Rybka 4 is now available and can be directly ordered from ChessBase. It has won three world championships, and just this weekend came first in the super-strong ICT10 computer tournament in Holland. Rajlich has always claimed that Rybka is original - even when confronted with the findings of the report by the president of the ICGA. The chess engine Rybka has become the touchstone in computer chess. The panel unanimously agreed that newer versions of Rybka are based on - and worse, that the early beta versions were based on, another open-source chess engine. Unfortunately, Rybka’s source code has never been available, so reverse engineering and straight-up move-evaluation comparison was used to analyze the originality of Rajlich’s chess engine.

To come to this rather epic and libelous conclusion, the ICGA assembled a 34-person panel of programmers who have competed in past championships to analyze Rybka. Curiously, ICGA isn’t even disqualifying Rybka because it copies Fruit - rather, it’s simply upset that Rajlich claims his engine is original, and refuses to give credit where it’s due. Rybka debuted the year after, and from the get-go experts were claiming that Rybka evaluated moves in an identical fashion to Fruit. This article is party based on my four part ChessBase article, but includes some new analysis.The ICGA’s entire case seems to hinge on, an open source chess engine that was the runner-up at WCCC 2005. The main conclusion is that the view computer experts take on this question is colored by two different views of software development, one that fits programming in an academic environment, one that fits programming in an industry environment. The question relates to practices for software development, legal issues like copyright law and touches on innovation and market leadership.ĭrawing on this array of topics we review the question if and to what extent Rybka was a clone/derivative. Since the actual source code was not available the determination of whether or not the program was original is complex and involves technical topics such as reverse engineering, program analysis, the abstraction–filtration–comparison test and black box testing such as ponder-hit analysis. The question of whether Rybka was substantially or slightly copied from other sources, or a completely original work, is still passionately being debated on forums and blogs. Rybka was, from its initial public release in 2005 until it was surpassed in 2010, by far the strongest chess engine ever seen. In this article I will consider the controversial Rybka case, which created a considerable stir in the computer chess community in 2011.

Rybka 5 chess engine