[Yoda]

Forgeting anatomy for a second, what is efficient circular motion? A rock on
a string - a stable hub and a constant radius, agreed?.

If you make a left arm only swing (zero body/shoulder motion), yes, you would
have a 'hub' at the left shoulder.

If you make a right arm only swing (zero body/shoulder motion), yes you would
have a 'hub' at the right shoulder.


And if you have both hands on the club and pivot around the spine, that
'total motion' hub of the hands, the tip, can not be either the left
shoulder, nor the right. It may 'seem' to be the left shoulder, because yes,
that IS a point of rotation of the left arm, and it may appear that the right
isn't a component, because the right side of the triangle isn't straight
until past impact (hence the swing 'feels' much more left sided).

In a sound Golf Stroke, the Left Arm swings in an arc around its Center at
the Left Shoulder. In Pivot Strokes, this Stroke Center is in motion around the Pivot Center. The fact that
the Left Shoulder is 'in motion' (and thus produces less than a 'perfect' circle)
does not negate the fact that it is the true geometric center of the
circumerence Traced by the circling Clubhead. Further, the Right Arm never
swings from the Right Shoulder, even in a Right Arm Swing (in which case the Stroke Center is transferred from
the Left Shoulder to the Right Elbow).


Thus, there is ideally only one 'circle' in the Stroke and that is the one
whose circumference is Traced by the Left Arm and Clubshaft Radius.
Attempting to introduce a Right Arm Circle of any kind (in addition to the Left Arm Circle) is
totally unnecessary and, in fact, produces conflicting alignments. Active
or Passive, unless the Right Arm has a Straight Line Piston Motion, you do
not have a sound Stroke.