Hey everybody, I come seeking advice on proper thumb fit. I've been fidgeting with a grip for a while now. I have a super flexible thumb, and it's been a bit of a challenge to get a grip that feels 'perfect.'

Currently, I'm working on thumb shape. I've been using a mold that's got some room to add/remove tape as needed. I use a tiered taping style because my thumb tapers quite a bit. I'm testing two new shapes. Both are rounder, and both are snugger than the mold - one is really snug, and the other is somewhere in the middle. Also, both of these new shapes have less bevel. Both of these thumbs make the ball feel lighter, and actually help me 'throw it over the towel.' Last night, after rolling a set with the in-the-middle thumb, I rolled some practice with a molded-thumb and was dropping the crap out of it. There was no throwing it over the towel unless I grabbed it.

This prompted the question - what does a proper thumb fit feel like? What do you guys look for in a thumb fit? I understand this is a subjective topic, and I am indeed working closely with my PSO - I'm just looking for different perspectives on a this rather fascinating topics.

Thanks for this input, notclay. I think your point about too much bevel vs. the proper amount is waaaay more important than I ever realized. I have never had a more secure fit than I had last night. I was actually able to loft the ball whenever I wanted!

That's wild, SVStar! I have been toying with my finger pitches as well, but not quite as much. I injured my fingers in separate incidents (broke my middle finger playing softball, and tore the ligaments in my ring due to a terrible ball fit when I was a teenager). This limits me from trying too much one way or the other.

Are there any big names for ball fitters? Maybe I'll travel to a guru and see what new ideas there are that I could try.

Hole size
Hole shape
Pitch
bevel

The thumb hole should be tight enough to have good security in the ball.  For some people, this can be accomplished without tape.  For most it will require tape at some point, either on the skin or inside the thumb hole. 

Shape is created via having an oval or ovaling with tape.  If one ovals with tape, the tape needs to be positioned properly in the hole in front/back/side of the thumb. 

Thumb pitch is measured off of a couple of variables.  Web flexibility, Skin texture, span length, thumb length should all be taken into account when determining the proper thumb pitch.  Plus lateral pitch is measured off a fitting tube.

Bevel is personal and helps promote clearing the ball faster/slower. 

For my thumb hole, I drill a 61/64 full depth, a 31/32 3/4" then 1 3/64 1/16 of an inch.  Then I smooth the thumb with a scotchbrite.  I don't use sanding discs at all on my own equipment.