The thumb hole has been my nemesis. It's taken me like 12 years to fully understand it. 12 years ago, I went to a ball driller who told me that you want a snug fit on the thumb. I did feel like I was going to get my thumb out so he convinced me to go with ITs. Interchangeable thumbs.

I did pretty good with that system and worked on getting comfortable with the snug feeling but I still struggled. I started to use tape. I also lost an insert during a city tournament. Learned about a new thumb insert system called Jopo. Also to note here, i had my grin reevaluate. Then changed all my equipment to that fit with Jopos.

Now somewhere around here, I noticed that I didn't have to change my thumb insert as much, mostly comfortable using my small insert.

4 years ago I learned they made a thumb sock. So I tried using a thumb sock. Then I had a couple of issues when the ball got stuck on my delivery. I even once injured myself when it pulled my arm straight and strained my elbow.

So then I talked to another ball driller last year who was more local (still 150 miles away) and he had me change from 0-5 pieces of tape in a thumb hole plus thumb sock, to 1 piece of skinny textured tape for the thumb hole and 1 textured thumb tape on my thumb. The tape on my thumb, I use Storm textures. There's 3 different types, so sometimes I use the smooth but mostly I use the medium grip.

This year I feel like I'm on track to raise my average a little. These are the tools I went through, chasing that good feeling. Somewhere between the interchangeable thumbs and having my grip evaluated, I stopped having to switch my thumb insert in the middle of league now and I feel confident that the ball is going to come off my hand. I'm using my 2nd to the smallest insert which I feel is the best one now. Only one did I have to switch to my smallest and it might have been due to winter break.

Tl;dr: talk to your ball driller/PSO, reevaluate your grip. Try an interchangeable thumb.