27 Sep '10 22:36>
I just ran across this Nezhmetdinov game where he sacrifices his queen for two minor pieces. (12.QxBf6) Apparently, it's one of those intuitive sacs where all the variations can't be figured out over the board. Nezh even claimed that he wasn't able to calculate everything out in post-game analysis. But Nezh plays it anyway and wins the game. (The strategic basis for the sacrifice is Black's backward development and the weakness of the black squares around his king.)
So I plugged the position into a few engines, including Pro Deo 1.6 Tal, to see what would happen. Of course, Rybka and Stockfish prefer the mundane 12.Qh6, but Pro Deo Tal plays the sac! (I should point out that Pro Deo Tal isn't very strong, maybe 2000 or so. One might be able to tweak the personality settings and get the strength up to around 2500, but even then it's not going to tear up other engines. But I think it would give any normal person a good game. Also note that the evaluations for the Tal setting are way optimistic, so this can't be used for analysis - Only for fun! )
Rybka 2.3.2 best move: 12.Qh6 - eval +0.11
sac eval: -0.86
Stockfish 1.7.1 best move: 12.Qh6 - eval +0.28
sac eval: -1.53
Pro Deo 1.6 (normal) best move: 12.Qh6 - eval +0.33
sac eval: -0.76
Pro Deo 1.6 (Tal) best move: 12.QxBf6! - eval +1.13
So I plugged the position into a few engines, including Pro Deo 1.6 Tal, to see what would happen. Of course, Rybka and Stockfish prefer the mundane 12.Qh6, but Pro Deo Tal plays the sac! (I should point out that Pro Deo Tal isn't very strong, maybe 2000 or so. One might be able to tweak the personality settings and get the strength up to around 2500, but even then it's not going to tear up other engines. But I think it would give any normal person a good game. Also note that the evaluations for the Tal setting are way optimistic, so this can't be used for analysis - Only for fun! )
Rybka 2.3.2 best move: 12.Qh6 - eval +0.11
sac eval: -0.86
Stockfish 1.7.1 best move: 12.Qh6 - eval +0.28
sac eval: -1.53
Pro Deo 1.6 (normal) best move: 12.Qh6 - eval +0.33
sac eval: -0.76
Pro Deo 1.6 (Tal) best move: 12.QxBf6! - eval +1.13