what am i prepared to roll on the plane line

[Yoda]

what is it that i should be rolling on the plane line ?

is it my flat turned left wrist & hand ? this makes sense as left hand is clubface control

The reference is to the Roll of the Flat Left Wrist (Hinge Action) as the Right Forearm and #3 Pressure Point Trace the Straight Plane Line.

This On Line Motion is not a true rotation (Swivel Action). Instead, the Flat Left Wrist only appears to Roll as it remains Vertical to either the Horizontal or Angled Planes. In the case of Vertical Hinge Action, the Left Wrist remains Vertical to a Vertical Plane and does not even appear to Roll.