[Yoda]

When Ben says "Half Roll" he is referring to the MECHANICS of Angled Hinge Action (Simultaneous Roll and Layback of the Clubface / Half Roll).

When he says "Reverse Roll", he is referring to the FEEL of Vertical Hinge Action (Left Wrist remaining vertical to the Vertical Plane (Wall) of the Stroke) and producing a Layback Only of the Clubface (No Roll or Square).

Obviously, there is a confusion here. The Three Mechanics of Clubface Motion (Full Roll; Half Roll; and No Roll) have their kinesthetic counterparts in their Three Feels (Roll; No Roll; and Reverse Roll). The misidentification of Mechanics and Feels have abided now in popular TGM literature (and commercial products) for the past 25 years, and it is high time it was cleared up. Once and for all:

Horizontal Hinge Action -- Full Roll of the Clubface -- Roll Feel.

Angled Hinge Action -- Half Roll of the Clubface -- No Roll Feel.

Vertical Hinge Action -- No Roll of the Clubface -- Reverse Roll Feel.

And there you have it.

I feel better now!