[Yoda]

Thus far, no one will even agree that BC's head is moving back and down from the Top to Follow-through. Can we get a yes or no on this?

I thought a head pivot center sequence would look like Diane in Chapter Nine [6th Edition]as seen in photos 9-2-1#1 (Preliminary Address), 9-2-2 #1 (Impact Fix), 9-2-10 #1 (Impact) and 9-2-11 #1 (Follow-through). She doesn't look like BC to me.

If Casper's sequence from the Top on pages 144-145 is, in actual fact, a head pivot center sequence, then I obviously don't know what a HPC is or what it's supposed to look like.

Just looking for some understanding here.

First of all, Bob, I appreciate your earlier observation that the Pivot is a two-way street. As such, the Pivot Center concept demands a constant Center in both directions. To the extent this does not occur, a compensation has been introduced. In my opinion, this is the case in the Casper Long-Iron sequence.

The many prior posts on this thread and on similar threads here and on Brian Manzella's site have focused on the Backstroke Pivot and its Center. Accordingly, the primary purpose of my publication of the Casper sequences was to provide an example of a Head Centered Backstroke. Hence, my directive in the introducing post to "Check out his Head Positon at the Top of each sequence." There is no question in my mind that, at least in these sequences, Billy is using such a Head Pivot Center. The intriguing question you have essentially introduced, then, is...

Does he change that Head Center to a Between-the-Shoulders Center on the Downstroke? Or, has he simply failed to achieve the perfection of the original Head Center?

I've already commented on the Bobbing in the Stroke. It is a common phenomenon often caused by a failure to position the Head at Address in its Impact Location (hence requiring the Bob as compensation). Regarding the backwards Sway, using that tilted, upside-down triangular shape in the background as the constant, I truly don't see the "ton" of movement you do. It is there, but photos are an exacting measure, and even the most talented among us are entitled to at least some margin of error. Homer Kelley knew that, of course, and that is why he always advised to set your Head where you want it at Impact and then do your best to maintain that location. In other words, centered between the feet (his ideal) or to the right or to the left -- wherever you put it -- leave it there, as nearly as you are humanly able to do so.

Personally, I think Billy is losing his original Head Pivot Center somewhat during the Downstroke. But, he is not reverting to a Between-the-Shoulders Center. The reason this is happening is first, the Bobbing phenomenon explained above, and second, the need for additional Axis Tilt in order to add Loft to the Hooded Clubface introduced by, in conventional terms, his extremely "strong" Grip (Left Hand Turned to Plane). If he didn't create this "artificial" Loft via the slight backward Sway, he couldn't get the Ball airborne with the lower-numbered Clubs. Essentially, he creates a new Head Center slightly down and to the right of the original Center, and he does so dynamically during the Downstroke. Given his original Address position and Grip, is is a necessary compensation.

Finally, I would like to add Photo 9-2-6 (the Top) to your list above. This photo clearly illustrates Homer Kelley's concept of a Head that Pivots on its base, yet remains Centered and Stationary (with regards to Location, not its necessary Pivot capability). This 'look' can be interpreted to mean a Between-the-Shoulders Center, but it is not. As I indicated in Post #26 above, the Ben Hogan sequence more closely approximates these ideals and, hence, Golfing perfection.