[O.B.Left]

5. A "chest launch" produces uncentered rotation. And is little more than a #1 pp "lite" slid up the arm.

Agreed on the head thing. Not sure what you mean by "pp #1 lite" why not just pp #4?

I don't want to get you stuck on this single point but doesn't the above "uncentered" rotation bring with it a critical acceleration multiplier? Let me explain my thinking and please tell me if my layman's logic is wrong mechanically.

I see it, the whole motion as a multiple levered system , with multiple centres therefore. Take the Downswing Sequence for instance , with its initial period of shoulder acceleration about the pivot centre (a place between the shoulders) followed by a period of (left) arm acceleration about the left shoulder . These two levers if you will are sequenced in initiation but overlap somewhat i.e. the left shoulder is still moving while the left arm is accelerating away from the chest via throw out or drive out. An uncentered motion yes but a powerful "blast off" as the left arm is now moving faster than mere pivot rotation would allow.

Also , in terms of mechanical advantage when the left arm (the upper portion of the primary lever ... the "primary lever" the thing we are really swinging or driving , our main concern in the hierarchy of levers) lies across the chest in Startdown (the period of shoulder acceleration) the radius in question is one that extends from the pivot centre. Not from the left shoulder! Making the radius effectively about a half a left arm shorter and therefore theoretically easier to turn with Pivot Power. #2 angle shortens the radius length as well of course but the portion of left arm extending from the pivot centre is shorter too!

Sort of like bicycle gears in a way. Perhaps . Maybe. Small radius to large as you pick up speed. Each with a corresponding amount of drag . We ramp up speed by metering lag and drag. Some see it as being similar to the figure skater spin deal where the hands and arms are closer to the centre of rotation.... the longer radius upon arm extension slowing the pivot rotation . Whatever, the system requires a proper timing of the sequence to work properly. No amount of brute force will overcome the disadvantage of starting in 10th gear as opposed to 1st.

As an aside , this relates to the reason why I don't personally subscribe to the "keeping the arms packed" theory for full power shots anyways. Hold off's , low shots, fades, angled hinging, hook prevention etc ...... sure I'll do that, feel the "pack".

Trying to think of a mechanical model. How bout this kids propeller toy. Imagine the blades as being the shoulders , not the arms. Now imagine another even longer straight piece representing the left arm attached to the left shoulder propeller blade by a piece of string. Upon rotation would not the far end of the left arm piece move the fastest of any component? Uncentered though it is . Incidentally having a string like connection between left arm and left shoulder is a must for power transfer. Muscle tension at that connection is a silent killer..... if you ever lose power under stressful tournament conditions , or in cold weather, check your string connection. Need a big drive ... make sure its string like.