[Yoda]

See 7-12 . . . I think that should clear up any interpretation issues. The title of the section is Swing Center TRIPOD. The head does't move, but what is UNDERNEATH it may. And in 1-L #1 it says STATIONARY Post (player's head). The post is IMAGINARY . . . It ain't the spine. It is a line drawn up between the feets and up through the mellon.

The term Swing Center Tripod is found only in the title of 7-12 (the Pivot Component) of the 7th edition. Unfortunately, there is no expanation or reference to this important concept in 7-12. Thus, there is an unfortunate 'disconnect' here, in that the explanation of the SCT can be found only in 2-H (also only in the 7th edition):

The important thing is that the true Swing Center for ALL COMPONENTS is around a Hinge Pin with one end at the top of the Stationary Head and the other in the ground, precisely between the Feet, with no regard for Body Location or Position at any time.