Editing Crafty

{{for|the publisher of role-playing games|Crafty Games}}
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{{Infobox software
|name                       = Crafty
|logo                       =
|screenshot                 = Gnuchess vs crafty.png
|caption                    = Crafty (black) versus GnuChess (white)
|collapsible                =
|author                     = [[Robert Hyatt]], Michael Byrne, Tracy Riegle, Peter Skinner
|developer                  =
|released                   = <!-- {{Start date|YYYY|MM|DD}} -->
|discontinued               =
|latest release version     = 25.2<ref>{{cite web | url=http://www.craftychess.com/ | title=Crafty Chess | work=craftychess.com | accessdate=2014-10-07 | archive-url=https://web.archive.org/web/20190203055228/http://craftychess.com/ | archive-date=2019-02-03 | url-status=dead }}</ref>
|latest release date        = {{Start date and age|2016|10|29}}
|latest preview version     =
|latest preview date        = <!-- {{Start date and age|YYYY|MM|DD}} -->
|programming language       =
|operating system           =
|platform                   =
|size                       =
|language                   =
|status                     =
|genre                      = [[Chess program]]
|license                    = [[Proprietary software|Proprietary]], [[Freeware]]
|website                    = {{URL|www.craftychess.com}}
}}
'''Crafty''' is a [[chess program]] written by [[University of Alabama at Birmingham|UAB]] professor [[Robert Hyatt]], with development and assistance from Michael Byrne, Tracy Riegle, and Peter Skinner.<ref>{{cite web | url=http://fossies.org/linux/privat/crafty-25.0.1.zip:a/main.c | title=Crafty license with full author list | year=2010 | accessdate=2013-04-21 | url-status=dead | archiveurl=https://web.archive.org/web/20160603010901/http://fossies.org/linux/privat/crafty-25.0.1.zip%3Aa/main.c | archivedate=2016-06-03 }}</ref> It is derived from [[Cray Blitz]], winner of the 1983 and 1986 [[World Computer Chess Championships]]. Tord Romstad, co-author of [[Stockfish (chess)|Stockfish]], described Crafty as "arguably the most important and influential chess program ever".<ref>{{cite web | url=http://www.schach-welt.de/interviews/romstad-kiiski-costalba-engl | title=Interview with Tord Romstad (Norway), Joona Kiiski (Finland) and Marco Costalba (Italy) Programmers of Stockfish | date=28 March 2010 | work=Schachwelt | author=Frank Quisinsky | accessdate=14 April 2014 | url-status=dead | archiveurl=https://web.archive.org/web/20140217105444/http://www.schach-welt.de/interviews/romstad-kiiski-costalba-engl | archivedate=17 February 2014 }}</ref>
{{Chess programming series}}
Crafty finished in second place in the 2010 Fifth Annual ACCA Americas' Computer Chess Championships.  Crafty lost only one game, to the first-place winner, Thinker.{{cn|date=August 2024}}

Crafty also finished in second place in the 2010 World Computer Rapid Chess Championships.  Crafty won seven out of nine games, finishing behind the first-place winner Rybka by ½ point.{{cn|date=August 2024}}

In the World Computer Chess Championships 2004, running on slightly faster hardware than all other programs, Crafty took fourth place with the same number of points as the third-place finisher, [[Fritz (chess)|Fritz 8]]. On the November 2007 [[Swedish Chess Computer Association|SSDF]] ratings list, Crafty was 34th with an estimated [[Elo rating system|Elo rating]] of 2608.<ref>{{cite web | url=http://ssdf.bosjo.net/list.htm | title=The SSDF Rating List | publisher=[[Swedish Chess Computer Association]] | date=2007-11-03 | accessdate=2008-05-05}}</ref>

Crafty uses the [[Chess Engine Communication Protocol]] and can run under the chess interfaces [[XBoard]] and [[Winboard]].

Crafty is written in [[ANSI C]] with assembly language routines available on some CPUs, and is very portable. The source code is available, but the software is for "personal use" only and redistribution is only allowed under certain conditions.

Crafty pioneered the use of rotated [[bitboard]] data structures to represent the chess board, and was one of the first chess programs to support multiple processors.  It also includes [[negascout]] search, the [[Killer heuristic|killer move heuristic]], static [[Exchange (chess)|exchange]] evaluation, [[quiescence search]], [[alpha-beta pruning]], a [[transposition table]], a [[refutation table]], an evaluation cache, selective extensions, recursive null-move search, and many other features. Special editions of the program include enhanced features such as an [[Chess opening book (computers)|opening book]], positional learning, and an [[endgame tablebase]].

Crafty was one of the programs included in the [[Standard Performance Evaluation Corporation|SPEC CPU2000]] benchmark test.<ref>{{cite web | url=http://www.spec.org/cpu2000/CINT2000/186.crafty/docs/186.crafty.html | title=186.crafty: SPEC CPU2000 Benchmark Description | work=spec.org | publisher=[[Standard Performance Evaluation Corporation]] | accessdate=2010-05-11}}</ref> It is also included as an additional engine in [[Fritz (chess)|Fritz]].

==Graphical front-ends==
* [[GNOME Chess]]

==References==
{{reflist}}

==External links==
* [https://web.archive.org/web/20170724210936/http://www.craftychess.com/hyatt/hyatt.html Robert Hyatt's home page]


[[Category:Chess engines]]