[Jeff]

Mike - you state that you can think of the clubhead having angular acceleration, but you don't equally think that the clubshaft can have angular acceleration because you presumably perceive that the grip end of the club is not simply rotating around a"fixed" point in space.

The problem for me regarding your statements relates to the question as to where is the locus of the central point of the "imaginary circle" that allows you to describe the clubhead's movements in terms of having angular acceleration, while you are not willing to accept the idea that other parts of the clubshaft also have angular acceleration? You seem to be willing to entertain the idea of an "imaginary" central locus for the clubhead's movement, but you are unwilling to apply that same conceptual idea to any other point on the clubshaft eg. grip end.

By the way, I think that even if the left hand is moving at a constant speed during the release phenomenon, it doesn't mean that the grip end of the clubshaft has to travel at the same speed as the hands - because the left wrist is uncocking during the release phenomenon.

In nm golfer's explanation, the central hinge-point locus for the clubshaft's rotary movement is always at the hands - even though the hands have a constantly-variable directional movement and constantly-variable speed of movement. At each fractional moment in time, the clubshaft can develop angular acceleration with respect to its radial movement around the "instantaneous" hand-axis hinge point. In other words, the clubshaft has a circular motion around a constantly moving central locus hinge-point at all time-points during the downswing (even during the release of power accumulator #2) and all points on the clubshaft have the same degree of angular acceleration because the shaft is a rigid structure, but the clubhead's motion (or grip end's motion) relative to "any" locus point on the body is not circular, and cannot therefore be precisely described in terms of "angular acceleration".

Jeff.