[12 piece bucket]

Not exactly. Dig deeper. Really deep..............

The downswing travels from the Top or End to the Release. The downswing is the "hand acceleration phase" of the swing. The speed that the hands are moving (MPH) at the end of the downswing, is the fastest that they will be moving throughout the swing (I know, it's depressing). We cannot possibly move the left arm with muscle power (in this phase) as fast as we can with Pivot Power. However:

“Left Arm Power” in any form or amount can still be considered #4 Accumulator Action. Otherwise it actually substitutes for the Pivot to introduce the circular motion required to produce Centrifugal Force."

That's ok for shorter strokes but what about when I really want to smash it? Then:

6-B-4-0 As Accumulator #4 it is Pivot (Body) Power supplying the initial acceleration of the Downstroke to throw the Lever Assemblies toward Impact by the Thrust of the Shoulder Turn.

So, if we maintain an inert left arm and allow the Pivot (remember that the Shoulders are part of the Pivot) to move the left arm, we will achieve our 300 yard drives (if you are young, strong, flexible, and try really really hard for a long time, and it wouldn't hurt to see Ted and Yoda a few times).

Did you catch that? Did you hear the quiet roar? “throw the Lever Assemblies toward Impact”… Which are? The left arm and Clubshaft.

But wait, there's more. The right shoulder moves down and out, On Plane (resulting in the left shoulder moving also on plane). Ya see, you don't really try to move the left shoulder either. So, the right shoulder moves the left arm and Clubshaft toward impact. It's kinda like FedX sending a package to Nevada from Chicago, Via New York.

"To clear the fog, consider Pivot Thrust as Body Power blasting the Swinger’s essentially inert Left Arm into orbit toward Impact."

Gosh, How fast will the left arm be traveling when it "Blasts" off toward impact?
Not any faster than it was going before it released away from the chest. (kinda makes you want to know more, doesn't it?)

It’s actually a lot more complicated that that. But what a great ride! Ya gotta love this stuff.

DISCLAIMER
(All of the above may or may not be entirely correct. It may need correcting by a Golfing Machine expert. It’s really hard to put it simply. But hey, it was fun to write. )

Damn good post.