[Jeff]

Mike O

I don't have a precise knowledge of physics, so my use of the term 'angular acceleration' may be incorrect. However, if you look at the hand arc and clubhead arc in the Bobby Jones photo, and look to see how much the hands move per unit time relative to the clubhead movement per unit time, the clubhead is moving a greater distance than the hands - and the clubhead movement per unit time is increasing progressively as the downswing evolves (even though hand speed remains relatively constant). Therefore, I perceive that the clubhead is developing angular acceleration and that this represents the release phenomenon.

Jeff.