Author: Ed Schröder
Date: 03:40:30 08/13/99
Go up one level in this thread
>Posted by James Robertson on August 13, 1999 at 03:10:30: > >Today my program encountered JPCrafty in a computer tournament at FICS. In this >position: > >r1b2rk1/4b2p/p1p1p2Q/2q1ppN1/8/8/4B1PP/3R1RK1 w - - id JPCrafty - JRCP, 1999; > >JPCrafty played Rf2 and the game was drawn by perpetual check after 1... Bxg5 2. >Qxg5+ Kh8 3. Rd8 Rxd8 4. Qxd8+ etc. I was analyzing the game afterwards with >Fritz and found that it very quickly saw Rf2 as a draw, but decided that Kh1 was >actually better for white, although just a fraction of a pawn. A bit more >analysis shows that black is lost(!) after 1. Kh1 Bxg5 2. Qxg5+ Kh8 3. Rd8 Rxd8 >4. Qxd8+ Kg7 5. Qg5+ Kf8 6. Rd1! > >Crafty 16.11 sees Rf2 as a draw at 10 plies, and sticks with it for a long time >after (I don't know how long, as my computer is slow and I only let it think for >several minutes). > >My program sees neither the draw nor the win but picks Kh1 after 11 plies for >some positional reason. What do other programs think? Here is Rebel's analysis. Ed Schroder ----------------------------- Thinking.... +---+---+---+---+---+---+---+---+ AM Kh1 - Kh1 loses? 8 | *R| | *B| | | *R| *K| | +---+---+---+---+---+---+---+---+ 00:00:00 00:00:00 7 | | | | | *B| | | *p| +---+---+---+---+---+---+---+---+ 6 | *p| | *p| | *p| | | Q | Time infinite +---+---+---+---+---+---+---+---+ Hash 60 Mb 5 | | | *Q| | *p| *p| N | | Engine Rebel Century +---+---+---+---+---+---+---+---+ Personality Rebel Century 4 | | | | | | | | | anti-GM Off +---+---+---+---+---+---+---+---+ System Tiger Off 3 | | | | | | | | | Combination Off +---+---+---+---+---+---+---+---+ Style Normal 2 | | | | | B | | p | p | Strength Strongest +---+---+---+---+---+---+---+---+ Search Normal Search 1 | | | | R | | R | K | | +---+---+---+---+---+---+---+---+ a b c d e f g h r1b2rk1/4b2p/p1p1p2Q/2q1ppN1/8/8/4B1PP/3R1RK1 w - - [Event "?"] [Site "?"] [Date "??.??.????"] [Round "?"] [White "AM Kh1"] [Black "Kh1 loses"] [Result "*"] [WhiteElo "?"] [BlackElo "?"] [FEN "r1b2rk1/4b2p/p1p1p2Q/2q1ppN1/8/8/4B1PP/3R1RK1 w - - 0 1"] 1.* 00:00:00 1.27 -7.69 1.Rd4 Qxd4+ 2.Kh1 Bxg5 3.Qxg5+ Kh8 00:00:00 1.32 -2.57 1.Rf2 Bxg5 2.Qxg5+ Kh8 00:00:00 1.34 -2.23 1.Kh1 Bxg5 2.Qxg5+ Kh8 00:00:00 2.00 -2.23 1.Kh1 Bxg5 2.Qxg5+ Kh8 00:00:00 3.00 -2.17 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rc1 Qb6 4.Rfd1 (0) 00:00:00 4.00 -1.93 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 Rb8 4.Qf6+ Kg8 (0) 00:00:01 5.00 0.00 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 h5 4.Qxh5+ Kg8 5.Qg6 Kh8 6.Qh5+ Kg8 7.Qg6 Kh8 (0) 00:00:01 6.00 0.00 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 Rxd8 4.Qxd8+ Kg7 5.Qg5+ Kf8 6.Qd8+ Kg7 7.Qg5+ Kf8 8.Qd8+ (1) 00:00:02 7.00 0.00 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 Rxd8 4.Qxd8+ Kg7 5.Qg5+ Kf8 6.Qd8+ Kg7 7.Qg5+ Kf8 8.Qd8+ (2) 00:00:06 8.00 0.00 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 Rxd8 4.Qxd8+ Kg7 5.Qg5+ Kf8 6.Qd8+ Kg7 7.Qg5+ Kf8 8.Qd8+ (3) 00:00:27 9.00 1.56 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 Rb8 4.Qf6+ Kg8 5.Bh5 Rb7 6.Rxc8+ Rxc8 7.Qxe6+ Kg7 8.Qxc8 (13) 00:00:54 10.00 2.02 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 f4+ 4.Rfd1 h6 5.Qxh6+ (31) 00:02:12 11.00 2.43 1.Kh1 Bxg5 2.Qxg5+ Kh8 3.Rd8 Rb8 4.Bxa6 Rxd8 5.Qxd8+ Kg7 6.Bxc8 Rxc8 7.Qd7+ Kf6 8.Qxc8 Qb5 (68) Positions : 28.621.835 Nodes per second : 198.762 Extensions (checks) : 4.100.435 (14%) Extensions (captures) : 192.029 (0%) Extensions (king safety) : 272.044 (0%) Extensions (on depth) : 214.297 (0%) Extensions (remaining) : 52.948 (0%) Extensions (total) : 4.831.753 (16%) Hash Table : 715.210 653.084 (83%) Average depth : 16 Deepest depth : 57 >James > >My program's thoughts (P233, 4MB hash): > >Depth Score Time Nodes PV > 1 -335 0 17 Rf2 > 2 -321 0 129 Rf2 Bxg5 Qxg5+ > 3 -332 0 508 Rf2 Bxg5 Qxg5+ Kh8 Qh6 > 4 -332 60 1485 Rf2 Bxg5 Qxg5+ Kh8 Qh6 > 5 -357 60 5411 Rf2 Bxg5 Qxg5+ Kh8 Qh6 e4 > 6 -347 170 15306 Rf2 Bxg5 Qxg5+ Kh8 Qh6 e4 Bc4 > 7 -341 390 31875 Rf2 Bxg5 Qxg5+ Kh8 Rd8 Rxd8 Qxd8+ Kg7 Bxa6 >Rxa6 Qxc8 > 8 -339 720 69746 Rf2 Bxg5 Qxg5+ Kh8 Rc1 Qd5 Rd1 Qe4 Qh6 > 9 -316 3080 304177 Rf2 Bxg5 Qxg5+ Kh8 Bf3 f4 Qh6 Kg8 Be4 Rf7 > 10> -299 16370 1613873 Kh1 Bxg5 Qxg5+ Kh8 Bf3 Ra7 Rc1 Qe7 Qxe7 Rxe7 >Bxc6 e4 > 10 -299 16370 1613873 Kh1 Bxg5 Qxg5+ Kh8 Bf3 Ra7 Rc1 Qe7 Qxe7 Rxe7 >Bxc6 e4 > 11 -248 46140 4714326 Kh1 Bxg5 Qxg5+ Kh8 Rd8 Rxd8 Qxd8+ Kg7 Qg5+ >Kf8 Qf6+ Kg8 Rd1 h6 Qxh6
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