[YodasLuke]

If one is using a three accumulator stroke while hitting does the right arm start its thrust from the top since the right shoulder is providing motion and not action? I assume that when using a four accumulator stroke the right shoulder thrusts downplane as a first stage rocket, and after the shoulder picks up the momentum then the right arm can straighten down the angle of approach?

I was listening to an audio of Homer today. He said the right arm can start straight from the top.
In four barrel hitting, the right shoulder does begin the startdown. Once any slack is removed and the momentum toward the ball has begun, the right shoulder still becomes a platform from which the right arm is thrusting. The maximum speed of the right shoulder is achieved very quickly and loads the #4 pressure point, but only for a fraction of a second. The right arm can begin thrusting at any pre-selected point in the downstroke to begin the simultaneous release of #1, #2, and #3.