[ChrisNZ]

The Left Arm lies always in the Vertical Plane of the Left Wristcock -- the Plane of the Left Arm Flying Wedge. That Left Wristcock Motion may or may not be on the Angled Plane of the Stroke.

Typically, assuming a #3 Accumulator Angle and Start Up and Release Swivels, the Left Arm is On Plane from the end of Start Up until the beginning of the Release. During Start Up and Release, the Clubhead appears to move in an Arc 'around and outside the Hands' when related to the Left Arm. Where there is no #3 Angle (6-B-3-B), there is theoretically a Left Shoulder Plane, and the Left Arm is on that Plane throughout.

Interestingly, again assuming the existence of a #3 Accumulator Angle, the Right Forearm is On Plane when the Left Arm is not, that is, during Start Up and Release.

And vice versa.

Interesting is the word! Thanks Lynn. I always thought that according to the book the left arm was never on plane, and that extensor action was therefore always below plane. It really helps to have you identify the points where the left arm is on plane - it was kind of what I thought - during the roll portion of the release the left arm actually kind of rolls under and out of the way (as opposed to the right arm going out around the left arm) - right?

Even so, I still think when you say the left arm is on plane it can still only by more-or-less on plane - not exactly on plane. But I won't push it!

Chris