[Jeff]

Yoda

We operate in parallel mental universes.

In my mental universe, Martin Hall has to swing his clubshaft along the plane board in order to keep the sole of his 12+" wide clubhead parallel to the ground at impact. You simply choose to ignore the need for the sole of his wide clubhead club to be parallel to the ground, and roughly on ground level, at impact.

Consider this photo of Anthony Kim produced from the following swing video.

Swing video -

In this photo, A represents his clubshaft plane in the mid-downswing. B represents his clubshaft plane in the finish phase. Both A and B are on the same inclined plane as C ( C is his clubshaft plane at impact) because Anthony Kim has a perfectly symmetrical swing.

Now imagine Anthony Kim swinging a club that has a clubhead width of 18" and an identical club lie as his regular driver - represented by the blue lines. Point X is the sweetspot at impact and it is 9" from the hosel.

In my mental universe AK has to swing his club so that his clubshaft is exactly on plane C at impact - in order to get the sole of his 18' wide clubhead to be parallel to the ground at impact and just touching the surface of the ground at impact. In my mental universe, X rotates to B - in other words, the sweetspot rotates to the clubshaft plane at B (while the clubshaft simply remains on-plane between C and B).

Jeff.