It all seems to go to draw and perfection pretty fast at this level
It looks scary, but that's self-play. There is also the remote possibility that I prune too much with increasing depth, making "late plies" weaker and weaker. I only test using fast games.
There is one aspect in Bert's experiments that is worrying me, however: the better the eval, the worse the diminishing returns. This seems to suggest that if we improve evaluation, search won't matter anymore.
Maybe it is time for everyone to switch to breakthrough-draughts
Surely there is room for competition there.
Exactly! Who needs kings anyway?
Better hurry before Bert solves it on his computing monster, though.
Speaking of breakthrough. I've just computed an evaluation for this variant, and it's better than the generic one. Presumably it focuses on emulating a breakthrough table. I have no idea whether midgame strategy is actually different; I hope not.
I was comparing two evaluations, and did this with two different time controls: game in 1s and game in 4s. Both tests gave the same result. So this reinforces your theory that wilo remains constant with increasing depth/time. Furthermore, without draws, wilo = Elo so the unit is meaningful (and hopefully additive).
I also expect Killer draughts to stay interesting for a few years, but there's little doubt that it's going to follow the same fate eventually ... In both variants, I feel that there is a better balance between search and evaluation. In that context, working on search still makes sense.