How much should my thumb slip during my delivery. My thumb slips some but there is no fear of the ball falling off at all.. If I let the ball hang at my side my thumb slips a bit and the base of the thumb grabs at the front of the thumb hole and the back of my thumb tip holds farther down in the hole. It is the angle of the thumb and these two points that keeps the ball from falling off.. Is this how it is supposed to be ??

I can also just put my thumb in the hole with out any fingers and swing the ball without fear of the ball falling off.. am I good

Your thumb shouldn't slip at all on your swing. It should fit securely and snug on your thumb. It sounds like you feel it slip when you relax your hand (which is a good thing). However, since it sounds like your thumbhole is off it sounds like you have the same problem I had in grabbing/clenching the ball (which is a bad thing).

I do a very simple test to see if my thumbhole is right as well as to see if I need some tape in the thumbhole and where. You could try it, I mean I got it from Mika Koivuniemi at a clinic.

What you do is sit the ball on a surface it will spin on, stuck your thumb in the ball, and spin the ball. The ball should grab your thumb and tweak your twist your arm around with it. By no means should the ball be rotating around your thumb freely. And I spin the ball both ways to ensure the best fit possible.

I will try that.. I don't think the ball will spin all the way around my thumb but I'm sure there will be some play.. I know that I use a thumb hole that is looser than it should be. I have a long thumb and have trouble clearing when my thumb is super snug.. I used to have a ton of reverse .. now I have the standard 3/8 reverse for my span of 5 inches... I still have a good deal of bevel.. I need to experiment with some different tapes.. I used to only put the white tape in the front so I had the smooth hole in the back.. I could get that pretty tight and still come out.. now I just have one piece in the front for grip and do all the size adjustment in the back with white tape.. I think the white tape in the back is too much grip when the hole is tighter.. I've been thinking about trying the magic carpet or someother thumb hole product..

Get Ebonite's black tape for the back of the thumb hole.

When you put your thumb in the hole, it won't be locked yet. It doesn't lock until it pulls out a little bit and the ball grabs the webbing of the thumb. So if you put your thumb in all way, and never pull it out a bit until the swing starts, you will have it slip a pinch before it locks. I like to put my hand in and then pull on it a bit to get the lock before I set myself in my stance. Wes Malott gets his ball to lock as part of his pushaway. There are probably others that do it somewhere between. Find what's comfortable for you. To me, the earlier the better. I would not want to do the Malott way and find out too late that I hadn't gotten it locked properly.

I have developed a habit of bouncing the ball on my thumb while I am holding it in my approach. The reason is to completely seat my thumb in the hole. I find if I don't do that, and the thumb is the slightest lose, I will grab with it.

ok.. so how much should it move out before it locks on the webbing.. mine is definately catching the webbing . but it is also catching the backside tip of my thumb as well and kind of wedging my thumb from coming out. When I put the weight of the ball on my fingers then my thumb can freely rotate out of the ball..
is this the way it is supposed to be.

If your hand is under and behind your ball, your thumb should come out freely. If you have your hand over the ball at release, your thumb will grab or grip.

When you pull your thumb out a tad and it locks do you keep it in that position or insert it all the way again? I'm led to believe that it's the former since pushing it back down will make the lock go away. At least that's what I think happens(just tried it).

I am standing here looking at a release and it almost looks the opposite for me.. If I leave my wrist cocked and behind and under the ball it is tough for me to get my thumb out.. when I release my wrist that is when my thumb seems to want to come out freely..
when my thumb and thumb hole are pointing straight down.

just looked at it again.. maybe not.. it is hard to do it without actually swinging and releasing the ball.

I went from a stretched span with alot of reverse to a more correct span.. I think the longer span and reverse helped pull my thumb out of the hole .. I'm almost thinking I still need more reverse to get out clean.
If I have a looser thumb hole I seem to be able to get out easier.. If it is tighter I have trouble clearing the hole.
I think my thumb is longer than most at 2 3/4 inches. I don't know if that has anything to do with it.

The forces going on at the bottom of a 17 mph swing are much different than the forces going on when you're standing there swinging. When I put my thumb in the ball, it feels like there is no way it can possibly come out. Just listen to the pros after they balk, and take their thumb out of the ball. They have to pry it off their hands.