[Jeff]

nm golfer - you wrote with respect to my diagram.

"Precisely... all club parts rotate at the same angular velocity (which is relatively small) about an axis drawn from the grip to the CG of the club head where the net (integral ... sum total) of the centripetal acceleration is acting. Velocity is proportional to angular velocity and distance from the axis of rotation. Because the toe and hossel are farthest from this axis they move the fastest/ Because the "sweet spot" is close to this axis it moves very slow."

I disagree strongly with your depiction of events. During the release swivel phase and HH action phase of the swing, the different club parts are not rotating about the imaginary axis between the grip and the CG of the clubhead. What is happening is that the imaginary axis is moving in space due to movement of the flat left wrist/hand in space. The movement of the flat left wrist/hand occurs along a circular arc (relative to an imaginary center of the circle situated "somewhere" within space and all those parts (toe of the club, sweetspot of the club, hosel of the club) have the same angular velocity as the rotating flat left wrist/hand relative to the center of the imaginary circle. In other words, any point on that imaginary axis between the grip and the CG of the clubhead has the same angular velocity as the hosel and toe of the club - with respect to the instantaneous center of the imaginary circle of the flat left wrist/hand's rotational arc. The key point is "instantaneous" - if the flat left wrist/hand suddenly rotates along a tighter curve, then there must instantaneously be a different imaginary circle of rotation for all the rotating units (left hand, hosel, sweetspot, toe of the clubhead) which always have the same angular velocity relative to the center of that instantaeous imaginary circle of rotation. The only time that this system will breakdown is if the left wrist suddenly bends and doesn't remain flat.

Jeff.