Crafty
Crafty is a free chess program by Robert Hyatt, an American computer scientist. It is able to win games against human grandmasters, especially in blitz chess. In November 2006, Crafty was performed on version 18:12 AMD Athlon 1.2 GHz, in the ranking of the SSDF rating with a number of 2616 at number 36.
It is continuously developed since 1994. His predecessor, Cray Blitz won the World Computer Chess Championships in 1983 and 1986. The code is portable, so Crafty runs on Linux and Microsoft Windows. The program uses the XBoard protocol and can be used with appropriate chess frontends. The current version is 23.4.
In the computer world championship 2004 Crafty occupied in Version 19:15 fourth place, level on points with Fritz 8, Junior 8 behind as a world champion and Shredder 8 A year later occupied Crafty fifth of twelve participating programs. It ran on an AMD Opteron system with four processors, and thus evaluated over 16 million positions per second.
The program plays almost continuously on the Internet Chess Club against people and other chess programs. The results are used to detect weaknesses and to improve the program continuously. In recent years, however, there was no significant increase in playing strength more. One speaks therefore of the Crafty threshold: chess programs, which are stronger than Crafty, belonging to at least one advanced class. Current development is focused on the parallelization.
The source code of Crafty is available, the use of the source code and the program but is limited by the license. Crafty is thus not free software and does not meet the open source definition. The source code is used by many programmers as a template for the implementation of basic functions, so it came even to allegations of plagiarism in computer chess tournaments.
Crafty is one of the programs that are included in the SPEC CPU benchmark test. It is also included as an additional chess engine Fritz and dominated in this version even the multivariate analysis mode.
Technical details
Crafty is written in ANSI C and assembler routines. There are optimized versions for different platforms.
Crafty uses a bitboard data structure for the field, numerous optimization techniques of the alpha-beta search, such as pruning, killer heuristic, Quiescent search and zero - train - search, and hash tables. In the final Crafty can use endgame databases. The software offers on many adjustable parameters configuration options by the user.