X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=Readme.md;fp=Readme.md;h=0000000000000000000000000000000000000000;hp=823518d176aec11aec667cf843d6a6c9bc7f24a0;hb=84f3e867903f62480c33243dd0ecbffd342796fc;hpb=9587eeeb5ed29f834d4f956b92e0e732877c47a7 diff --git a/Readme.md b/Readme.md deleted file mode 100644 index 823518d1..00000000 --- a/Readme.md +++ /dev/null @@ -1,242 +0,0 @@ -## Overview - -[![Build Status](https://travis-ci.org/official-stockfish/Stockfish.svg?branch=master)](https://travis-ci.org/official-stockfish/Stockfish) -[![Build Status](https://ci.appveyor.com/api/projects/status/github/official-stockfish/Stockfish?branch=master&svg=true)](https://ci.appveyor.com/project/mcostalba/stockfish/branch/master) - -[Stockfish](https://stockfishchess.org) is a free, powerful UCI chess engine -derived from Glaurung 2.1. It is not a complete chess program and requires a -UCI-compatible GUI (e.g. XBoard with PolyGlot, Scid, Cute Chess, 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. - - -## 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 version 3. - - * src, a subdirectory containing the full source code, including a Makefile - that can be used to compile Stockfish on Unix-like systems. - - -## UCI parameters - -Currently, Stockfish has the following UCI options: - - * #### Debug Log File - Write all communication to and from the engine into a text file. - - * #### Contempt - A positive value for contempt favors middle game positions and avoids draws. - - * #### Analysis Contempt - By default, contempt is set to prefer the side to move. Set this option to "White" - or "Black" to analyse with contempt for that side, or "Off" to disable contempt. - - * #### Threads - The number of CPU threads used for searching a position. For best performance, set - this equal to the number of CPU cores available. - - * #### Hash - The size of the hash table in MB. It is recommended to set Hash after setting Threads. - - * #### Clear Hash - Clear the hash table. - - * #### Ponder - Let Stockfish ponder its next move while the opponent is thinking. - - * #### MultiPV - Output the N best lines (principal variations, PVs) when searching. - Leave at 1 for best performance. - - * #### Skill Level - Lower the Skill Level in order to make Stockfish play weaker (see also UCI_LimitStrength). - Internally, MultiPV is enabled, and with a certain probability depending on the Skill Level a - weaker move will be played. - - * #### UCI_LimitStrength - Enable weaker play aiming for an Elo rating as set by UCI_Elo. This option overrides Skill Level. - - * #### UCI_Elo - If enabled by UCI_LimitStrength, aim for an engine strength of the given Elo. - This Elo rating has been calibrated at a time control of 60s+0.6s and anchored to CCRL 40/4. - - * #### UCI_ShowWDL - If enabled, show approximate WDL statistics as part of the engine output. - These WDL numbers model expected game outcomes for a given evaluation and - game ply for engine self-play at fishtest LTC conditions (60+0.6s per game). - - * #### Move Overhead - Assume a time delay of x ms due to network and GUI overheads. This is useful to - avoid losses on time in those cases. - - * #### Slow Mover - Lower values will make Stockfish take less time in games, higher values will - make it think longer. - - * #### nodestime - Tells the engine to use nodes searched instead of wall time to account for - elapsed time. Useful for engine testing. - - * #### UCI_Chess960 - An option handled by your GUI. If true, Stockfish will play Chess960. - - * #### UCI_AnalyseMode - An option handled by your GUI. - - * #### SyzygyPath - Path to the folders/directories storing the Syzygy tablebase files. Multiple - directories are to be separated by ";" on Windows and by ":" on Unix-based - operating systems. Do not use spaces around the ";" or ":". - - Example: `C:\tablebases\wdl345;C:\tablebases\wdl6;D:\tablebases\dtz345;D:\tablebases\dtz6` - - It is recommended to store .rtbw files on an SSD. There is no loss in storing - the .rtbz files on a regular HD. It is recommended to verify all md5 checksums - of the downloaded tablebase files (`md5sum -c checksum.md5`) as corruption will - lead to engine crashes. - - * #### SyzygyProbeDepth - Minimum remaining search depth for which a position is probed. Set this option - to a higher value to probe less agressively if you experience too much slowdown - (in terms of nps) due to TB probing. - - * #### Syzygy50MoveRule - Disable to let fifty-move rule draws detected by Syzygy tablebase probes count - as wins or losses. This is useful for ICCF correspondence games. - - * #### SyzygyProbeLimit - Limit Syzygy tablebase probing to positions with at most this many pieces left - (including kings and pawns). - - -## What to expect from Syzygybases? - -If the engine is searching a position that is not in the tablebases (e.g. -a position with 8 pieces), it will access the tablebases during the search. -If the engine reports a very large score (typically 153.xx), this means -that it has found a winning line into a tablebase position. - -If the engine is given a position to search that is in the tablebases, it -will use the tablebases at the beginning of the search to preselect all -good moves, i.e. all moves that preserve the win or preserve the draw while -taking into account the 50-move rule. -It will then perform a search only on those moves. **The engine will not move -immediately**, unless there is only a single good move. **The engine likely -will not report a mate score even if the position is known to be won.** - -It is therefore clear that this behaviour is not identical to what one might -be used to with Nalimov tablebases. There are technical reasons for this -difference, the main technical reason being that Nalimov tablebases use the -DTM metric (distance-to-mate), while Syzygybases use a variation of the -DTZ metric (distance-to-zero, zero meaning any move that resets the 50-move -counter). This special metric is one of the reasons that Syzygybases are -more compact than Nalimov tablebases, while still storing all information -needed for optimal play and in addition being able to take into account -the 50-move rule. - -## Large Pages - -Stockfish supports large pages on Linux and Windows. Large pages make -the hash access more efficient, improving the engine speed, especially -on large hash sizes. Typical increases are 5..10% in terms of nps, but -speed increases up to 30% have been measured. The support is -automatic. Stockfish attempts to use large pages when available and -will fall back to regular memory allocation when this is not the case. - -### Support on Linux - -Large page support on Linux is obtained by the Linux kernel -transparent huge pages functionality. Typically, transparent huge pages -are already enabled and no configuration is needed. - -### Support on Windows - -The use of large pages requires "Lock Pages in Memory" privilege. See -[Enable the Lock Pages in Memory Option (Windows)](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows) -on how to enable this privilege. Logout/login may be needed -afterwards. Due to memory fragmentation, it may not always be -possible to allocate large pages even when enabled. A reboot -might alleviate this problem. To determine whether large pages -are in use, see the engine log. - -## Compiling Stockfish yourself from the sources - -Stockfish has support for 32 or 64-bit CPUs, certain hardware -instructions, big-endian machines such as Power PC, and other platforms. - -On Unix-like systems, it should be easy to compile Stockfish -directly from the source code with the included Makefile in the folder -`src`. In general it is recommended to run `make help` to see a list of make -targets with corresponding descriptions. - -``` - cd src - make help - make build ARCH=x86-64-modern -``` - -When not using the 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. - -When reporting an issue or a bug, please tell us which version and -compiler you used to create your executable. These informations can -be found by typing the following commands in a console: - -``` - ./stockfish - compiler -``` - -## Understanding the code base and participating in the project - -Stockfish's improvement over the last couple of years has been a great -community effort. There are a few ways to help contribute to its growth. - -### Donating hardware - -Improving Stockfish requires a massive amount of testing. You can donate -your hardware resources by installing the [Fishtest Worker](https://github.com/glinscott/fishtest/wiki/Running-the-worker:-overview) -and view the current tests on [Fishtest](https://tests.stockfishchess.org/tests). - -### Improving the code - -If you want to help improve the code, there are several valuable resources: - -* [In this wiki,](https://www.chessprogramming.org) many techniques used in -Stockfish are explained with a lot of background information. - -* [The section on Stockfish](https://www.chessprogramming.org/Stockfish) -describes many features and techniques used by Stockfish. However, it is -generic rather than being focused on Stockfish's precise implementation. -Nevertheless, a helpful resource. - -* The latest source can always be found on [GitHub](https://github.com/official-stockfish/Stockfish). -Discussions about Stockfish take place in the [FishCooking](https://groups.google.com/forum/#!forum/fishcooking) -group and engine testing is done on [Fishtest](https://tests.stockfishchess.org/tests). -If you want to help improve Stockfish, please read this [guideline](https://github.com/glinscott/fishtest/wiki/Creating-my-first-test) -first, where the basics of Stockfish development are explained. - - -## Terms of use - -Stockfish is free, and distributed under the **GNU General Public License version 3** -(GPL v3). 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 v3 found in the file named -*Copying.txt*.