RDChess: RDChess playing strength

About RDChess

Update: I have stopped the development of RDChess. The RDChess.exe file still runs under Windows 10, but I have not updated the installation process. This blog is kept online for historical reasons only!

One of my main interests in leisure time has been programming chess. Beside my job and my family I have written the chess program RDChess, spending many evening and weekend hours for this hobby. In the mean time I have stepped down development of RDChess. Anyway the current last version V3.23 works still under Windows 7 and is still freeware :-). You may try RDChess yourself and download a free copy. Or look at the RDChess User Manual (english) oder in die RDChess Bedienungsanleitung (deutsch).

Read a Technical Description of the RDChess program, describing shortly the architecture, data structures, search and evaluation routines of the program. Mostly the program follows the "main stream" architecture of brute force programs of the Northwestern University program CHESS 4.5 type, but has a few "proprietary" program technical features. RDChess is comparably in strength to other freeware programs like "GNUCHESS for Windows". I am not a good chess player and lose practically every time against my own program. Anyway RDChess loses regulary against commercially sold chess programs like Fritz. Read further about the strength of the program and how to test it.

If you are a chess programmer, interested in how RDChess works in detail, look into the source code. Remark: The source code (Borland Delphi, x86 assembler) is well commented but contains comments in a mixture of German and English language, so be aware you may not understand the source not knowing the German language.

Wednesday, January 13, 2010

RDChess playing strength

The strength of RDChess has been evaluated by

playing against humans. RDChess usually wins, except you are a very professional chess player.
playing at Leo Dijksman's chess computer test site WBEC Ridderkerk Tournaments
playing against other computer chess programs in Olivier Deville's Chesswar Tournaments
playing at Guenther Simon's Regensburger WinBoard Cicuit RWBC
and many other chess test sites. Look at and search for rdchess in WinBoard Forum.
RDChess played as computer at the American Free Internet Chess Server FICS. After playing 531 games RDChess had a Blitz score of 2175 and a computer rank of 73.
with RDChess playing against test suites (see below).

If anybody runs test games against RDChess, I would be pleased to receive any kind of feedback as posting to this site or to my e-Mail adress.

RDChess test suites
There are a few test suites (Bratko-Kopec, Fine, Louguet II, WinAtChess, etc ; annotated with EPD best move tags ) stored for download here on this site.
RDChess has a built in automatic test procedure, which is started with the menu Game-> Run Test suite ...
In the file dialog you select a game library in .pgn format. In the PGN FEN setup string of each game in the library there has to be set an Extended Position Description (EPD) tag "bm" (best moves out from the start position). RDChess plays one move for each position and compares the calculated (searched) move with the stored best move from the "bm" - tag.
If the moves are identical, a hit counter is incremented. At the end of the test run a statistic with the number of test games, number of hits, used time, accumulated total node count etc. is displayed and may be printed: