Unless you can keep the wind strength constant, and from the same direction for the duration of this time trial event, how would it be a 'fair' rating? And what purpose would your rating have once obtained?

I understand Matt's example and I've always liked the way they start the Mug Race, slow boats first, faster boats start last and have to pass everyone to win, but again, if the wind is not -contstant- all day long, and it rarely is, it's really not fair to the boats who start (or finish) in the light wind vs. boats sailing in the better wind.

I did't really like racing PHRF in mono's, where you have to wait around after the finish to see if you "saved your time" over a slower boat, same for Portsmouth racing in cats, but it beats no racing at all I guess.