10-18-a & 10-18-b
 

One of the most confusing component variations for me is 10-18-A and 10-18-B.

In 10-18-A, the wrists are Turned during Startup and Rolled into Impact. The Clubshaft is not on Plane during the Backstroke.

10-18-B, has the Left Wrist Bending during startup so the Clubshaft can be on Plane during the Backstroke.

10-18-F is most widely used on Tour. Look for the Single Action Backstroke, then at the End of the Swing or at the beginning of Start down, the wrists Turn (Club head drops) and at Release they Uncock then Hinge Roll into Impact.

Or am I confused? It wouldn't be the first time. :(

Light Bulb just Turned - On. When the the wrists are Turned clockwise during the backstroke HK calls it Turn. When the Wrists are Turned during the Downstroke, HK calls it a reverse Roll.