I think that BM and BR are performing the same pelvic rotational movement from a biomechanical perspective, except that BM is deliberately allowing his head and upper torso to rotate as far as possible to the right (head is outside his inner right foot) to exaggerate the drill effect and to get that clubshaft perpendicular to the ball-target line. By contrast, BR is probably attempting to keep his head more stationary and within the boundaries of his stance.
Jeff.
Jeff, I don't think we see reality differently, I just don't have an understanding of bio-mechanics as you do. I do appreciate all the time you put in studying the swing and enjoy you sharing what you learn.
Thanks,
Kevin
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I could be wrong. I have been before, and will be again.