I experimented today with a long left thumb (I'm righthanded), stretching it down the handle under my right hand.
this as opposed to keeping the pad of the thumb closer to the heel of the hand.
Long thumb seemed to make it harder to release; BUT allowed a sharper lag angle between the club and left arm at the top of the backswing.
Am I assessing this correctly? Will a long thumb move the ball flight left or right, cause blocks or hooks?