In June 2011 it was widely reported in the global media that the International Computer Games Association (ICGA), headed by Dr. David Levy, had found chess programmer Vasik Rajlich in breach of the ICGA’s annual World Computer Chess Championship (WCCC) tournament rule related to program originality. In the ICGA’s accompanying report it was asserted that Rajlich’s chess program Rybka contained “plagiarized” code from Fruit, a program authored by Fabien Letouzey of France. Rajlich, who cruised to victory in four consecutive WCCC tournaments in 2007, 2008, 2009 and 2010, was retroactively stripped of all titles he had won in competition and was slapped with a lifetime ban. In response, Rajlich claimed complete innocence and made it clear that he found the ICGA’s investigatory process and conclusions to be biased and unprofessional, and the charges baseless and unworthy. He refused to be drawn into a protracted dispute with his accusers or mount a comprehensive defense.
On December 4, 2005 a free, downloadable chess program named Rybka 1.0 Beta was initially released and took a sizable lead on all then-existing chess program strength ranking lists, surpassing all commercial programs. Rybka then proceeded to rapidly widen its lead with subsequent versions. Rybka went on to become a commercial engine in 2006. Working with Grandmaster Larry Kaufman, one of the world’s leading position evaluation specialists, Rajlich issued the seminal Rybka 3 in 2008. Rybka 3 was over 100 Elo points stronger than Rybka 2, an enormous improvement in what was already the leading commercial program. The latest public edition of Rybka (Rybka 4.1) is more than 300 Elo points stronger than the top competitors that existed in late 2005 on comparable hardware.
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