[Jeff]

chbkk

From my perspective, the biomechanical movements of the torso/arms will be exactly the same if the clubhead has a width of 4", 8", 12" or 18" (presuming an identical club lie angle) because the essential need is to get the sole of the club parallel to the ground, and just touching the surface of the ground, at impact. In fact, if AK was swinging a dowel stick of the same length as his driver's clubshaft, but without a clubhead, his swing pattern (biomechanical movements) would likely remain the same as when he swings his regular driver. In all these cases, the hosel (and peripheral end of the dowel stick) would get to the same point at ground level. However, the distance of the hosel at its impact position from the ball-target line would depend on the width of the clubhead ( 50% of 4", 8", 12" or 18").

Regarding the COM (center-of-mass) question, it depends on the weight of the clubhead versus the clubshaft. Swinging an 18" wide clubhead may not be as easy or as fluid or as efficient or as biomechanically comfortable as swinging a 4" wide clubhead, but the clubshaft at impact must be on plane C, and a golfer must perform the standard biomechanical movements that AK performs to get it there - irrespective of the practical difficulties involved with dealing with the COM problem.

In that AK blue-lines example, one can draw a line between PP#3 and the sweetspot (which is 9" from the hosel). At impact, that sweetspot plane is much shallower than his clubshaft plane (plane C) at impact. If the club was swung post-impact onto that same sweetspot plane by the 4th parallel position, then AK would have to suddenly shallow his clubshaft plane post-impact while the clubshaft was traveling from impact to the 4th parallel (in order to rotate the clubshaft's hosel to the sweetspot plane). Can you imagine the "strange" biomechanical movements that would be necessary to achieve that goal?

Jeff.