[KevCarter]

Strictly my opinion...

D-Plane is a fairly complex examination of the "new" ball flight laws that say the ball starts approx. 85% due to the face direction at separation. For years we were taught that the path was responsible for starting direction. To really take advantage of D-Plane you need to be on a TrackMan to test several variables.

As followers of Homer Kelley, we have it easy and really don't need to change our thinking. Homer Kelley tells us in Chapter 2 -D-0:

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

We know the ball curves because of a variance in face angle to path.

Thats all I need to know to teach and play G.O.L.F. !

Kevin