I saw the video below and just loved it.
Yesterday I was bowling with a nice couple of teammates after league. He's fast and direct but 1/2 of the time it looks like his thumb gets hung and his shoulder pulled forward (head pulled down when that happens also) and he loses all his hook when he hangs.
We discussed a stable shoulder and head and free swing around the stable pivot point of the shoulder. We all worked on it. Me with a pretty high ball speed day for myself.
This bowler is the one of my all time favorite forms on Youtube.
http://www.youtube.com/watch?v=dvUcAqX7QYo Note the displayed steady head starting at the 55 second mark.
Free and fast armswing around a very stable pivot point shoulder. An absolutely steady head with no bobbing down from a slightly hung thumb nor any lifting up of the head or upper body. Lots of free speed combined with balance.
Probably a bowler on this site. Form I would like to someday see for myself! At least while still a one handed bowler! Striving!
REgards,
Luckylefty
PS shades of the freedom of swing of all time great Dave Davis