Claudia is an UCI chess engine written in C, with the purpose of serving as an exercise in chess programming techniques.

It now plays on the Free Internet Chess Server (FICS) under the handle Claudiae.

USAGE

Claudia runs as a console application and can be used with any chess GUI that supports the UCI protocol. It is known to compile with gcc (both 64 and 32 bits systems) and Visual C++, has been thoroughly tested with Arena, and should be fairly stable right now.


ALGORITHM

The engine uses:

	* 0x88 internal board representation,
	* bitboards for pawn structure evaluation;
	* a single threaded negamax algorithm
	* alpha-beta pruning,
	* iterative deepening,
	* aspiration windows,
	* principal variation search,
	* null move pruning,
	* lazy evaluation,
	* quiescent search,
	* check extensions,
	* static exchange evaluation,
	* killer moves heuristic
	* transposition tables,
	* pondering.

Its leaf evaluation function is still very rudimentary; currently it takes into account material advantage, piece mobility and pawn structure, and uses a tapered evaluation with limited ending knowledge.

Claudia supports opening books in Polyglot (.bin) format, and will attempt to use an opening book named "book.bin" and placed in its same directory. The default book has been built from over forty thousand high-quality tournament games played by Grand Masters and International Masters over the last five years.


NAME

Claudia is obviously named after Claude E. Shannon (1916 - 2001).


COPYRIGHT

This program has been written from scratch by Antonio Garro, and is released under a permissive BSD license: the code can be used and modified, as long as proper attribution is maintained. Please refer to the license in the source code for further details.

The Polyglot opening book support uses code written by Michel Van den Bergh and released by such author into the public domain.

The Mersenne Twister pseudorandom number generator was written by Makoto Matsumoto and Takuji Nishimura. See copyright notice in random.h