Crazy Stone (Champion Go on iOS and Android platforms) is a Go playing engine, developed by Rémi Coulom, a French computer scientist.
[1] Coulom began writing Crazy Stone in July 2005, and at the outset incorporated the Monte Carlo algorithm in its design.
[2] Pattern recognition and searching was added in 2006, and later that year Crazy Stone took part in its first tournament, winning a gold medal in the 9×9 competition at the 11th Computer Olympiad.
[2] Coulom subsequently entered the program into the 12th Computer Olympiad the following year, winning bronze in the 9x9 and silver in the 19×19 competitions.
However, Crazy Stone's most significant accomplishment was to defeat Kaori Aoba, a professional Japanese 4 dan, in an 8-stone handicap match in 2008.