I'm currently at 3/16 reverse and feel like I have a hard time keeping the ball on my hand throughout the swing and at release.  I just had a new snug 3/16 reverse, a 1/16 reverse, and a 1/16 forward switch grip thumb drilled so I can experiment.  I hung up on all of them until I opened the top of the thumb a bit and added bevel.  The 3/16 reverse required a minimal amount and the 1/16 forward required a little more. Nothing extreme but I did need more so that I could be confident I would get out of the ball.  Now that I can clear the thumb it feels like the ball comes off too fast at the bottom.   I do like that the ball stays on my hand better throughout the swing.

This is the most forward I have ever been.  Until I drilled my new equipment I was usually at 3/8 reverse

Should I go more forward and just open the top and bevel the thumb until I can clear? 

Thanks for the reply.  I have recently shortened my span for the very reason you are stating.  I was at a 5 1/16 inch span for the longest and just went down to 4 3/4.  I had always needed at least 3/8 reverse to get out of a ball.  The bevel that I have now is not excessive, but it is more than likely because I was dragging on the front edge of the thumb.     My thumb has never rolled right into the hole.  I would always have to crook it around the edge to get into the hole.  With the 4 3/4 it feels like it goes right in, at least more than it ever has.  I will re-evaluate my span to see if I need to go even shorter.


I do have one question.  With my shortened span now I am getting some callusing on the top back of my thumb and on the left back side of my fingers.  It looks like this is due to the fingers being in contact with the back side of the inserts where before they were stretched and never made that contact because they were being pulled away.  What is your take on that?  I'm at 3/8 reverse in both fingers

You have any reverse in your fingers?  Might add some. 

Always go the ditection the wear...thus if you're at 0 & 3/4" (which is excessive at best) I would prolly go more like 1/4 & 3/8" and see what that does
You're making a lot of changes and this can create confusion...you need a valid starting and then make adjustments from there...

I PMed you back (:

If the callous is on the flat of the thumb and is new since you changed to less reverse adding a slight amount of front bevel using the Mo Pinel bevel tips could solve everything.

For the always thinking Gizmo.  A thought to consider.
As to always having the thumb fall in to the thumb hole when the ball is resting on the table....well there are other bowlers with very flexible hands who while bowling their hand seems to lengthen as the ball weight comes on to the fingers. 
I am one of those flexible bowlers.  Many very experienced ball drillers often suggest I go a little longer than I currently am which has the thumb hole about 1/8 of an inch longer than having my thumb fall in to the thumbhole while the ball is holes-up on the drilling table.

If I use the fall right in to the thumbhole method suggested in posts above...
If I only go that length the back of my thumb often feels while bowling that it is hitting the back of the thumbhole.


I do believe there are many bowlers with much less flexible hands than mine!

Regards,

Luckylefty

Sounds like span now too short....but....

I have never gotten to that point but close....  When I have my thumb go straight in!

Regards,

Luckylefty

JustRico,

So to accurately interpret your post.

All balls with any amount of bevel are wrong?  Span and pitches must be adjusted?  Why is having NO bevel important?

That seems like an extreme position. 

Please clarify?

Thanks,

Luckylefty