Later that year it won again the Dutch open computer chess championship, scoring 8/9.
In October 2008, Rybka won the 16th World Computer Chess Championship, held in Beijing, China, scoring 8/9.
GM Jaan Ehlvest was again chosen to play Rybka, getting twice the thinking time and white every match, with Rybka having only a three-move opening book, limited (512MB) hash size, and no endgame tablebases (the match being dubbed "Everything but a pawn").
The match ended 4.5–1.5 after three Rybka wins and three draws.
Vasik Rajlich started working on his chess program at the beginning of 2003.
The first Rybka beta was released on December 2, 2005.
" He replied, "As for the name Rybka – I am sorry but this will remain my private secret." The details of the evaluation function are unknown, but since version 2.3.1 it has included work by GM Larry Kaufman on material imbalances, much of which was worked out in a series of papers in the 1990s.
Several members of the Rybka team are strong chess players: Vasik Rajlich, the main author of Rybka is an International Master (IM).
Iweta Rajlich, Vasik Rajlich's wife and the main Rybka tester is a Women's GM (WGM) and IM.In September 2008, Rybka played an odds match against Vadim Milov, its strongest opponent yet in an odds match.Milov at the time had an Elo rating of 2705, ranking him 28th in the world.in Czech, means little fish in Czech, Polish, and in many other Slavic languages.Vasik Rajlich was once asked in an interview by Alexander Schmidt, "Did you choose the name Rybka because your program always slipped out of your hands like a little fish?In the April 2006 PAL/CSS Freestyle main tournament, an unaided Rybka 1.1 took first place.