Rick, thank you for explaining what you and Randy use and how you think about it (and thank you to Mary for bringing the topic to your attention).

I am having trouble with this line of reasoning. A stall, the premature separation of flow, creates lots of drag. This drag is lost power generated in the high-lift section of the sail when you look at the sum of forces.
When we stall our mainsail due to oversheeting, we can feel the boat wanting to heel over (due to the extra sideways force created by separation), but it dont want to go forward very fast. Sailing with the mainsail on the brink of stalling on the other hand, is fast in my experience. This is the trim we are looking for and are achieving when the leech telltales flick forward now and then (sail is then having early separation in the leech area some of the time, but reestablish quickly). This is especially so sub-trapeze conditions, in more wind we find it hard to oversheet the main as the wind has enough energy to follow the surface almost no matter what we do.
Who is up for some two-boat testing <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />