[Bigwill]

It depends on what you relate the ball to. In relation to his left heel, the ball is in roughly the same spot. However, the left heel, due to the narrowing of the stance, is in a different place relative to the left shoulder. If you use the upper body as a point of reference, while narrowing the stance for progressively shorter clubs, then is there really a constant ball position at all when placing the ball off the left heel for all shots? From this perspective, it seems like the "constant position" and "moving position" camps are doing basically the same thing. They're just taking two different roads to get there.