The bowling hand and the stress and demands we put on it during the game of bowling (both hands if you’re a two-handed bowler) can be more than imaginable.
Most pro shop operators get asked many times a week, what should my hand(s) feel like as I hold my bowling ball through the entire swing and release? If your bowling ball is drilled correctly, you should not feel very much fatigue at the end of a normal league night and three games of bowling. If you bowl tournaments that require many more games in just a couple of days/weekend, you may have to deal with blisters, puffing, stiffness and even joint fatigue—especially if your hand, arm and legs are not in shape!
What you should be feeling in your bowling ball, regardless of conventional or a finger-tip grip, is a smooth edged thumb hole that requires little or no squeezing at any part of the swing and releases quickly when you totally relax your thumb at the release point.
Fingers next. As your thumb exits the ball, soon after the fingers should also exit without much drag. There are a few exceptions for bowlers that use a full stretched finger-tip grip. Often they feel a burn or tingling sensation on the pads of their fingers.
Sounds easy so far, right? Do you release the ball in a handshake position? Cranker position (up under the ball)? Stroker position (behind the ball into a handshake) at the release point or maybe a back-up ball? All of these different angles of release require different thumb pitches (angle) in order to not put your thumb in a bind as it exits the ball.
Ask a friend where your thumb is at the bottom of the swing and as it exits the ball (video in slow motion). Have your ball driller give it a look also.