Huh? You play it on the board and let Stockfish see it so it writes it to the Hash and you can go back to some previous position with this information on the hash so Stockfish shows a different continuation?mroh wrote:What do you do if the refutation of a line is a move of the opposite side? (which sounds pretty natural to me)
Refutations of lines come from both sides and what the user does is no different, what matters is the engine sees its plan doesn't work (from either side) so it can suggest a different path.
Anyway, the hash is unreliable, it'll be overwritten, it's better to just feed everything to an engine with Persistent Analysis to store all the searches or relying on a GUI to store a tree with all relevant positions backsolved.
What a default Contempt that is not zero has shown is that Stockfish had actually become two different engines. One plays great the white side but lousy the black side (say, what'd you get with negative Contempt), the other plays great the black side but lousy the white side.
Contempt = 0 of CFish looks like a compromise, the middle ground.
It's clear to me that for analysis you want the one that plays greatly the side you're analyzing. But there's two different Stockfishes, so it doesn't make sense to pollute the analysis of the great white player with the one from the lousy one (Stockfish plays bad the white side when analyzing the black side), so while it might be impractical to use two instances of Stockfish, one for each side, it seems it's the best way to get these great moves that Contempt=0 misses.
