[O.B.Left]

Yes. I agree. Anyone who reads 2-D-0 should understand "practically at Right angles" in the context it was stated. "Practically at Right Angles" when the Player has used Hinge Action.

I like this idea about the context in which 2-D-0 was presented. It should be noted, given the current state of affairs where people try to trash Homer in the light of new scientific evidence ( be it real or imagined) . If I may offer my personal perspective .....

2-D-0 DIRECTIONAL FACTORS
".....The direction of the ball will always be practically at right angles to the Clubface and square to the leading edge of the Clubface at separation....."

In Homer's time the PGA of America, perhaps with some help from John Jacobs (who might not have read Search for the Perfect Swing) thought the ball left the clubface in accordance with the clubheads line of flight and curved to where the face was pointing. A belief that was shared by most every golfer from the Sunday morning hacker to the PGA Tour pro....... until quite recently actually.

Homer didnt agree. Though he wasnt the first to propose that the opposite was actually true, his views on the subject were still considered to be "different". Even the tape recordings of his GSEM sessions contain some lengthy discussions on this subject.

So, its my opinion that in Homer's day 1-L 16 and 17 were somewhat controversial (ish) pronouncements. There's the context. Today, where we have an argument over whether Homer was correct vis a vis Trackman etc it should be remembered that the fight in his day had him on the compete opposite side of the geometry. A fight he won. So dont take "square to the leading edge too lightly" although its wasnt anything like the "Frankly Scarlet , I dont give a damn" of its day, golfwise it was "different". That more than Trajectory was where the controversy lay.

And now for the rest of the story..... The word "practically". You could take that to mean "almost" or you could take that to mean "for practical purposes". I believe Homer meant the latter. The book he once said was "written for the guy standing on the tee". So I believe he meant something like.. "for practical purposes", the player should align the clubface as if the ball will leave vertical to the face and square to the leading edge. Did Homer actually think that the ball responded that way literally, every time? No. Although again, I believe he thought the variance was far more pronounced in terms of Trajectory than in terms of Direction (left and right from a birds eye perspective).

2-B TRAJECTORY CONTROL:

Clubface loft (2-C-1) and Hinge Action (2-D) determine altitude and backspin and are the basic elements of Ball Control.

Also per 2-D-0 again, "deviations" in Horizontal Hinge Action during Impact can influence initial direction but only by virtue of the fact the clubface is pointed in another direction.

2-D-0

"....... Deviations in Horizontal Hinge Action during Impact can produce considerable variation in the direction but little change in trajectory. Deviations in Vertical Hinge Action during Impact can produce great variations in trajectory but little change in direction. Angled Hinge Action on the flatter Planes (10-6 , 10-7) approaches the Horizontal Hinge characteristics and as the Plane steepens it moves toward Vertical Hinge characteristics. Study 2-G"

Does this mean Homer is at odds with Trackman etc? I dont know. I dont care really. Its an argument about how correct Homer was given the theoretical fight he was in during his day. I'd be interested in seeing how Trackmans 15% is divided amongst what Homer termed Direction and Trajectory. Which one has more associated variance? I bet its Trajectory. Is that where most of the 15% lies? Anyone know?