[golfbulldog]

...
It is "the Swinger's primary concern" (2-K-0).

With just your left arm and club -- and with a bit of additional pressure in the last three fingers of the left hand -- Swing back and through and back and through and back and through. Again, imitate the photos exactly.

Let your Pivot help you. This is important. The left arm has little power other than that which the pivot gives it. Contrast Sergio's belt line in Photo #10 with Photo #14. The Body Rotor turns a full quarter-of-the-way around from Release to Finish Swivel.

Point the butt-end of the Shaft at the Line (first in the Backstroke and then into the Finish). Stick a tee in the butt-end of the grip as a reminder.

Do it.

Learn Plane.

Then, with Body Power supplying the initial Thrust (in the Start Down and Downstroke), let the Club rip past the Left Arm (and your Rolling Flat Left Wrist) through Impact into the Follow-Through and Finish.

Learn Power.

Once the release has occured...is the pivot motion mainly concerned with maintaining on plane relationships/alignments? As opposed to powering the post release clubhead motion...