[Yoda]

my first post here...lots of good info mikeo...does this all mean the the left wrist and hand from impact to followthru, remains vertical to the plane?

Well, hello there, Olindutra, and thanks for this "first post."

The Flat Left Wrist and its Roll (Hinge Action) controls the Clubface Alignment (and the Rhythm of the Stroke) during Impact and Follow-Through. In so doing, it remains Vertical to one of the three Basic Planes of motion, i.e., Horizontal, Angled or Vertical. It remains Vertical to the Inclined Plane only during Angled Hinge Action.

P.S. Hope you're having a nice time in Panama City, Brian.