52f3e717fa
In a game vs Junior, SF had the option to trade into a winning pawn endgame, and failed to do so. PGN at bottom. This FEN was one key position: 8/2Nb1k2/6pp/4Pp2/5K1P/5PP1/8/8 w - - 5 62. SF master chooses h5 here, with a fail high, which goes into the drawn KNPKB ending. With the patch, SF correctly chooses Ke3, which maintains chances to win. [Event "nTCEC - Stage 2a - Season 1"] [Site "http://www.tcec-chess.net"] [Date "2013.03.05"] [Round "11.3"] [White "Stockfish 210213"] [Black "Junior 13.3"] [Result "1/2-1/2"] [Variant "normal"] 1. d4 f5 2. g3 Nf6 3. Bg2 e6 4. c4 d5 5. Nh3 c6 6. O-O Bd6 7. Bf4 Be7 8. Nd2 O-O 9. Qb3 a5 10. Rfd1 Ne4 11. Be3 Nd7 12. Nf4 Ndf6 13. f3 a4 14. Qc2 Nxd2 15. Bxd2 dxc4 16. Qxc4 b5 17. Qc3 Qb6 18. Rac1 e5 19. Nd3 exd4 20. Qxc6 Qxc6 21. Rxc6 Bd7 22. Rcc1 Be6 23. Bb4 Rae8 24. Bxe7 Rxe7 25. Nb4 Bc4 26. Bf1 Rd7 27. Rd2 Re8 28. Rcd1 Rc7 29. Ra1 Rd8 30. Rc1 Rdd7 31. Rcd1 Re7 32. Ra1 Nd5 33. Nc2 Ne3 34. Nxd4 Bxa2 35. Nxb5 Rc5 36. Nd4 Bf7 37. Kf2 g6 38. Rd3 Nxf1 39. Kxf1 Rc4 40. b3 axb3 41. Nxb3 Kf8 42. Rd8+ Re8 43. Rxe8+ Bxe8 44. Kf2 Ke7 45. Ra7+ Bd7 46. Ke1 Rc3 47. Rb7 Rc2 48. Kd1 Rc4 49. Kd2 Kd6 50. Kd3 Rc7 51. Rxc7 Kxc7 52. Kd4 Kd6 53. Nc5 Bb5 54. e4 Be2 55. e5+ Ke7 56. Ke3 Bd1 57. Kf4 h6 58. h3 Kf7 59. h4 Bc2 60. Na6 Ba4 61. Nc7 Bd7 62. h5 g5+ 63. Ke3 Ba4 64. f4 Bd1 65. fxg5 hxg5 66. h6 Kg6 67. e6 f4+ 68. gxf4 gxf4+ 69. Kxf4 Bh5 70. Ke5 Kh7 71. Kf6 Kxh6 72. Na6 Bg4 73. e7 Bh5 74. Nc7 Bg6 75. Nd5 Be8 76. Ne3 Kh7 77. Nc4 Kh6 78. Nd2 Kh5 79. Nf3 Kg4 80. Nd4 Bh5 81. Ne6 Be8 82. Nc5 Kf3 83. Kf5 Ke3 84. Ke5 Ke2 85. Kf4 Kd2 86. Ne4+ Kd3 87. Ke5 Ke3 88. Nf6 Bf7 89. Nd5+ Kf3 90. Kf5 Ke2 91. Ke4 Be8 92. Nc3+ Kd2 93. Kd4 Kc2 94. Nd5 Kd1 95. Nf6 Bf7 96. Ne4 Be8 97. Ke3 Kc2 98. Nd6 Bd7 99. Kd4 Kd1 100. Kd3 Ba4 101. Nc4 Bb5 102. Kc3 Be8 103. Nb2+ Ke1 104. Kd3 Kf2 105. Nd1+ 1/2-1/2 No functional change (just because bench does not change)
Overview
Stockfish is a free UCI chess engine derived from Glaurung 2.1. It is not a complete chess program and requires some UCI-compatible GUI (e.g. XBoard with PolyGlot, eboard, Arena, Sigma Chess, Shredder, Chess Partner or Fritz) in order to be used comfortably. Read the documentation for your GUI of choice for information about how to use Stockfish with it.
This version of Stockfish supports up to 64 CPUs, but has not been tested thoroughly with more than 4. The program tries to detect the number of CPUs on your computer and sets the number of search threads accordingly, but please be aware that the detection is not always correct. It is therefore recommended to inspect the value of the Threads UCI parameter, and to make sure it equals the number of CPU cores on your computer. If you are using more than eight threads, it is recommended to raise the value of the Min Split Depth UCI parameter to 7.
Files
This distribution of Stockfish consists of the following files:
-
Readme.md, the file you are currently reading.
-
Copying.txt, a text file containing the GNU General Public License.
-
src/, a subdirectory containing the full source code, including a Makefile that can be used to compile Stockfish on Unix-like systems. For further information about how to compile Stockfish yourself read section below.
-
polyglot.ini, for using Stockfish with Fabien Letouzey's PolyGlot adapter.
Opening books
This version of Stockfish has support for PolyGlot opening books. For information about how to create such books, consult the PolyGlot documentation. The book file can be selected by setting the Book File UCI parameter.
Compiling it yourself
On Unix-like systems, it should be possible to compile Stockfish directly from the source code with the included Makefile.
Stockfish has support for 32 or 64-bit CPUs, the hardware POPCNT instruction, big-endian machines such as Power PC, and other platforms.
In general it is recommended to run make help to see a list of make
targets with corresponding descriptions. When not using Makefile to
compile (for instance with Microsoft MSVC) you need to manually
set/unset some switches in the compiler command line; see file types.h
for a quick reference.
Terms of use
Stockfish is free, and distributed under the GNU General Public License (GPL). Essentially, this means that you are free to do almost exactly what you want with the program, including distributing it among your friends, making it available for download from your web site, selling it (either by itself or as part of some bigger software package), or using it as the starting point for a software project of your own.
The only real limitation is that whenever you distribute Stockfish in some way, you must always include the full source code, or a pointer to where the source code can be found. If you make any changes to the source code, these changes must also be made available under the GPL.
For full details, read the copy of the GPL found in the file named Copying.txt