward reverse pitch.

If one goes dramatically forward from these tables it makes the same span feel longer.

I believe that in a case like yours where reverse is added to the fingers corresponding forward in the thumb compensates.  In other words reverse in the fingers makes the span feel shorter, forward in the thumb makes the span feel longer!  Offsetting feels.

Going back to the 63 degree question.  A 6 inch span bowler forward reverse pitch ends up being 7/8 reverse.  A 4 inch span bowler forward reverse is 1/8 forward.  Both of these are 63 degrees.  The 6 inch bowler finger thumb line cuts thru a lot of the ball the 4 inch span hardly cuts thru any.

Regarding my comment that the 63 degree angle can be seen hold your hand and position it so that you can look at it from the side.  Position it in such a way that it is in the air with your wrist near a straigh position but could fit in your bowling ball.
You will note that your thumb naturally assumes a position that is not perpindicular to your palm (90 degrees) and it is not forward enough to be 45 degrees.  It is somewhere in between.  Around the middle of these two angles.
About 63 degrees.  (the actual mid point is obviously 67.5 degrees).

Bill actually did empirical tests with bowlers and found these angles that seemed to induce hold but then clean release.  They work for most people with slight variation!  Usually 1/8 forward or reverse off of the tables.

REgards,

Luckylefty

To elarate a little more on this subject.

I also find that round thumbholes allow me to have more reverse than my ovals.

The round thumb holes give me more holding power and therefore for an example.

With an oval grip I may for a 4 5/8 span have 1/16 on a reverse versus for round I will use closer to a 3/16 reverse.  The 1/16 causes me to hand with a round thumbhole!

REgards,

Luckylefty