Author: John Merlino
Date: 09:04:51 07/25/02
Go up one level in this thread
On July 25, 2002 at 00:55:34, Slater Wold wrote: >On July 24, 2002 at 23:55:58, John Merlino wrote: > >>On July 24, 2002 at 23:34:17, Slater Wold wrote: >> >>>[D]1N4br/3pkPp1/6PP/8/pp3P2/8/P4r1P/6K1 w - - 0 1' >>> >>>Every program I tested found the correct move in about 5 seconds. >>> >>>Every program I tested then failed low for 10-13 ply. >>> >>> >>>The real test here is not "finding" the move. But finding that it's winning. >>> >>>How long does it take your program to find hxg7, and _know_ it's winning? >> >>Chessmaster 9000 (PIII-600) finds the move instantly, and DOES fail low at ply >>10. After that, the eval stays steady through to ply 13. >> >>Time Depth Score Positions Moves >>0:00 1/3 3.32 1973 1.hxg7 Rhxh2 2.f8=Q+ Ke6 3.Qxg8+ >> Kd6 >>0:00 1/4 4.70 9531 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 >>0:00 1/5 4.40 16406 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Kg3 Kxg7 6.Nxd7 >>0:01 1/6 4.40 74263 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Kg3 Kxg7 6.Nxd7 >>0:01 1/7 4.39 87914 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 Kxg7 6.Kg3 >> Kg6 >>0:02 2/8 4.42 124497 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 Kxg7 6.Kg3 >> b3 >>0:02 3/9 3.80 203060 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.Nf6 >> Kxg7 7.Ne8+ Kg6 >>0:05 4/10 2.01 422430 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 >> axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 >>0:33 5/11 2.00 2574161 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 >> axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 9.Kg3 >>1:05 6/12 2.07 5089526 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 >> axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 9.Kg3 >> Ke6 >>3:04 7/13 2.03 14522913 1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 >> Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 >> axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 9.Kg3 >> Ke6 10.Nb2 >> >>HOWEVER, hxg7 still appears to lose anyway! After forcing CM9000's main line of >>1.hxg7 Rg2+ 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 (and you should agree that all >>of White's moves are forced), we get this position: >> >>[D]1N6/3p1kP1/8/8/pp3P2/8/P6K/8 w - - 0 5 >> >>And Chessmaster says this: >> >>Time Depth Score Positions Moves >>0:00 1/3 3.06 356 5.Kg3 b3 6.Nxd7 bxa2 >>0:00 1/3 4.38 392 5.Nxd7 Kxg7 6.Kg3 Kg6 >>0:00 1/4 4.41 945 5.Nxd7 Kxg7 6.Kg3 b3 >>0:00 1/5 3.77 4520 5.Nxd7 b3 6.Nf6 Kxg7 7.Ne8+ Kg6 >>0:00 2/6 2.00 11934 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 >> 8.Nc4 Kf6 >>0:00 3/7 1.99 25482 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 >> 8.Nc4 Kf6 9.Kg3 >>0:00 4/8 2.06 50786 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 >> 8.Nc4 Kf6 9.Kg3 Ke6 >>0:00 5/9 2.01 99429 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 >> 8.Nc4 Kf6 9.Kg3 Ke6 10.Nb2 >>0:02 6/10 -2.43 204435 5.Nxd7 b3 6.axb3 a3 7.b4 a2 8.b5 >> a1=Q 9.b6 Qxg7 10.Kh3 Ke6 >>0:04 7/11 -3.32 479598 5.Nxd7 b3 6.axb3 a3 7.Nf6 Kxg7 >> 8.Ne8+ Kf8 9.Nd6 a2 10.b4 a1=Q >> 11.b5 Qd4 >>0:07 8/12 -3.73 740137 5.Nxd7 b3 6.axb3 a3 7.Nf6 Kxg7 >> 8.Ne8+ Kf8 9.Nc7 a2 10.Ne6+ Ke7 >> 11.Nd4 a1=Q 12.Nc6+ Kd6 13.Ne5 >>0:13 9/13 -4.20 1263381 5.Nxd7 b3 6.axb3 a3 7.Nf6 Kxg7 >> 8.Ne8+ Kf8 9.Nf6 a2 10.Nh7+ Kg7 >> 11.Ng5 a1=Q 12.Ne6+ Kf6 13.Nc5 Qd4 >>0:24 10/14 -4.44 2318389 5.Nxd7 b3 6.axb3 a3 7.Nf6 Kxg7 >> 8.Nh5+ Kf8 9.f5 a2 10.Nf4 a1=Q >> 11.Kh3 Qc3+ 12.Kg4 Kf7 13.Ne6 Qxb3 >>0:47 11/15 -4.52 4484987 5.Nxd7 b3 6.axb3 a3 7.g8=Q+ Kxg8 >> 8.Kh3 a2 9.Kg4 a1=Q 10.Ne5 Qd1+ >> 11.Kg5 Qxb3 12.f5 Qe3+ 13.Kf6 Qh6+ >> 14.Ng6 Qg7+ 15.Ke6 Qf7+ 16.Ke5 >>1:09 12/16 -4.60 6779430 5.Nxd7 b3 6.axb3 a3 7.g8=Q+ Kxg8 >> 8.Kh3 a2 9.Kg4 a1=Q 10.Ne5 Qd1+ >> 11.Kg5 Qxb3 12.f5 Qd5 13.Ng6 Qd2+ >> 14.Kf6 Qd6+ 15.Kg5 Kg7 >> >>Is CM9000 missing something? >> >>jm > >Yes, yes, there is. It's called about 80 ply. > >Ok, here's the situation: > >When black comes down with it's rooks, which are pretty much forced moves, >*every* programs natural reaction is to take the rooks. Why? Because they are >free rooks! > >However, if you DO take both rooks, you lose. > >Here is how the game goes, all moves are forced: > >1.hxg7 Rg2+ 2.Kf1 Rf2+ 3.Ke1 Re2+ 4.Kd1 Rd2+ 5.Kc1 Rc2+ 6.Kb1 Rb2+ 7.Ka1 Rxa2+ >8.Kb1 Rb2+ 9.Kc1 Rc2+ 10.Kd1 Rd2+ 11.Ke1 Re2+ 12.Kf1 Rf2+ 13.Kg1 Rg2+ 14.Kxg2 >Rxh2+ 15.Kxh2 Bxf7 16.gxf7 Kxf7 17.Nxd7 a3 18.Nc5 a2 19.Nb3 Kxg7 20.Kg3 Kf6 >21.Kf3 Kf5 22.Na1 Ke6 23.Ke4 Kf6 24.f5 Kf7 25.Ke5 Kg7 26.Ke6 Kg8 27.Ke7 Kg7 >28.f6+ Kg6 29.f7 Kf5 30.f8Q+ Ke5 31.Qb8+ Kd4 32.Qxb4+ Ke3 33.Qb2 Kd3 34.Qf2 Kc3 >35.Kd6 Kc4 36.Kc6 Kc3 37.Kc5 Kd3 38.Kd5 Kc3 39.Qd4# 1-0 > > >So perhaps the REAL problem here is not the original position, rather this >position: > >[D]1N4br/3pkPP1/6P1/8/pp3P2/8/P5rP/6K1 w - - 0 2 > > >However, in order to solve this, you have to attain 2 things: > >1.) Taking the rook would be BAD! Most programs will see that, eventually. >However they are unable to see it in the original position. > >2.) That if you race down to the other side of the board, let the rook take the >pawn, and then race back, you will be able to stop the advancing pawns on a and >b, as well as win the pawn race on the other side of the board. > > >#1 is obtainable. > >#2 is not. > > >Most programs I have tested, if given enough time will eventually realize that >taking the rook will result in a promotion of the a or b pawns. So they go with >Kf1 however they give a stupid line that kind of goes no where. > >I thought it was an interesting position anyway. ;) That will teach me to make my program look bad! :-( If I had the test on the original position go one ply more, it would have seen that 2.Kxg2 was bad. Here are the results on the above position (after 1.hxg7 Rg2+) on a PIII-733: Time Depth Score Positions Moves 0:00 1/4 4.40 1188 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Kg3 Kxg7 6.Nxd7 0:00 1/5 4.40 2979 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Kg3 Kxg7 6.Nxd7 0:00 1/6 4.39 7499 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 Kxg7 6.Kg3 Kg6 0:00 1/7 4.42 17895 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 Kxg7 6.Kg3 b3 0:00 2/8 3.79 43104 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.Nf6 Kxg7 7.Ne8+ Kg6 0:00 3/9 2.00 78402 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 0:01 4/10 1.99 128509 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 9.Kg3 0:03 5/11 2.06 283934 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 9.Kg3 Ke6 0:06 6/12 2.02 620929 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.gxf7 Kxf7 5.Nxd7 b3 6.axb3 axb3 7.Ne5+ Kxg7 8.Nc4 Kf6 9.Kg3 Ke6 10.Nb2 0:36 7/13 -0.29 3171539 2.Kxg2 Rxh2+ 3.Kxh2 Bxf7 4.Nxd7 Bxa2 5.Nc5 Kf6 6.f5 Kxg7 7.Nxa4 Bb1 8.f6+ Kxf6 9.g7 Kxg7 10.Nb2 2:57 7/13 0.00 15699313 2.Kf1 Rf2+ 3.Kg1 I guess I have an itchy trigger finger these days.... Great position, though! jm
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