[Yoda]

Wow! The path of those balls in the photo is very curved so the clubhead will be covering those, but the sweet spot will be pointed at the plane line.

Boy that is sure something!

Right you are, Nathan. In the photo, note that the Sweetspot -- not the Clubshaft -- is pointed directly at the Plane Line (as indicated by the dowel). Yet, if I dropped the Club, it would fall directly on top of the second ball in the Arc. So, the Sweetspot is pointing at the Plane Line, but is clearly inside it. In other words...

It is On Plane.

And that Plane is the Plane of the orbiting Sweetspot, not the Clubshaft. The Clubshaft begins its journey pointing at its unique Baseline, the Baseline of the Clubshaft Plane, i.e., the Clubshaft's original Angle of Inclination. Then, assuming other than the shortest Strokes, it leaves that Plane in the Backstroke and moves to the Sweetspot Plane (which has its own unique Baseline -- usually the Target Line). During Release, the Clubshaft returns to its own Plane and remains there through Impact. Finally, from Follow-Through to Finish, it moves once again to the Sweetspot Plane. The important thing to realize is that the Clubshaft rotates about the Sweetspot, not vice versa. Said another way, the Sweetspot is always 'On Plane'...the Clubshaft is not.

Also, the curved Arc of Approach -- as represented by the golf balls -- is seen by the golfer as being on the ground. However, this is an illusion because it is actually occurring on the face of the Plane (as the clubhead orbits Down Plane through Low Point and Up Plane thereafter). The curved Path as seen on the Plane itself is known as the Arc of Attack. Thus, the Attack Arc is three-dimensional (Downward, Outward and Forward) whereas the Approach Arc is only two-dimensional (Outward and Forward).

Once these facts are understood, the illusions can be utilized for a lifetime of better golf.