[Yoda]

The golf club is an implement that has a weight on the end of a stick (shaft). The weight on the end of the stick is heavier than the stick. Whenever such an implement is thrown "end over end", the lighter shaft must revolve around the heavier weight on the end -- i.e., the heavier weight on the end becomes the center or axis of rotation. A hatchet is an example.

This is exactly right, Bob. And the phenomenon produces a very interesting visual effect.

The thrown hatchet's center of mass (or its proxy, the center of gravity) is moving a smooth arc on its way to the ground. In fact, it is attempting to move in a straight line, but gravity is pulling it toward the ground. Despite the unwavering parabolic arc of the center of mass, the rotation of the handle around that center of mass produces a visual 'tumbling' or 'wobbling' effect. That appearance of 'wobble' is caused by the hatchet's non-uniform distribution of mass, i.e., more mass is located in the head than in the handle. A thrown baseball or Chinese throwing star http://throwing-star.gungfu.com/ does not appear to wobble because, unlike the hatchet, its center of mass is directly in the middle. The point is that an object always rotates about its center of mass, despite any appearance to the contrary.

Similarly, during the Golf Stroke, the Clubshaft rotates about the Center of Mass (the Sweet Spot) of the entire Golf Club. As it does so, it moves from its own Plane -- the Clubshaft Plane at Impact Fix and Address -- to and from the Plane of the Sweet Spot.