Author: Yuriy Lyapko
Date: 00:51:12 12/20/05
Go up one level in this thread
To solve such positions engine must have built-in knowledge about king blocade. I don't know about new engines but one year ago there were only 2 engines with such a knowledge(here are results on Athlon 1700+): Patzer 3.61 needs ~6 seconds to show full PV of solution: no 1 337 -551 4 Rc8 no 1 338 +321 90 Rh8+ no 2 373 +321 99 Rh8+ Kg4 no 3 390 +281 430 Rh8+ Kg4 no 3 407 -550 1081 Rh8+ Kg4 yes 3 408 -26 1329 Rb1 cxb1=Q Bxb1 yes 4 428 -28 1621 Rb1 cxb1=Q Bxb1 g4 yes 5 429 -34 3461 Rb1 Bh3+ Kg1 yes 6 446 -82 7287 Rb1 cxb1=Q yes 6 484 -457 13638 Rb1 cxb1=Q Bxb1 e3 no 6 557 -253 15252 Rh8+ Kg4 h3+ Kf4 Rf8 c1=Q Be6 Ke5 no 7 629 -253 21717 Rh8+ Kg4 h3+ Kf4 Rf8 c1=Q Be6 Ke5 Bxf5 no 8 789 -260 42230 Rh8+ Kg4 h3+ Kf4 Rf8 c1=Q Be6 Ke5 Bxf5 Qd2 no 9 1253 -257 94837 Rh8+ Kg4 Rf8 c1=Q no 10 1544 -257 133822 Rh8+ Kg4 Rf8 c1=Q h3+ Kf4 yes 10 1672 -210 148623 Rb1 yes 11 4484 -12 439543 Rb1 cxb1=Q Bxb1 e3 Bxf5 e2 f3 e1=Q Bg4 Qc3 yes 12 5249 -37 543342 Rb1 cxb1=Q Bxb1 e3 Bxf5 e2 Bg4 e1=Q h3 Qd2 Kf3 Qd3+ Kg2 yes 13 9899 -40 816985 Rb1 cxb1=Q Bxb1 e3 Bxf5 e2 Bg4 e1=R h3 yes 14 16601 -42 1256913 Rb1 cxb1=Q Bxb1 e3 Bxf5 e2 Bg4 e1=Q h3 Result: Success (1 of 1 solved so far - 100%) Found in: 1672 ms (00:00:01.672) my Bestia needs 35 seconds to switch from losing 4.f3? to 4.Bg4! no 2 0 +358 313 b8h8 h4g4 no 2 0 +158 511 b8h8 h4g4 yes 2 0 -37 851 b8b1 c2b1Q yes 3 10 -47 1697 b8b1 f5h3 g2g1 c2b1Q a2b1 h3f5 yes 4 50 -47 4371 b8b1 f5h3 g2g1 c2b1Q yes 5 50 -37 5258 b8b1 c2b1Q a2b1 h4g4 b1c2 yes 5 60 -37 8730 b8b1 c2b1Q a2b1 h4g4 b1c2 yes 6 60 -46 10647 b8b1 c2b1Q a2b1 h4g4 h2h3 g4f4 b1c2 yes 6 110 -46 24034 b8b1 c2b1Q a2b1 h4g4 h2h3 g4f4 b1c2 yes 7 230 -71 25777 b8b1 c2b1Q yes 7 460 -71 62193 b8b1 c2b1Q yes 7 460 -271 62694 b8b1 c2b1Q no 7 780 -270 100889 b8h8 no 7 870 -238 107350 b8h8 h4g4 h8f8 c2c1Q h2h3 g4f4 a2e6 f4e5 e6f5 no 7 1110 -238 146290 b8h8 h4g4 h8f8 c2c1Q h2h3 g4f4 a2e6 f4e5 e6f5 no 8 1280 -238 169856 b8h8 h4g4 h8f8 c2c1Q h2h3 g4f4 a2e6 f4e5 e6f5 c1b1 no 8 1470 -238 212836 b8h8 h4g4 h8f8 c2c1Q h2h3 g4f4 a2e6 f4e5 e6f5 c1b1 no 9 2720 -228 414942 b8h8 h4g4 h8f8 c2c1Q h2h3 g4f4 a2e6 f4e5 e6f5 c1c7 g2g3 yes 9 3110 -227 492352 b8b1 yes 9 3280 -213 521292 b8b1 yes 9 3330 -213 521292 b8b1 yes 9 3640 -39 563434 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 g2f3 e2e1Q f5g4 yes 9 4040 -39 621359 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 g2f3 e2e1Q f5g4 yes 10 4170 -64 635797 b8b1 c2b1Q yes 10 5940 -64 969853 b8b1 c2b1Q yes 10 6160 -102 1011739 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f5g4 e2e1N g2f1 h4g4 f1e1 g4f3 e1d2 g5g4 yes 10 7990 -102 1349590 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f5g4 e2e1N g2f1 h4g4 f1e1 g4f3 e1d2 g5g4 yes 11 8860 -77 1491340 b8b1 yes 11 8860 -77 1491340 b8b1 yes 11 9760 -41 1649349 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f2f3 e2e1Q f5g4 e1e2 g2g1 e2a2 yes 11 13990 -41 2481242 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f2f3 e2e1Q f5g4 e1e2 g2g1 e2a2 yes 12 15250 -41 2720604 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f2f3 e2e1Q f5g4 e1e2 g2g1 e2a2 g1h1 yes 12 30660 -41 5137399 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f2f3 e2e1Q f5g4 e1e2 g2g1 e2a2 g1h1 yes 13 34880 -46 5818892 b8b1 c2b1Q a2b1 e4e3 b1f5 e3e2 f5g4 e2e1N g2f1 h4g4 f1e1 g4h3 e1e2 h3g2 h2h3 Result: Success (1 of 1 solved so far - 100%) Found in: 3110 ms (00:00:03.110) I wonder why other engines doesn't implement this knowledge which is rather simple: 1.Stronger side has only one piece. 2.Its king has no moves. It will help in 99% cases. Here are some more examples: [D]1NK1k2N/4p3/8/8/8/4p3/8/8 w - - 1.Na6 e2 2.Nc7+ Kf8 3.Ne6+ Kg8 4.Nf7! e1=Q 5.Nfg5= [D]1N6/b7/8/7p/3p3k/5P2/6PK/8 w - - 1.Nc6 d3 2.Nxa7 d2 3.Nb5 d1=Q 4.Nc3 Qd6+ 5.Kh1 Q~ 6.Ne4= [D]5k2/1q5p/8/5N1P/6PB/7K/8/8 w - - 1.Be7+ Kg8 2.Nh6+ Kg7 3.g5! Qf3+ 4.Kh4 Qg2 5.Bd6! Qh1+ 6.Kg4 Qd1+ 7.Kh4 Qf3 8.Be7= [D]5B1k/7p/6P1/4NnP1/8/8/K4p2/8 w - - 1.g7+ Nxg7 2.Nf7+ Kg8 3.Bc5! f1=Q 4.Nh6+ Kh8 5.Bd6! ~ 6.Be5!= [D]3K4/3Rp1k1/7p/1r6/7P/6P1/2p5/8 w - - 1.Rc7! Rb8+ 2.Kxe7 Rb7 3.Rxb7 c1=Q 4.Ke6+ Kg6 5.h5+ Kxh5 6.Rg7 Qf1 7.Ke7!= [D]3kn3/4pp2/n7/5B2/3N4/b6N/4K3/8 w - - 1.Ng5 Nd6 2.Nxf7+ Nxf7 3.Ne6+ Ke8 4.Bg6! Bc1 5.Bd3! Nb8 6.Bb5+ Nd7 7.Kd1! B~ 8.Be2 Nf~ 9.Bh5+ Nf7 10.Be2 Nd~ 11.Bb5+ Nd7 12.Be2= [D]8/7k/3b1K1B/8/p7/p7/R7/1b6 w - - 1.Ra1 a2 2.Ke6! Ba3! 3.Bf4! Bb2 4.Be5 a3 5.Kd5! Bg6 6.Bd4 Bf7+ 7.Ke4 Bc4 8.Rg1!= It is funny too see some great engines struggling even on endpositions of some of these studies, but... Rybka shows us that endgame knowledge doesn't equal to playing strength. Best regards, George
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