Head-to-head

I totally agree that emulating VCS is not the ultimate goal, but it does seem like a good starting point. For instance, I think weighting similar situations by chronological rank instead of raw age is a good insight that I wouldn't have noticed if not for considering how things work in VCS.

Oh, I did try phasing out nearest point instead of oldest point for a while. I thought that was such a great idea (I recall it came out of a discussion between us), so I tried hard to tweak it into submission, but I never got any improved performance out of it.