Author: Roy Brunjes
Date: 23:44:33 07/19/04
Earlier I posted about this position with the question "Is the exchange sacrifice 13. ... Rxf4!? sound?" [D] r1b3k1/pp2n1b1/1qn1prpp/2pp4/5B1P/2PP1NP1/PPQ2PB1/RN3RK1 b - - 0 13 Some readers thought it should be, others were not so convinced they would play it themselves in a game (not necessarily a vote for or against the soundness, just that they might not play that move themselves in a game). I'm a weak player myself, so I thought I would have the programs play it out to see how things went when pitting various engines against Chessmaster. I started the games shown below after Black's 14th move. The assumption here is that White cannot afford to decline the sacrifice as he would be a piece down. Below are the first 14 moves as originally played between Shredder 8 on a 2.8 GHz Pentium IV and Chessmaster 9000 (Personality=SKR_JR_MIX which is my own creation that is derived from the SKR personality developed by Kurt and others) which ran when this game was originally played on my Centrino 1.5 GHz laptop. Today, to make things more interesting and to try to lend more weight to the argument that 13. ... Rxf4 is indeed a very strong move, I ran Chessmaster on my old Athlon 700 MHz machine while the other ChessBase engines (tried out one after the other against Chessmaster on the 700 MHz Athlon) ran on my quite fast Centrino 1.5 GHz laptop. Earlier tests I ran showed that my laptop is between 3 and 4 times faster than the 700 MHz Athlon; thus the ChessBase engines had a significant hardware advantage. If Chessmaster could achieve winning positions aginst these engines while Chessmaster had a big hardware disadvantage, I think it would lend more credibility to the argument that 13. ... Rxf4 is indeed a very strong move (perhaps best?!) The first 14 moves from the original game played between Shredder 8 and CM9000: 1.e4 e6 2.Qe2 c5 3.g3 Nc6 4.c3 g6 5.Bg2 Bg7 6.Nf3 Nge7 7.0-0 d5 8.d3 0-0 9.e5 h6 10.h4 Qb6 11.Bf4 f6 12.exf6 Rxf6 13.Qc2 Rxf4 14.gxf4 Bd7 Now I started Shredder 8 up on my machine (a Centrino 1.5 GHz and slightly faster than what Shredder 8 ran on during this ICC game the other day). Here is how that game went: 15.Na3 Rf8 16.Qd2 Qc7 17.h5 Rxf4 18.Rfe1 g5 19.Nb5 Qb8 20.Qe2 Nf5 21.Rac1 g4 22.Nd2 g3 23.fxg3 Nxg3 24.Qe3 Nf5 25.Qe2 a6 26.Na3 Ncd4 27.Qd1 c4 28.Naxc4 Qa7 29.Ne3 Nxe3 30.Rxe3 Nf5 31.Qe2 Qxe3+ 32.Qxe3 Nxe3 33.Bf3 Nf5 34.d4 Nh4 35.Be2 e5 36.dxe5 Bxe5 37.Rf1 Rxf1+ 38.Kxf1 d4 39.cxd4 Bxd4 40.b3 Kf8 41.Nf3 Nxf3 42.Bxf3 b6 43.Ke2 Ke7 44.Kd3 Bf6 45.Be2 Bb5+ 46.Ke3 Bxe2 47.Kxe2 Ke6 48.Kf2 Kf5 49.Kf3 Kg5 50.Kf2 Kxh5 0-1 Hmm... Shredder 8 is no slouch as CCC readers and others well know. Next I tried Hiarcs 8 to see if its positional knowledge might help it avoid problems in this position (again, starting after Black's 14th move). Here are the moves of that game: 15.Na3 Rf8 16.Qd2 Qc7 17.Nb5 Qb8 18.Qe3 Rxf4 19.Bh3 Nf5 20.Bxf5 Rxf5 21.Rae1 a6 22.Na3 d4 23.cxd4 cxd4 24.Qe4 Rf4 25.Qe2 Qf8 26.Nh2 e5 27.Rd1 Rxh4 28.f3 Be6 29.Nc4 Qf4 30.Nd6 Bxa2 31.Nxb7 Qg5+ 32.Qg2 Qe7 33.Ra1 Bf7 34.Na5 Nb4 35.Qd2 Rh5 36.Rf2 Nd5 37.Nc6 Qh4 38.Rxa6 Qg3+ 39.Kh1 Nf4 40.b4 Bf8 41.Ra5 Rxh2+ 42.Rxh2 Qxf3+ 43.Kg1 Qxc6 44.Rxe5 Qf3 45.Re4 Bd6 46.Rxd4 Bd5 47.Rxd5 Nxd5 48.Rf2 Qg4+ 49.Kf1 Qh3+ 50.Kg1 Bg3 51.Rf3 Bh2+ 52.Kf2 Bg1+ 53.Kxg1 Qxf3 54.Qc2 Qg4+ 55.Kh2 Nxb4 56.Qb3+ Kf8 57.Qc3 Qe2+ 58.Kg1 Qd1+ 59.Kg2 Qc2+ 60.Qxc2 Nxc2 61.Kg3 Nb4 0-1 And again, Chessmaster on the much slower hardware is victorious. And now for Fritz 8.0.0.23 (same deal -- first 14 moves as before): 15.Bh3 Rf8 16.Re1 Rxf4 17.Nbd2 Nf5 18.Kg2 Qd8 19.Bxf5 Rxf5 20.Rad1 Qb8 21.Qb3 b6 22.Re3 Qf4 23.Rg1 Ne5 24.Qc2 Nxf3 25.Rxf3 Qxh4 26.Rg3 Ba4 27.b3 Bb5 28.Nf3 Qf4 29.d4 g5 30.Re1 h5 31.Ne5 Bxe5 32.Rxe5 h4 33.Rge3 Rf6 34.Kh1 Be8 35.Qe2 Bg6 36.Kg1 Bh5 37.Qf1 Bf3 38.Qh3 Be4 39.Qf1 Qg4+ 40.Kh2 Kf7 41.R5xe4 dxe4 and White is definitely in deep trouble here. I ran out of energy at this point ... So, with three very strong ChessBase engines all having much faster hardware than Chessmaster, I have to believe this strongly suggests that in fact 13. ... Rxf4 is a very strong and sound move. Of course shoot-outs like this are not definitive, but short of hiring a GM to analyze this I do not think it is easy to know for sure. I do not think any GMs read CCC, but if you are out there, go ahead and take a shot at it please!! I also believe this might make an interesting test position for engine developers... Regards, Roy
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