List of chess engines
Encyclopedia
A chess engine is a computer program
that can play the game of chess
.
(GUI) but are rather console application
s that communicate with a GUI such as XBoard
(Linux
), WinBoard (Windows
) or Arena
(Windows
) via a standard protocol.
became the initial de facto standard, called the Chess Engine Communication Protocol
and first supported by XBoard
. When XBoard was ported to the Windows operating system as WinBoard this protocol was popularly renamed to 'WinBoard Protocol'. The WinBoard Protocol was itself upgraded and the two versions of the protocols are referred to as: 'WinBoard Protocol 1' (original version) and 'WinBoard Protocol 2' (newer version). There is another protocol, the Universal Chess Interface
. Some engines support both major protocols, and each protocol has its supporters. The Winboard Protocol is more popular but many chess engine developers feel that the Universal Chess Interface is easier to implement. Some interface programs, such as Arena, support both protocols whereas others, such as WinBoard, support only one and depend on subsidiary interpretors, such as Polyglot, to translate.
Some chess engines use endgame tablebase
s to increase their playing strength during the endgame. An endgame tablebase is a database of all possible endgame positions with small groups of material. Each position is conclusively determined as a win, loss, or draw for the player whose turn it is to move, and the number of moves to the end with best play by both sides. Endgame tablebases in all cases identify the absolute best move in all positions included (identifying the move that wins fastest against perfect defense, or the move that loses slowest against optimal opposition). Such tablebases are available for all positions containing three to six pieces (counting the kings
) and for some seven-piece combinations. When the maneuvering in an ending to achieve an irreversible improvement takes more moves than the horizon of calculation of a chess engine, an engine is not guaranteed to find the best move without the use of an endgame tablebase, and in many cases can fall foul of the fifty-move rule as a result.
Many engines use permanent brain
as a method to increase their strength.
Most tournaments also allow any types of hardware, so only engine/hardware combinations are being compared.
Historically, commercial programs have been the strongest engines. To some extent, this is a self-fulfilling prophecy
; if an amateur engine wins a tournament or otherwise performs well (for example, Zappa
in 2005), then it is quickly commercialized. Titles gained in these tournaments garner much prestige for the winning programs, and are thus used for marketing purposes.
There are a number of factors that vary among the chess engine rating lists:
These differences affect the results, and make direct comparisons between rating lists difficult.
These ratings, although calculated by using the Elo system
(or similar rating methods), have no direct relation to FIDE Elo ratings or to other chess federation ratings of human players. Except for some man versus machine games which the SSDF had organized many years ago (which were far from today's level), there is no calibration between any of these rating lists and player pools. Hence, the results which matter are the ranks and the differences between the ratings, not the absolute level of the numbers. Also, each list calibrates their Elo via a different method. Therefore no Elo comparisons can be made between the lists. Nevertheless, in view of recent man versus machine matches, it is generally undisputed that top computer chess engines should be rated at least in the range of top human performances, and probably significantly higher.
Missing from many rating lists are IPPOLIT and its derivatives (e.g. Fire http://www.chesslogik.com/Fire.htm). Although very strong and open source
, there are allegations from commercial software interests that they were derived from disassembled binary of Rybka
. Due to the controversy, all these engines have been blacklisted from many tournaments and rating lists. Although Rybka has been accused of being based on Fruit
, it is not blacklisted from computer chess tournaments or rating lists. In June 2011, Rybka was found guilty of being derived from Fruit and Crafty and Rybka has been banned from the ICGA (International Computer Games Association) World Computer Chess Championship, and its previous victories (2007, 2008, 2009, and 2010) has been revoked. As a consequence of this some of the rating lists will stop including Rybka in their lists. On the other hand, the SWCR list was discontinued in September 2011. This was fallout from an open letter in which many top programs boycotted tournaments run by the CSVN, namely the Dutch Open Computer Chess Championship
, for allowing Rybka
to participate.
Also missing from some rating lists is Houdini
, a very strong free engine by Robert Houdart that appeared in the middle of 2010. Houdini 1.5a has taken the top spot in the rating lists that include it.
test suite, for instance, focuses on deep sacrifices. Then there are the BT2450 and BT2630 test suites by Hubert Bednorz and Fred Toennissen. These suites measure the tactical capability of the engine and have been used at least by REBEL
. There is also a general test suite called Brilliancy by Dana Turnmire. The suite has been compiled mostly from How to Reassess Your Chess Workbook.
Strategic Test Suite (STS) by Swaminathan and Dann Corbit, tests chess engine's strategical strength.
chess programs were expressly written to teach the craft of chess programming.
There is also source-available proprietary software.
These small programs are written for hobby or to win programming contests, currently able to play all legal chess moves although with limited text interface.
s. All are historical; chess supercomputers have not competed in computer tournaments since Hydra played in 2006.
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
that can play the game of chess
Chess
Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...
.
Interface
Most chess engines do not have their own graphical user interfaceGraphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
(GUI) but are rather console application
Console application
A console application is a computer program designed to be used via a text-only computer interface, such as a text terminal, the command line interface of some operating systems or the text-based interface included with most Graphical User Interface operating systems, such as the Win32 console in...
s that communicate with a GUI such as XBoard
XBoard
XBoard and WinBoard are free graphical user interface clients. Originally developed by Tim Mann, these programs are compatible with various chess engines that support the Chess Engine Communication Protocol such as GNU Chess...
(Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
), WinBoard (Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
) or Arena
Arena
An arena is an enclosed area, often circular or oval-shaped, designed to showcase theater, musical performances, or sporting events. It is composed of a large open space surrounded on most or all sides by tiered seating for spectators. The key feature of an arena is that the event space is the...
(Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
) via a standard protocol.
Protocols
The command line interface of GNU ChessGNU Chess
GNU Chess is a computer program which plays a full game of chess against a human or other computer program.GNU Chess is one of the oldest computer chess programs for Unix-based computers and one of the earliest available with full source code....
became the initial de facto standard, called the Chess Engine Communication Protocol
Chess Engine Communication Protocol
The Chess Engine Communication Protocol is an open communication protocol that enables a chess engine to communicate with its user interface....
and first supported by XBoard
XBoard
XBoard and WinBoard are free graphical user interface clients. Originally developed by Tim Mann, these programs are compatible with various chess engines that support the Chess Engine Communication Protocol such as GNU Chess...
. When XBoard was ported to the Windows operating system as WinBoard this protocol was popularly renamed to 'WinBoard Protocol'. The WinBoard Protocol was itself upgraded and the two versions of the protocols are referred to as: 'WinBoard Protocol 1' (original version) and 'WinBoard Protocol 2' (newer version). There is another protocol, the Universal Chess Interface
Universal Chess Interface
The Universal Chess Interface is an open communication protocol that enables a chess program's engine to communicate with its user interface....
. Some engines support both major protocols, and each protocol has its supporters. The Winboard Protocol is more popular but many chess engine developers feel that the Universal Chess Interface is easier to implement. Some interface programs, such as Arena, support both protocols whereas others, such as WinBoard, support only one and depend on subsidiary interpretors, such as Polyglot, to translate.
Increasing strength
Chess engines increase in playing strength each year. This is partly due to the increase in processing power that enables calculations to be made to ever greater depths in a given time. In addition, programming techniques have improved, enabling the engines to be more selective in the lines that they analyse and to acquire a better positional understanding.Some chess engines use endgame tablebase
Endgame tablebase
An endgame tablebase is a computerized database that contains precalculated exhaustive analysis of a chess endgame position. It is typically used by a computer chess engine during play, or by a human or computer that is retrospectively analysing a game that has already been played.The tablebase...
s to increase their playing strength during the endgame. An endgame tablebase is a database of all possible endgame positions with small groups of material. Each position is conclusively determined as a win, loss, or draw for the player whose turn it is to move, and the number of moves to the end with best play by both sides. Endgame tablebases in all cases identify the absolute best move in all positions included (identifying the move that wins fastest against perfect defense, or the move that loses slowest against optimal opposition). Such tablebases are available for all positions containing three to six pieces (counting the kings
King (chess)
In chess, the king is the most important piece. The object of the game is to trap the opponent's king so that its escape is not possible . If a player's king is threatened with capture, it is said to be in check, and the player must remove the threat of capture on the next move. If this cannot be...
) and for some seven-piece combinations. When the maneuvering in an ending to achieve an irreversible improvement takes more moves than the horizon of calculation of a chess engine, an engine is not guaranteed to find the best move without the use of an endgame tablebase, and in many cases can fall foul of the fifty-move rule as a result.
Many engines use permanent brain
Permanent brain
In turn-based games, permanent brain is the act of thinking during the opponent's turn.Turn-based games such as chess have a weakness: one of the players can spend too much time thinking. Time control solves this problem: each player receives certain amount of time for thinking...
as a method to increase their strength.
Tournaments
The results of computer tournaments give one view of the relative strengths of chess engines. However, tournaments do not play a statistically significant number of games for accurate strength determination. In fact, the number of games that need to be played between fairly evenly matched engines, in order to achieve significance, runs into the thousands and is, therefore, impractical within the framework of a tournament http://www.mizarchessengine.com/columns/testing-a-chess-engine/.Most tournaments also allow any types of hardware, so only engine/hardware combinations are being compared.
Historically, commercial programs have been the strongest engines. To some extent, this is a self-fulfilling prophecy
Self-fulfilling prophecy
A self-fulfilling prophecy is a prediction that directly or indirectly causes itself to become true, by the very terms of the prophecy itself, due to positive feedback between belief and behavior. Although examples of such prophecies can be found in literature as far back as ancient Greece and...
; if an amateur engine wins a tournament or otherwise performs well (for example, Zappa
Zappa (chess)
Zappa is a chess engine written by Anthony Cozzie, a graduate student at the University of Illinois at Urbana-Champaign. The program emphasizes sound search and a good use of multiple processors....
in 2005), then it is quickly commercialized. Titles gained in these tournaments garner much prestige for the winning programs, and are thus used for marketing purposes.
- World Computer Chess ChampionshipWorld Computer Chess ChampionshipWorld Computer Chess Championship is an annual event where computer chess engines compete against each other. The event is organized by the International Computer Games Association...
- World Computer Speed Chess ChampionshipWorld Computer Speed Chess ChampionshipWorld Computer Speed Chess Championship is an annual event where computer chess engines compete against each other at blitz chess time controls. It is held in conjunction with the World Computer Chess Championship...
- World Computer Speed Chess Championship
- Dutch open computer chess championshipDutch open computer chess championshipThe Dutch open computer chess championship is a chess tournament for computer chess programs. It is organised yearly by the CSVN around October or November...
- Internet Computer Chess TournamentInternet Computer Chess TournamentThe Internet Computer Chess Tournament has been held annually since 2000 on the Internet Chess Club. Unlike other computer chess competitions, there are no travel requirements so there is usually broad participation...
(CCT) - International Paderborn Computer Chess ChampionshipInternational Paderborn Computer Chess ChampionshipThe International Paderborn Computer Chess Championship is an annual chess tournament for computer chess programs. It is organised yearly by the university of Paderborn...
- North American Computer Chess ChampionshipNorth American Computer Chess ChampionshipThe North American Computer Chess Championship was a computer chess championship held from 1970 to 1994. It was organised by the Association for Computing Machinery and by Dr. Monty Newborn, Professor of Computer Science at McGill University. It was one of the first computer chess tournaments. The...
Ratings
Chess engine rating lists aim to provide statistically significant measures of relative engine strength. These lists play multiple games between engines on standard hardware platforms, so that processor differences are factored out. Some also standardize the opening books, in an attempt to measure the strength differences of the engines only. These lists not only provide a ranking, but also margins of error on the given ratings. Also rating lists typically play games continuously, publishing many updates per year, compared to tournaments which only take place annually.There are a number of factors that vary among the chess engine rating lists:
- Time control. Longer time controls, such as 40 moves in 120 minutes, are better suited for determining tournament play strength, but also make testing more time-consuming.
- Hardware used. Faster hardware with more memory leads to stronger play.
- 64-bit (vs. 32-bit) hardware and operating systems favor bitboardBitboardA bitboard is a data structure commonly used in computer systems that play board games.A bitboard, often used for boardgames such as chess, checkers and othello, is a specialization of the bitset data structure, where each bit represents a game position or state, designed for optimization of speed...
-based programs - Multiprocessor vs. single processor hardware.
- Ponder settings (speculative analysis while the opponent is thinking) aka Permanent Brain.
- Transposition table sizes.
- Opening book settings.
These differences affect the results, and make direct comparisons between rating lists difficult.
| Rating list | Time control Time control A time control is a mechanism in the tournament play of almost all two-player board games so that each round of the match can finish in a timely way and the tournament can proceed. Time controls are typically enforced by means of a game clock... (moves/minutes) |
Year started |
Last updated | Engine/platform entries |
Games played |
Top three engines | Rating |
|---|---|---|---|---|---|---|---|
| CCRL | 40/40 Ponder OFF |
2005 | July 31, 2011 | 225 | 334,153 | Houdini Houdini (chess) Houdini is a chess engine for Windows, by Belgian programmer Robert Houdart. Free for non-commercial use , later versions are not free. Since the release of version 1.5 on 15 December 2010, it has taken the top spot in every rating list that includes it... 1.5a x64 64-bit 64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s... 4CPU Central processing unit The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in... Rybka Rybka Rybka is a computer chess engine designed by International Master Vasik Rajlich. , Rybka is one of the top-rated engines on chess engine rating lists and has won many computer chess tournaments... 4.1 x64 4CPU Stockfish Stockfish (chess) Stockfish is an open source chess engine, developed by Tord Romstad, Joona Kiiski and Marco Costalba and licensed under the GNU General Public License version 3. The current version 2.1.1 is available as C++ source code, and also has precompiled versions for Microsoft Windows, Mac OS X Snow... 2.1.1 x64 4CPU |
3308 3271 3245 |
| CEGT | 40/20 Ponder OFF |
2006 | July 31, 2011 | 923 | 528,034 | Houdini 1.5a x64 6CPU Deep Rybka 4.1 x64 4CPU Critter 1.2 x64 4CPU |
3292 3245 3242 |
| IPON | 5m+3s ~16min/game Ponder ON |
2006 | October 24th, 2011 | 93 | 156,400 | Houdini 2.0 STD 1CPU Komodo64 3 1CPU Deep Rybka 4.1 1CPU |
3022 2966 2956 |
| SSDF Swedish Chess Computer Association The Swedish Chess Computer Association is an organization that tests computer chess software by playing chess programs against one another and producing a rating list. On September 26, 2008, the list was released with Deep Rybka 3 leading with an estimated Elo rating of 3238. Rybka's listing in... |
40/120 Ponder ON |
1984 | May 11, 2011 | 311 | 120,010 | Deep Rybka 4 x64 4CPU Naum Naum (chess) Naum is a computer chess engine by Aleksandar Naumov . The current version 4.2 was released in March 2010. The commercial distribution is "engine only" on the website of the programmer. The program supports both UCI and Winboard and can therefore be operated under different graphical interfaces... 4.2 x64 4CPU Deep Shredder Shredder (chess) Shredder is a commercial chess program developed in Germany by Stefan Meyer-Kahlen in 1993. Shredder won the World Microcomputer Chess Championship in 1996 and 2000, the World Computer Chess Championship in 1999 and 2003, the World Computer Speed Chess Championship in 2002, 2003, 2004, 2005, and... 12 x64 4CPU |
3216 3155 3115 |
| WBEC | 40/40 Ponder ON |
2001 | May 15, 2011 | 226 (Historically: 850+) |
100,749 | Rybka 4 x64 2CPU Stockfish 2.0.1 x64 2CPU Thinker 5.5.4A1 x64 2CPU |
3124 3121 3114 |
- Note that the listings in the above table only count the best entry for a given engine.
These ratings, although calculated by using the Elo system
Elo rating system
The Elo rating system is a method for calculating the relative skill levels of players in two-player games such as chess. It is named after its creator Arpad Elo, a Hungarian-born American physics professor....
(or similar rating methods), have no direct relation to FIDE Elo ratings or to other chess federation ratings of human players. Except for some man versus machine games which the SSDF had organized many years ago (which were far from today's level), there is no calibration between any of these rating lists and player pools. Hence, the results which matter are the ranks and the differences between the ratings, not the absolute level of the numbers. Also, each list calibrates their Elo via a different method. Therefore no Elo comparisons can be made between the lists. Nevertheless, in view of recent man versus machine matches, it is generally undisputed that top computer chess engines should be rated at least in the range of top human performances, and probably significantly higher.
Missing from many rating lists are IPPOLIT and its derivatives (e.g. Fire http://www.chesslogik.com/Fire.htm). Although very strong and open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
, there are allegations from commercial software interests that they were derived from disassembled binary of Rybka
Rybka
Rybka is a computer chess engine designed by International Master Vasik Rajlich. , Rybka is one of the top-rated engines on chess engine rating lists and has won many computer chess tournaments...
. Due to the controversy, all these engines have been blacklisted from many tournaments and rating lists. Although Rybka has been accused of being based on Fruit
Fruit (chess)
Fruit is a chess engine developed by Fabien Letouzey. In the SSDF rating list released on November 24, 2006, Fruit version 2.2.1 had a rating of 2842...
, it is not blacklisted from computer chess tournaments or rating lists. In June 2011, Rybka was found guilty of being derived from Fruit and Crafty and Rybka has been banned from the ICGA (International Computer Games Association) World Computer Chess Championship, and its previous victories (2007, 2008, 2009, and 2010) has been revoked. As a consequence of this some of the rating lists will stop including Rybka in their lists. On the other hand, the SWCR list was discontinued in September 2011. This was fallout from an open letter in which many top programs boycotted tournaments run by the CSVN, namely the Dutch Open Computer Chess Championship
Dutch open computer chess championship
The Dutch open computer chess championship is a chess tournament for computer chess programs. It is organised yearly by the CSVN around October or November...
, for allowing Rybka
Rybka
Rybka is a computer chess engine designed by International Master Vasik Rajlich. , Rybka is one of the top-rated engines on chess engine rating lists and has won many computer chess tournaments...
to participate.
Also missing from some rating lists is Houdini
Houdini (chess)
Houdini is a chess engine for Windows, by Belgian programmer Robert Houdart. Free for non-commercial use , later versions are not free. Since the release of version 1.5 on 15 December 2010, it has taken the top spot in every rating list that includes it...
, a very strong free engine by Robert Houdart that appeared in the middle of 2010. Houdini 1.5a has taken the top spot in the rating lists that include it.
Test suites
Engines can be tested by measuring their performance on specific positions. Typical is the use of test suites, where for each given position there is one best move to find. These positions can be geared towards positional, tactical or endgame play. The NolotNolot
Nolot is a chess test suite with 11 very difficult positions from real games. They were compiled by Pierre Nolot for the French chess magazine Gambisco and posted on the rec.games.chess Usenet group in 1994. Some of these positions are particularly hard to solve for chess engines.-Problem 1 :FEN:...
test suite, for instance, focuses on deep sacrifices. Then there are the BT2450 and BT2630 test suites by Hubert Bednorz and Fred Toennissen. These suites measure the tactical capability of the engine and have been used at least by REBEL
REBEL (chess)
REBEL was a world champion chess program developed by Ed Schröder. Development of REBEL started in 1980 on a TRS-80, and it was ported many times to dedicated hardware and the fastest microprocessors of the day:...
. There is also a general test suite called Brilliancy by Dana Turnmire. The suite has been compiled mostly from How to Reassess Your Chess Workbook.
Strategic Test Suite (STS) by Swaminathan and Dann Corbit, tests chess engine's strategical strength.
Freely available
There are hundreds of freely available chess engines which conform to one of the above communication protocols. Many run on Windows or are open source. The top 50 strongest, freely available engines are listed here. Others may be found by examining the rating lists or external links.| Engine (strongest version) | Author (Country) | Elo |
|---|---|---|
| Alaric v707 | Peter Fendrich (Sweden) | 2763 |
| Bison v9.11 | Ivan Bonkin (Russia) | 2825 |
| Booot v5.1.0 | Alex Morozov (Ukraine) | 2951 |
| Bright v0.4a | Allard Siemelink (Netherlands) | 3003 (4CPU) |
| BugChess2 v1.7 | Francois and Jean-Philippe Karr (France) | 2800 (32-bit) |
| Chronos v1.9.9 | Guillermo Filia (Argentina) | 2849 (64-bit) |
| Colossus 2008b | Martin Bryant Martin Bryant (programmer) Martin Bryant is a British computer programmer known as the author of Colossus Chess, a 1980s commercial chess-playing program, and Colossus Draughts, gold medal winner at the 2nd Computer Olympiad in 1990.- Computer chess :... (England) |
2745 |
| Crafty Crafty Crafty is a chess program written by UAB professor Dr. Robert Hyatt. It is directly derived from Cray Blitz, winner of the 1983 and 1986 World Computer Chess Championships.... v23.3 |
Robert Hyatt Robert Hyatt Dr. Robert Hyatt is an Associate Professor of Computer science at the University of Alabama at Birmingham, in the Department of Computer and Information Sciences . He is the author of the computer chess program Crafty and the co-author of Cray Blitz, a two-time winner of the World Computer Chess... (US) |
2950 (64-bit 4CPU) |
| Critter v1.2 | Richard Vida (Slovakia) | 3305 (64-bit 4CPU) |
| Cyclone v3.4 | Fabien Letouzey (France), Thomas Gaksch, Norman Schmidt | 2971 (2CPU) |
| Cyrano v0.6b17 | Harald Johnsen (France) | 2748 |
| Daydreamer v1.75 | Aaron Becker (USA) | 2783 (32-bit) |
| Delfi Delfi Delfi is a Winboard/UCI chess engine written in Pascal designed by Italian chess programmer Fabio Cavicchio. It is designed to emulate a human playing style and is rated . The latest released version is 5.4. Source code for version 5.1 is available.... v5.4 |
Fabio Cavicchio (Italy) | 2825 (2CPU) |
| Deuterium 10.01.27.213 | Ferdinand Mosca (Philippines) | 2770 |
| Doch v1.2 | Don Dayley (USA) | 2991 (64-bit) |
| E.T. Chess 13.01.08 | Eric Triki (France) | 2749 |
| Fire v1.31 | Norman Schmidt (USA) | 3260 |
| Frenzee Feb08 | Sune Fischer (Denmark) | 2799 (32-bit) |
| Fruit Fruit (chess) Fruit is a chess engine developed by Fabien Letouzey. In the SSDF rating list released on November 24, 2006, Fruit version 2.2.1 had a rating of 2842... v2.3.1 |
Fabien Letouzey (France), Ryan Benitez (USA) | 2887 |
| Glaurung v2.2 | Tord Romstad (Norway) | 3003 (64-bit 4CPU) |
| Grapefruit v1.0 | Fabien Letouzey (France), Thomas Gaksch (Germany), Vadim Demichev | 2977 (32-bit 2CPU) |
| Gull v1.2 | Vadim Demichev (Russia) | 3038 (64-bit) |
| Hamsters v0.7.1 | Alessandro Scotti (Italy) | 2723 |
| Hannibal v1.0a | Edsel Apostol (Philippines), Sam Hamilton (USA) | 2941 (64-bit) |
| Houdini Houdini (chess) Houdini is a chess engine for Windows, by Belgian programmer Robert Houdart. Free for non-commercial use , later versions are not free. Since the release of version 1.5 on 15 December 2010, it has taken the top spot in every rating list that includes it... v1.5a |
Robert Houdart (Belgium) | 3309 |
| IvanHoe v9.47b | Yakov Petrovich Golyadkin, Igor Igorovich Igoronov, Robert Pescatore, Yusuf Ralf Weisskopf, Ivan Skavinsky Skavar | 3270 |
| Jonny v4.00 | Johannes Zwanzger (Germany) | 2955 (4CPU) |
| Komodo v3.0 | Don Dailey | 3280 (64-bit) |
| List v5.12 (last free version) |
Fritz Reul (Germany) | 2720 |
| Loop 13.6 (Loop 2007) (last free version) |
Fritz Reul (Germany) | 2943 (64-bit 4CPU) |
| Movei v00.8.438 (10 10 10) | Uri Blass (Israel) | 2773 |
| Naraku v1.4 | Marco Meloni (Italy) | 2820 |
| Naum v2.0 (last free version) |
Aleksandar Naumov (Serbia/Canada) | 2802 (64-bit) |
| Pharaon v3.5.1 | Franck Zibi (France) | 2744 (2CPU) |
| Pro Deo v1.2 (freeware version of the commercial program Rebel) |
Ed Schröder (Netherlands) | 2720 |
| Protector v1.3.6 | Raimund Heid (Germany) | 3070 (64-bit) |
| Rybka v.2.2n2 (last free version) |
Vasik Rajlich (Czech Republic) | 3126 (64-bit 4CPU) |
| Scorpio v2.7 | Daniel Shawul (Ethiopia) | 2851 (32-bit) |
| Slow Chess Blitz WV2.1 | Jonathan Kreuzer (US) | 2741 |
| Spark v1.0 | Allard Siemelink (Netherlands) | 3097 (64-bit 4CPU) |
| Spike v1.4 Leiden | Volker Böhm and Ralf Schäfer (Germany) | 3149 |
| Stockfish Stockfish (chess) Stockfish is an open source chess engine, developed by Tord Romstad, Joona Kiiski and Marco Costalba and licensed under the GNU General Public License version 3. The current version 2.1.1 is available as C++ source code, and also has precompiled versions for Microsoft Windows, Mac OS X Snow... v2.1.1 |
Tord Romstad (Norway), Marco Costalba (Italy) & Joona Kiiski (Finland) | 3259 (64-bit 4CPU) |
| TheMadPrune v1.1.25 | Fabien Letouzey (France), WH Lowery Jnr (USA) | 2978 (2CPU) |
| Thinker v5.4C Inert | Lance Perkins (Canada) | 3029 (64-bit) |
| Toga II v1.4.1SE | Derived from Fruit v2.1 by Fabien Letouzey (France), Thomas Gaksch (Germany) | 3007 (4CPU) |
| Tornado v4.4 | Engin Ustun (Germany) | 2840 (32-bit) |
| Twisted Logic 20100131x | Edsel Apostol (Philippines) | 2874 (64-bit) |
| Umko v1.0 | Borko Boskovic (Slovenia) | 2906 (32-bit) |
| Wildcat v8 | Igor Korshunov (Belarus) | 2731 |
| Zappa v1.1 (latest free version) |
Anthony Cozzie (US) | 2712 (64-bit) |
Pedagogical
These open sourceOpen source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
chess programs were expressly written to teach the craft of chess programming.
- GNU ChessGNU ChessGNU Chess is a computer program which plays a full game of chess against a human or other computer program.GNU Chess is one of the oldest computer chess programs for Unix-based computers and one of the earliest available with full source code....
The goal of GNU Chess is to serve as a basis for research. - ChessBin.com C# Chess Engine.
- Chess Program in C#.
- FirstChess (in C).
- Gerbil
- Gray Matter (in C++).
- MSCP (in C)
- MizarMizar chess engineMizar is a chess engine developed by Nicola Rizzuti. Mizar is distributed with its source code for the use of programmers who may wish to understand how a chess program works...
(in C). - Viper (in C++).
- Xadreco Chess Engine (in C).
- ChEngine (in C#).
- Stockfish (in C++).
There is also source-available proprietary software.
- TSCPTom Kerrigan's Simple Chess ProgramTom Kerrigan's Simple Chess Program is a chess program by Tom Kerrigan. Its main goal is to demonstrate how a chess program works. The source code is available and heavily commented to make learning simple...
(in C).
These small programs are written for hobby or to win programming contests, currently able to play all legal chess moves although with limited text interface.
- Micro-Max (chess engine), by H.G.Muller, a 133-line chess program in C (1433 characters)
- Toledo NanochessToledo NanochessToledo Nanochess is a chess engine developed by Mexican Oscar Toledo Gutiérrez, a four times winner of the IOCCC. According to IOCCC rules it is 1255 characters...
, by Óscar Toledo G., an obfuscated chess program written in 1326 bytes of C.
Commercial
These chess programs are sold commercially. Most of these also include their own user interface.- Chess Genius, by Richard Lang of MephistoMephisto (chess computer)Mephisto was a line of chess computers sold by Hegener & Glaser '. In addition to integrated travel and sensory computers, they also sold a line of modular electronic autosensory boards which could accept different program, processor, and display modules.Its strongest software was written by...
fame - ChessmasterChessmasterChessmaster is a chess playing computer game series which is now owned and developed by Ubisoft. It is the best-selling chess franchise in history, with more than five million units sold .-Timeline:...
- Chess TigerChess TigerChess Tiger is a strong chess program developed by Christophe Théron.A shareware version of Chess Tiger was also made for the Palm OS. It is known for its high level of strength and a trainer engine to help beginners improve their chess techniques....
- FritzFritz (chess)Fritz is a German chess program developed by Frans Morsch and Mathias Feist and published by ChessBase. There is also a version called Deep Fritz that is designed for multiprocessing....
(single processor), Deep Fritz (multi processor) - Gandalf
- HIARCS
- JuniorJunior (chess)Junior is a computer chess program authored by the Israeli programmers Amir Ban and Shay Bushinsky. Grandmaster Boris Alterman assisted, in particular with the opening book...
- (single- and multi-processor versions) - The King - the engine of the commercial ChessmasterChessmasterChessmaster is a chess playing computer game series which is now owned and developed by Ubisoft. It is the best-selling chess franchise in history, with more than five million units sold .-Timeline:...
program - Ktulu
- Loop (also the engine for Wii ChessWii ChessWii Chess is a chess video game for the Wii console. It was developed by Nintendo and was released on January 18, 2008 in Europe as a budget-priced retail title. Under the name , it was released as a downloadable WiiWare title in Japan on September 30, 2008...
) - NaumNaum (chess)Naum is a computer chess engine by Aleksandar Naumov . The current version 4.2 was released in March 2010. The commercial distribution is "engine only" on the website of the programmer. The program supports both UCI and Winboard and can therefore be operated under different graphical interfaces...
versions 2.1 and later - Onno
- RebelREBEL (chess)REBEL was a world champion chess program developed by Ed Schröder. Development of REBEL started in 1980 on a TRS-80, and it was ported many times to dedicated hardware and the fastest microprocessors of the day:...
- (see also ProDeo) - Ruffian 2
- RybkaRybkaRybka is a computer chess engine designed by International Master Vasik Rajlich. , Rybka is one of the top-rated engines on chess engine rating lists and has won many computer chess tournaments...
- ShredderShredder (chess)Shredder is a commercial chess program developed in Germany by Stefan Meyer-Kahlen in 1993. Shredder won the World Microcomputer Chess Championship in 1996 and 2000, the World Computer Chess Championship in 1999 and 2003, the World Computer Speed Chess Championship in 2002, 2003, 2004, 2005, and...
- Deep Sjeng
- SmarthinkSmarThinkSmarThink is a computer chess engine written by Sergei S. Markoff of Russia. This engine became a Russian computer chess champion in 2004 and CIS computer chess champion in 2005....
- SparkChessSparkChessSparkChess is a successful commercial chess program designed by Armand Niculescu for Media Division srl. It is written entirely in Actionscript...
- Zappa
Private
| Name | Author | Country |
|---|---|---|
| ApiChess | Max Himam | France |
| Azraël | Christopher Conkie | United Kingdom |
| Carnivor | Michael Sherwin | USA |
| Cheetah | Ralf Schäfer | Germany |
| Chepla | Mikael Bäckman | Sweden |
| Chimp | Andy Duplain | United Kingdom |
| Chiron | Ubaldo Andrea Farina | Italy |
| Cipollino | Giancarlo delli Colli | Italy |
| Cogito | Joerg Schaefer | Germany |
| Cowrie Chess | Chan Rasjid | Singapore |
| Czolgista | Tomasz Kazimierski | Poland |
| Diep | Vincent Diepeveen | The Netherlands |
| Dr. Theopolis | Corby Nichols | USA |
| EdlChess | Stephan Edlich | Germany |
| EGM | Pawel Kobylarz | Poland |
| Eichhörnchen | Wieland Belka | Germany |
| Ferret past winner of the World Computer Speed Chess Championship World Computer Speed Chess Championship World Computer Speed Chess Championship is an annual event where computer chess engines compete against each other at blitz chess time controls. It is held in conjunction with the World Computer Chess Championship... |
Bruce Moreland | USA |
| Flywheel | Don Cross | USA |
| Freccia | Stefano Gemma | Italy |
| Grok | Peter Kappler | USA |
| HansDamf | Gerd Isenberg | Germany |
| Hector for Chess | Csaba Jergler | Hungary |
| Ikarus Ikarus (chess) Ikarus was the Computer Speed Chess Champion in 2006. It did so by defeating the four-time champion Shredder in the World Computer Speed Chess Championship which took place on May 29, 2006 in Turin.... past winner of the World Computer Speed Chess Championship World Computer Speed Chess Championship World Computer Speed Chess Championship is an annual event where computer chess engines compete against each other at blitz chess time controls. It is held in conjunction with the World Computer Chess Championship... |
||
| Kallisto | Bart Weststrate | Netherlands |
| LearningLemming | Sam Hamilton | USA |
| MeneChess | Shaun Howe | United Kingdom |
| Moneypenny | Matt Shoemaker | USA |
| NaltaP312 | Yves Catineau | France |
| Nightmare | Joost Buijs | Netherlands |
| Now | Mark Lefler | USA |
| Nullmover | Michael Langeveld | Netherlands |
| Olympus | Joshua Shriver | USA |
| Pandix | Gyula Horváth | Hungary |
| Pebble | Adam Goodwin | USA |
| Philidor | Christian Barreteau and Bruno Lucas | France |
| Purple Haze | Vincent Ollivier | France |
| Sibyl | Milikas Anastasios | Greece |
| Sillycon | Lasse Hansen | Norway |
| Spandrel | Robert Purves | New Zealand |
| Symbolic | Steven Edwards | USA |
| Telepath | Charles Roberson | USA |
| Tinker | Brian Richardson | USA |
| TwilightChess | Tony Paletta | France |
| Tzunami | Ivo Tops | Netherlands |
| Vlad Tepes | Henk Fennema | Netherlands |
| WaDuuttie | Maarten Claessens | Netherlands |
| Waster | Geoff Westwood | United Kingdom |
| Weid | Jaap Weidemann | South Africa |
| XiniX | Tony van Roon-Werten | Netherlands |
| Z | Manuel Díaz | Spain |
| Zeta | Srdja Matovic | Montenegro |
| Ziggurat | David Norris | United States |
| Zilch | Mike Leany | USA |
Dedicated hardware
These chess playing systems include custom hardware or run on supercomputerSupercomputer
A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...
s. All are historical; chess supercomputers have not competed in computer tournaments since Hydra played in 2006.
- Bebe, a strong bit-slice processor in the 1980s
- BelleBelle (chess machine)Belle was the name of a chess computer and its associated software, developed by Joe Condon and Ken Thompson at Bell Labs in the 1970s and 1980s. Belle was the first computer built for the sole purpose of chess playing. The strongest computer chess system of its time, Belle achieved a USCF rating...
- Chess (Northwestern University)Chess (Northwestern University)Chess was a pioneering chess program from the 1970s, authored by Larry Atkin and David Slate at Northwestern University. Chess ran on Control Data Corporation's line of supercomputers. It dominated the first computer chess tournaments, such as the World Computer Chess Championship and ACM's North...
- ChipTestChipTestChipTest was a 1985 chess playing computer built by Feng-hsiung Hsu, Thomas Anantharaman and Murray Campbell at Carnegie Mellon University. It is the predecessor of Deep Thought which in turn evolved into Deep Blue....
- Cray BlitzCray BlitzCray Blitz was a computer chess program written by Robert Hyatt, Harry Nelson, and Albert Gower to run on the Cray supercomputer. It was derived from "Blitz" a program that Hyatt started to work on as an undergraduate. "Blitz" played its first move in the fall of 1968, and was developed...
- Deep Blue
- Deep ThoughtDeep Thought (chess computer)Deep Thought was a computer designed to play chess. Deep Thought was initially developed at Carnegie Mellon University and later at IBM. It was second in the line of chess computers developed by Feng-hsiung Hsu, starting with ChipTest and culminating in Deep Blue...
- HiTechHiTechHiTech was a chess machine built at Carnegie Mellon University under the direction of World Correspondence Chess Champion Dr. Hans J. Berliner, by Berliner, Carl Ebeling, Murray Campbell, and Gordon Goetsch....
- HydraHydra (chess)Hydra was a chess machine, designed by a team with Dr. Christian "Chrilly" Donninger, Dr. Ulf Lorenz, GM Christopher Lutz and Muhammad Nasir Ali. Since 2006 the development team consised only of Donninger and Lutz. Hydra was under the patronage of the PAL Group and Sheikh Tahnoon Bin Zayed Al...
, predecessor was called Brutus
Commercial dedicated computers
In the 1980s and early 1990s, there was a competitive market for strong dedicated chess computers. Many form-factors were sold, from handheld peg-board computers to wooden auto-sensory boards with state-of-the-art processors. This market changed in the mid-90s when the economical embedded processors in dedicated chess computers could no longer compete with the fast processors in personal computers. Nowadays, most dedicated units sold are of beginner and intermediate strength.- Chess Challenger, a line of chess computers sold by Fidelity Electronics from 1977 http://www.ismenio.com/chess_cc1.html to 1992. These models won the first four World Microcomputer Chess Championships.
- ChessMachineChessmachineThe ChessMachine was a chess computer sold between 1991 and 1995 by TASC . It was unique at the time for incorporating both an ARM2 coprocessor for the chess engine on an ISA card which plugged into a IBM PC and a software interface running on the PC to display a chess board and control the engine...
, an ARMARM architectureARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
-based dedicated computer, which could run two engines:- The KingThe King- In gaming :* King Harkinian, a character in The Legend of Zelda video game series* The King, the chess engine in the computer game Chessmaster...
, which later became the ChessmasterChessmasterChessmaster is a chess playing computer game series which is now owned and developed by Ubisoft. It is the best-selling chess franchise in history, with more than five million units sold .-Timeline:...
engine, was also used in the TASC R30 dedicated computer - Gideon, a version of RebelREBEL (chess)REBEL was a world champion chess program developed by Ed Schröder. Development of REBEL started in 1980 on a TRS-80, and it was ported many times to dedicated hardware and the fastest microprocessors of the day:...
, in 1992 became the first microcomputer to win the World Computer Chess ChampionshipWorld Computer Chess ChampionshipWorld Computer Chess Championship is an annual event where computer chess engines compete against each other. The event is organized by the International Computer Games Association...
- The King
- MephistoMephisto (chess computer)Mephisto was a line of chess computers sold by Hegener & Glaser '. In addition to integrated travel and sensory computers, they also sold a line of modular electronic autosensory boards which could accept different program, processor, and display modules.Its strongest software was written by...
, a line of chess computers sold by Hegener & Glaser. The units programmed by Richard Lang won six consecutive World Microcomputer Chess Championships. They bought out Fidelity in 1989. - Novag sells a line of tactically strong computers, including the Constellation, Sapphire, and Star Diamond brands.
- SaitekSaitekSaitek is a designer and manufacturer of consumer electronics founded in 1979 by Swiss technologist Eric Winkler. They are best known for their PC gaming controllers, mice, keyboards especially the Eclipse series of back-lit keyboards, and their Flight Yoke System.- History :Saitek was founded in...
sells mid-range units of intermediate strength. They bought out Hegener & Glaser and its Mephisto brand in 1994. - Excalibur Electronics sells a line of intermediate strength units. Excalibur was started in 1992 by the son of the founder of Fidelity Electronics.
- Phoenix Chess Systems makes limited edition units based around StrongARMStrongARMThe StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
and XScaleXScaleThe XScale, a microprocessor core, is Intel's and Marvell's implementation of the ARMv5 architecture, and consists of several distinct families: IXP, IXC, IOP, PXA and CE . Intel sold the PXA family to Marvell Technology Group in June 2006....
processors running modern engines and emulating classic engines
Historical
These chess programs run on obsolete hardware.- 1K ZX Chess1K ZX Chess1K ZX Chess is a chess-playing computer program for the unexpanded Sinclair ZX81, created by programmer David Horne. The game implements most chess rules , artificial intelligence, and a user interface...
- Colossus ChessColossus ChessColossus Chess is a series of chess-playing computer programs developed by Martin Bryant, commercially available for various home computers in the 1980s.- Colossus Chess :...
- KaissaKaissaKaissa was a chess program developed in the Soviet Union in the 1960s. It was named so after the chess goddess Caissa. Kaissa became the first world computer chess champion in 1974 in Stockholm.- History :...
- Kotok-McCarthyKotok-McCarthyKotok-McCarthy also known as was the first computer program to play chess convincingly. It is also remembered because it played in and lost the first chess match between two computer programs.-Development:...
- Mac Hack
- MicrochessMicrochessMicrochess, by Peter R. Jennings, was originally a microcomputer chess program for the MOS Technology KIM-1 microcomputer, first released on December 18, 1976...
was the first commercial game for a personal computer, developed first for the KIM-1KIM-1The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976...
and later Commodore PETCommodore PETThe Commodore PET was a home/personal computer produced from 1977 by Commodore International...
, Apple IIApple IIThe Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...
, TRS-80TRS-80TRS-80 was Tandy Corporation's desktop microcomputer model line, sold through Tandy's Radio Shack stores in the late 1970s and early 1980s. The first units, ordered unseen, were delivered in November 1977, and rolled out to the stores the third week of December. The line won popularity with...
and others. Bobby Fischer played against MicroChess. http://www.benlo.com/microchess/microchess.html - SargonSargon (chess)Sargon is a line of chess-playing software for personal computers.-Origin:The original SARGON was written by Dan and Kathleen 'Kathe' Spracklen in a Z80-based computer called Wavemate Jupiter III...
- Socrates IISocrates IISocrates II is a chess program that, in 1993, won the 23rd North American Computer Chess Championship. It ran on an IBM PC. This was the first and only time that a stock microcomputer won this event, finishing ahead of past winners Cray Blitz and HiTech....
See also
- List of chess software
- Chess Engines Grand Tournament
- Computer chessComputer chessComputer chess is computer architecture encompassing hardware and software capable of playing chess autonomously without human guidance. Computer chess acts as solo entertainment , as aids to chess analysis, for computer chess competitions, and as research to provide insights into human...
- Internet chess serverInternet chess serverAn Internet chess server is an external server that provides the facility to play, discuss, and view the board game of chess over the Internet...
- Chess Engine Communication ProtocolChess Engine Communication ProtocolThe Chess Engine Communication Protocol is an open communication protocol that enables a chess engine to communicate with its user interface....
- Universal Chess InterfaceUniversal Chess InterfaceThe Universal Chess Interface is an open communication protocol that enables a chess program's engine to communicate with its user interface....
External links
- Chess Engine's Polyglot Opening Book for WinBoard GUI. - A general (learning) purpose Chess Engine's Polyglot Opening Book for WinBoard GUI.