Homer assumed Separation to be at Low Point but what if it isnt?

[Daryl]

Those are fantastic drawings Daryl. But Im not sure about the "fade" and "draw" in the first one. I know your coming from a True Swinging perspective , but the face angles seem wrong to me. The fade looks like a push fade to me........my head hurts...

Per 1-L-17 the ball leaves at right angles to the clubface at Separation. Side spin coming from any divergence in the clubhead path to the clubface angle.

The opposite of the old ball flight rules but now confirmed by Trackman.......which casts a peculiar light on a lot of past champion's own instruction books. Homer was adamant that they couldnt have actually done what they teaching. A belief that didnt go over too well with his listeners but he insisted. And we now know he was right. To think that some of golfs greatest champions were manipulating the clubhead path and face angle perhaps subconsciously, in the direct opposite manner than that to which they subscribed theoretically makes for an interesting discussion.

Sean Foley has said that he likes his players to draw the ball with an open face angle of 3 degrees and then create the side spin with their arcs. So the ball starts right then curves back. He's probably got a Trackman on the range at OCN I'd imagine.

Well, don't get a headache over it.

The Top drawing only shows the amount of clubface Roll with three different ball locations with an On-Plane Swing.

1. The Aft Ball Location would cause a Push
2. The Forward Ball Location would cause a Pull

When Opening or Closing the Plane Line in addition to the change in Ball Location............

7-2 For the “True” Swinger, “Opening” the Plane Line (10-5-D) until it is square to the Clubface alignment at the new “Aft” location, will produce a “Fade.” With the Ball moved Forward, “Closing” the Plane Line (10-5-E) square to the Clubface alignment at the new location, will produce a “Draw.” The Curve of the their paths, after the straightaway initial direction, will be proportional to the divergence of the Plane and Target Lines. Herein, “Path” terms (Ball Path etc.) refer to total Ball behavior, whether or not it remains straightaway. “Line” terms (“Target Line” etc.) refer to the straightaway direction of Aim.

As I understand "Trackman", it's a mathematical model. Data is collect by user input and radar. The data and results are illustrated in graphical format. The amount of data collected by the radar and the amount of this data available to the user may be very different. The calculations are also proprietary. But it's accuracy, I read, is almost perfect.

Trackman sets up behind the ball and doesn't "see" the actual Clubface-Ball contact because the clubhead obscures it. I'm not a mathematician and I couldn't begin to wonder how complex or simple the calculations might be although models to determine distance have been used by clubmakers for a long time now.

I don't know if Trackman measures ball flight and then calculates clubhead/face path and geometry or the other way around or a combination of both. What if you swung the club without a ball?

If Trackman uses any ball flight data to calculate clubhead path, face angle and swing plane, I can't be a "True Believer" in it's use as a training aid because I can't accept mystery. Besides, ball flight cause and effect are Apples and Swing Mechanics are Oranges. But I imagine it would make an excellent clubfitting tool and it does make for fun TV ball flight instant replays.

2A ...Roll of the ball on the face of an inclined striker does not account for all the action produced by such an impact, especially in imparting spin to the ball. When the direction of the compressing force does not pass exactly through the center of the ball, a spin will be imparted to the ball. It will rotate on the plane of a line drawn form the line of compression to a parallel center line.

I don't have the mental faculty to even wonder how complex that calculation would be.