[BerntR]

The #3 accumulator is the part of the right wrist cock that isn't released, ref accumulator #2. But it gives leverage since forearm rotation will move the clubhead a long way. The more angle you have left the more leverage you will get. And this will be maxed with a dual horizontal hinge action.

I suspect that a shift down to the elbow plane will have less accumulator #2 release and more accumulator #3 release - compared to a turned shoulder plane.