According to the makers of this disc rybka 23 is the strongest playing program in the world developed by international master vasik rajlich hungary to provide you with a game that comes as close as it can to playing with a real chess master rybka 23 uci chess openings 2007 is a unique program including many opportunies for playing and infinite analysis of games there are 31 million games in ca and pgn formats and the disc includes expert annotations and explanations languages engl