[EdZ]

And let us not forget... 1-L

1-L #11

Clubhead Force and Motion is On Plane at right angles to the Longitudinal Center of Gravity (the direction of the motion) and varies with the Speed, Mass and Swing Radius

and

1-L #5

The Clubshaft lies full length on a flat, tilted plane

and

1-L #15

The Club starts up-and-in after "Low Point" but the thrust continues Down Plane during the Follow-Through

Notice that in #11 he is talking about 'the' plane and in #5 he is talking about 'a' plane.

This is a very important difference that really confuses a lot of folks regarding plane.

Add to this...

4-D-1

...It is the hands AND clubhead - not just the clubhead - that define the Plane.