[golf2much]

So to clarify then, Jen's plane is simply a plane that is 90 degrees (verticle) to the plane of the left wrist cock, through (around) the left arm as the 'hinge pin'.

Which then provides a reference point for the amount of rotation of the left arm flying wedge as it 'turns and rolls' relative to 'the' plane.

Yes, almost. If you remember the discussion about parallel lines representing the plane edge of Jen's plane as it intersects the plane of the left wrist hinge pin, because they always remain in the same plane, and by using geometry/trig, you can calculate the actual angle of the wrist cock in its actual plane. Jen's plane will always represent the degree of roll of the left forearm. It's intersection (actually the change in position wrt the #3acc plane) with the #3acc plane will represent the degree of wrist cock/release. This will be slightly different than a measure of the shaft angle to the left wrist because the left wrist hinge pin moves slightly below plane as you approach impact. The diffrence will be small, but a difference nonetheless.

G2M