[Zin14]

Jeff,

There is really nothing that continued acceleration can contribute to ball speed over the half-millisecond impact interval.

Your reference draws heavily from Cochran & Stobbs. They also did a study where they created a club with a hinge in the shaft near the hosel so that there could be no force applied to the clubhead in the direction of travel by the shaft or anything connected to it. They found no experimentally significant difference between shots hit with a normal club and the hinged club. It's as though the clubhead is on a string at impact.

I realize that TGM teaches otherwise. But I believe that if you perceive impact in the TGM manner and execute the stroke according to that perception, you will enter impact with the best set of alignments and vectors, including high clubhead velocity.

Zin14