[12 piece bucket]

golfbulldog, I'll attempt an answer with one caveat: I'm no Homer Kelley TGM expert. My understanding of "straight line delivery path" is taking ones hands from the top straight towards the ball. My understanding of "circular delivery path" is ones hand following a circular path from the top.

Neither of those scenarios happens... ever... The only golfer that has a circular delivery path is a machine: either pingman or iron byron. Its clear from Nebit et al that the hand path of all (real) golfers is curvilinear and is unique to each person. Furthermore all hand paths have three distinct phases defined by max/min of the hand path radii and a change in the trending direction of the center of curvature. Those parameters define a golfer's unique signature or swing "fingerprint" if you will.

In the optimization phase of the subject study, Nesbit (and McGinnis) did consider a circular delivery path and (given the scratch golfer's individual constraints) it was indeed better than the scratch golfer's original (much more elliptical) hand path (that is assuming a human golfer is even physically capable of putting his/her hands on a circular delivery path) but.... (as mentioned above) Not as good as an optimized curvillinear path.

Homer Kelley would have been lucky to have had a Commadore 64 computer when he's was researching the golf stroke. Its almost unfathomable how much more commuting power Nesbit (and all of today's researchers) have access to (including software tools and speed). Perhaps one needs a technical to understand this tremendous advantage and therefore no fair comparison can be made.

That said ALL research builds apon what came before... ALL technical papers begin with a review of the previous literature. We scientists pay hommage to people like Homer who paved the way for what was to come.

One of my favorite movies is Kubrick's 2001 a Space Odyssey... Its an allegory for man's "Great Work" in the alchemical sense based on Clarke's Childhoods End. One could liken TGM as the result of the first appearance of the black monolith... Thanks to the efforts of people like Prof. Nesbit the black monolith has made its its second appearance and Golfdom is the beneficiary. The wheels of progress grind slow ... but oh so smooth!

I encourage those readers that find value in Nesbit's reseach like I do to drop him a linet. He says if we keep reading he'll keep writing. (What a deal!) Anyway I've asked him to test some pros so we can see how their dynamics compare to the amateurs.

Thanks for linking this stuff. Haven't had a chance to read . . . . BUT am VERY interested. I'm pretty sure I won't be able to comprehend all of the math stuff . . . But if you had to give a for doofus' explanation of the "optimal" hand path what would it be? Is there any "fixed point of reference" with regards to the measurements? Is it the spine or shoulders or ball or some sort of point "in space"? You mentioned that the radius is constantly changing (which makes sense) . . . but radius from the hands to what point? Also do you think the "optimum" path changes for different clubs?

Interesting stuff.