OK with me to agree to disagree, but here's one more question:
I'm sure you've observed some players doing more with their strokes than others - so have I. But how did you observe that it involves longer contact time?
I mean, a normal amount of contact time is only 1 or 2 thousandths of a second, and you say that a 10% increase makes a difference in the outcome. Does that mean that you can tell by observation if a tip stays on the CB for 2.2 thousandths of a second instead of 2.0 thousandths?
I'm pretty sure I can't tell by observation if the tip stays on the ball 100% longer.
My point is, sure, we observe some players doing lots more with the CB than others, but what real evidence do we have that longer contact time is the reason? I think it's because that's the impression we get when we hit the CB better - but that's not an observation.
pj
chgo
Obviously you certainly can't accurately observe the time involved during tip contact. All you can do is come up with an interpretation of what you see. Because this is just my interpretation of what is happening, I'm willing to examine hard evidence that shows otherwse.