[Jeff]

Bagger

You would have to supply a solid physics/mathematical explanation for your assertion that a skier cannot accelerate between point B and point C if he keeps his skis constantly angled for me to consider your assertion seriously. Those U-tube waterskier competitors straightened their skis after accelerating sufficiently, so that they could have a straight-line directional launch from that launching platform.

There is a big difference between a waterskier between point B and point C (and Tiger Woods' club between point B and point C in his swing). Because of the presence of waterdrag and an increasing angle between the rope and the the skier's curved path, the skier will slow down as he passes point C and approaches the boat. By contrast, in a golf swing, air-resistance doesn't impede the release phenomenon in a golf swing, and there is no reason why the club cannot continue to accelerate between point B and point C. In fact, the club does and the clubhead passes the hands after impact.

The waterskier example obviously has limited analogy to a golf swing because the left hand undergoes a 90 degree rotation during the release swivel, as you pointed out, and that is an obvious confounding variable.

My only point of using the waterskier analogy is to give an analogous, easy-to-understand, example of the principle that underlies the release phenomenon - that it is due to angular acceleration developing because the hand pull on the grip is at an angle to the club's COG-momentum and that i) variations in hand speed and ii) hand arc curvature at all time-points during the downswing will cause variations in the degree of angular acceleration during the downswing, and therefore release variations - between different golfers (as nm golfer's mathematical explanation predicts).

Another added point - I have a PingMan-type driver-testing machine at the golf facility where I practice, and I have studied that machine's release action. It has a passive hinge joint that can rotate >90 degrees to simulate the release swivel. Interestingly, it always rotates perfectly during the release even though the hinge joint is totally passive - I presume that it has something to do with the COG of the clubhead causing the clubhead to automatically rotate to a square alignment at impact. I also have noticed that the central arm's swingarc, and therefore hinge joint's (between the central arm and clubshaft) swingarc is circular, and that the central arm travels at a constant speed. There is no endless belt pulley analogy that is applicable to that machine and yet it releases the clubshaft perfectly/naturally - the only "release phenomenon" explanation that presently makes sense to me is nm golfer's mathematical explanation.

Jeff.