[Jeff]

AC

Thanks for your input. Due to your input (including a personal communication), I think that I now understand the difference between a four barrel and a triple barrel hitter's action. I will describe the difference in my personal words and you, and others, can correct me if I am wrong.

In a triple barrel hitter's action the right shoulder moves closer to the ball before PA#1 releases, but not due to an active thrust of the right shoulder downplane. It occurs because the lower body shifts-rotates towards the ball and the sliding of the pelvis causes the entire torso (including the right shoulder) to move towards the ball. In that sense, the movement of the right shoulder towards the ball is passive, and the left arm moves to the same degree as the right shoulder so there is no increased pressure at PP#4.

In a four barrel hitter's action, an independent right shoulder thrust occurs at the start of the downswing that is independent (and supplementary) of the passive movement of the right shoulder that occurs secondary to the hip slide movement that occurs simultaneously. That independent/active right shoulder thrust movement increases pressure at PP#4 and thereby activates the release of PA#4. Shortly thereafter, PA#1 releases and drives the release of PA#2 and PA#3. Therefore, the total action is a four barrel action.

Jeff.