left shoulder?
 

When and how does the left shoulder slow down during the forward swing?

Only when the Component preceding it slows down.

On the forward swing if I try and hold the left shoulder at impact position I get a better hit. Seems like if I don't try and hold the shoulder it spins left to early. Does this tell me something about my swing ? Could I be lacking a full shoulder turn?

You may not be getting enough hip slide or doing it at the right time. Remember the bump that is needed, hula hula. Once the hip slide occurs, you the left shoulder goes up as the right shoulder goes down and forward on plane. If your right shoulder drives on plane, your left shoulder will move correctly.

shoulder
 

Ben Doyle had me stand behind him and put two hands on his scapula. The shoulder motion is constant. What ever the feeling is in an illusion. Now the hips are another matter.

When the Right Shoulder slows down , the Left will do likewise. They are connected after all, but it is only the Right Shoulder that is Aligned in some manner.....to the Plane Line.

If one uses an On Plane (Right) Shoulder Throw the Left Shoulder will respond accordingly.

If the right shoulder moves down plane then the left shoulder must move up so the shoulders do not always go back and through? They must at some time just move down and up?

Good point Jerry.

If the Head is Stationary, then the Shoulders move around it. It may not be so much a question of how fast they move, but rather how Far they move.

To sustain the Lag, all of the Pivot components must keep moving at least through the Impact Interval. No quitting.

Yes , if I understand you correctly.

Though one might think their Shoulders turn on the same plane going back and through .........given any Hip Slide , which will Tilt the Axis of the Shoulders ......... and thereby lower the Right Shoulder (all the while with a steady head)..........the plane of the shoulder turn on the Downswing will become Steeper.

The guys who subscribe to Rotated back and through, given any Hip Slide dont actually achieve a non shifting shoulder turn plane.

I been experimenting with using the hips more for balance and stability, less as a primary activator of the swing. The less conscious I am of the weight shift and just"allow it to happen" the better quailty of my ball striking.

The shoulder seem to be a different matter though, I been more conscious of my scapula as a power source to assist ball and socket motion of the humerus. Why would Ben want the scapula to remain still? I think scapular retraction and protraction is important part of the shoulder motion.