Author: Tord Romstad
Date: 04:45:56 02/11/06
I am currently debugging the SMP version of Glaurung. This morning, I tested it in the following position from the LCT2 test suite: [D]2r2r2/3qbpkp/p3n1p1/2ppP3/6Q1/1P1B3R/PBP3PP/5R1K w - - This position is very easy on modern hardware. Most programs find the winning move Rxh7+ in just a tiny fraction of a second. My new SMP version, however, surprised me by announcing mate in 15 after about a 18 plies and 68 seconds, and reducing this to mate in 14 two iterations later. This seems a bit suspicious to me. When using one thread, Glaurung doesn't anounce a mate even after 21 plies. Is the position really a mate in 14 moves (or less), or do I have a bug to track down? The analysis is given below: 2 +181 26 203 Bc1 Kg8 Bxa6 2 +245 26 326 Bxa6 h5 3 +279 26 1110 Bxa6 Ra8 Bd3 Rxa2 4 +185 26 3317 Bxa6 Ra8 Bd3 Kg8 4 +192 27 5267 Bc1 Kg8 Bxa6 Rb8 4 +215 28 5969 c4 Kg8 cxd5 Qxd5 Bxa6 5 +215 29 9257 c4 Kg8 cxd5 Qxd5 Bxa6 5 +873 30 11554 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Ng7 e6 Qxe6 Qxe6 6 +1201 31 17420 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Nf8 e6+ d4 exd7 Nxd7 Qxe7 7 +1295 33 27246 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bg5 Qxd7 Rc7 Qxe6 8 +1323 36 45243 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Nf8 e6+ d4 exd7 Rc7 Qxe7 Nxd7 Bxa6 9 +1326 44 97447 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bg5 Qxd7 Rc7 Qxe6 c4 bxc4 10 +1340 52 161173 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bf8 Qxd7 Rc7 Qxe6 c4 bxc4 Rb7 11 +1379 68 281072 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bg5 Qxd7 Rc7 Qxe6 c4 bxc4 dxc4 Bxc4 12 +1403 103 596597 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bf8 Qxd7 Rc7 Qxe6 c4 Qxd5 cxd3 e6+ Kh7 Qxd3+ Kg8 Qg3+ Rg7 Bxg7 Bxg7 13 +1510 179 1242976 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bf8 Qxd7 Rc7 Qxe6 c4 Bf5 Re7 Qf6+ Kg8 Be6+ Kh7 Bxd5 Rd7 Bxc4 14 +1589 302 2291408 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bf8 Qxd7 Rc7 Qxe6 Ra7 Qf6+ Kg8 e6 Rg7 e7 Rxe7 Qh8+ Kf7 Qh5+ Ke6 Qf5+ Kd6 Qxf8 d4 Bxa6 Ke6 15 +2059 876 7256632 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bh4 Qxd7 Rc7 Qxe6 Kg7 Qxd5 Kf8 e6 Ke8 Qd6 Be7 Qxc7 c4 Bxc4 16 +2243 1801 14798078 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Bf8 Qxd7 Rc7 Qxe6 Rg7 Qxd5 c4 e6 cxd3 Bxg7+ Kxg7 Qg5+ Kh8 Qh5+ Kg7 Qf7+ Kh6 Qxf8+ Kg5 Qg7+ Kf5 17 +2412 3753 31443058 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Ng5 e6+ d4 Qh5+ Kg8 exd7 Rf8 Bc1 c4 Bxc4+ Nf7 Qg4+ Kh8 Qxd4+ Kh7 Qe4+ Kg7 Qxe7 a5 Bh6+ Kg6 Qxf8 18 +9971 6875 57849904 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Ng5 e6+ d4 Qh5+ Kg8 exd7 Rd8 Qg6+ Kh8 Bc1 Rxd7 Qh6+ Kg8 Bc4+ Rd5 Bxd5+ Nf7 Qg6+ Kh8 Bxf7 Bf8 Qg8# 19 +9971 9814 82302985 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Ng5 e6+ d4 Qh5+ Kg8 exd7 Rd8 Qg6+ Kh8 Bc1 Rxd7 Qh6+ Kg8 Bc4+ Rd5 Bxd5+ Nf7 Qg6+ Kh8 Bxf7 Bf8 Qg8# 20 +9973 15488 130106000 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Ng5 e6+ d4 Qh5+ Kg8 exd7 Rd8 Qg6+ Kh8 Bc1 Rxd7 Bc4 Rd8 Qh6+ Nh7 Bd3 Kg8 Qg6+ Kh8 Qxh7# 21 +9973 28792 244255722 Rxh7+ Kxh7 Rxf7+ Rxf7 Qxg6+ Kh8 Qxf7 Ng5 e6+ d4 Qh5+ Kg8 exd7 Rd8 Qg6+ Kh8 Bc1 Rxd7 Bc4 Rd8 Qh6+ Nh7 Bd3 Kg8 Qg6+ Kh8 Qxh7# Tord
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.