Have been a full roller for long time, but would like to change to semi. Have tried on my own with no success. What is the first step required to make the change? I will be seeking out a coach to help, but would like to at least take a step in the right direction first.

A) Keep your hand (fingers and thumb) behind the ball until it gets to your slide ankle.

B) Make sure the thumb exits the ball first. Don't turn the fingers to the side of the ball until after the thumb starts to come out of the hole.

Welcome to the site, I see you are in MD, what part of MD. I coach at Bowl America Gaithersburg if you are interested, just let me know.

First what happens to get the full roller is the hand is on the side of the ball then the fingers rotate clockwise at the release, this sets the thumb outside of the fingers. If you rotate the fingers counter clockwise (right handers, clock wise for lefties although I can count the number of full roller lefties on one hand)the thumb will go inside of the Track and you will have a semi roller.

Welcome, Ironman. Are you sure you are a full roller? If so, your oil Track should be between your thumb and fingers. That is caused by your release. Now, I see quite a few full rollers, as it was the predominant method years ago. But, very few of these bowlers have their ball drilled appropriately for this. Drillers don't see enough of this today, and generally don't get it right.

A true full roller drilling should have the pin on the middle finger side of the grip. If it is not, your release acts contrary to the way your ball wants to roll. Check that first.

Welcome to the site Ironman80. The others have given good advice, none that I can add to. This transition would probably be easier seeing a coach in person though.

If you are right handed practice holding the ball with your middle and ring fingers at 6 o'clock and turning the ball counterclockwise to 3 o'clock when releasing the ball.

The above is counter to a full roller release in which you may start in a "handshake" position with the fingers at 4 o'clock. However when releasing the ball, the hand moves clockwise instead of counterclockwise resulting in a full roller.

If you have an old chair a home you can practice turning your hand in a counterclockwise direction at the release point. Remember that the turning is done with your arm, not your wrist.
You are driving your fingers through the ball, not around it.

Also, if you haven't done so already, have your thumbhole drilled with under the palm pitch - 1/4" maybe. Under the palm pitch will help you turn the ball counterclockwise.

Coach Jim I live near Columbia and I would like to contact you and see if you might help me with this.

Dennis, thanks for the response and yes I am a full roller. The Pro Shop I use knows this and drills for correctly. But you are correct as the previous Pro Shop did not.

JohnW1 thanks, I will try turning my arm. But I think its time to see a coach before I have the balls redrilled.

Cgeorg thanks, I do believe that am late getting the thumb out.