O.k.,This was the original post.Try this. Take a book or a folded piece of paper, place the bottom edge on a straight line, spine (or fold)to the right,tilt the top edge back towards you so that the base stays on the straight line but the top leans back ,say 3 inches, open the cover away from you 2 inches.The cover is your left shoulder at "the top".The the rest of the book is the inclined plane(left shoulder is above plane .What do we have? There is a common denominator -BOTH THE LEFT SHOULDER PLANE AND THE INCLINED PLANE MEET AT THE SPINE OF THE BOOK OR THE FOLD IN THE PAPER-WHERE THE HANDS ARE ATTACHED TO THE CLUB!:question:

Hello Neil,

I'm not able to stay away any longer. Weak.

I agree with your post above.

The 7th Edition clears this up a bit.

4-D-1. The Flat Left Wrist This section is included to stress the importance of the Flat Left Wrist during Impact. (Study 2-P and 10-18-B.) This is a highly dependable visual check for compliance with the Law of the Flail (2-K). But remember there is normally a point where Backstroke Shoulder and Wrist Motions make it difficult or even impossible to keep the Flat Left Wrist vertical to its Plane or the Right Forearm on its Plane without producing a non-golfing and Off Plane Clubshaft position or motion which is intolerable per 2-F and 3-F-6 for thinking players (1-G). (Carefully study 3-F-7.)

This was a major point of mine. The flat left wrist produces an off plane clubshaft position intolerable to 2-F. However, and this is huge; my impact is better when I keep my left wrist perfectly flat (per 6-B-3-0-1) and allow the club to "go off plane" (2-F).