CrazyStone

Crazy Stone is a strong program by Rémi Coulom which uses Monte Carlo Tree Search and pattern learning. Crazy Stone came second in the 2007 Computer Olympiad behind MoGo. MoGo claims they were partly inspired by Crazy Stone (they are both French).

In July 2007, a match was played on KGS between Crazy Stone and KCC Igo, which Crazy Stone won 15-4. KCC Igo was considered the strongest commercial Go program at the time.

In spring of 2011, Crazy Stone, playing as ' bonobot', briefly reached 5 dan on KGS, and maintained a 4 dan rating.

On December 2nd, 2007, Crazy Stone won both of the KGS tournaments and the UEC Cup in Japan, ahead of MoGo in all three events. In 2008, Crazy Stone defended its UEC Cup title, defeating Many Faces of Go. Afterwards, it defeated Kaori Aoba, Japanese 4p, in a 7-stone handicap exhibition game. That gave Crazy Stone a claim to being the strongest program in the world at that time.

In March 2014, Crazy Stone established a 6-dan rating on KGS.

• Crazy Stone home page.
• AI Invades Go Territory article in Wired magazine dated 19 September 2006.
• The Mystery of Go, the Ancient Game That Computers Still Can't Win article in Wired magazine dated 13 May 2014.

Crazy Stone was mentioned in the French public radio show Science Publique: L'ordinateur deviendra-t-il un maître de Go ? (Will the computer become a Go master?) at France Culture on 2008-01-11 ( the old webpage of that podcast, archived in 2008).

An interview with Remi Coulom | Russian Go Federation (June 2011)

On March 20, 2013, Crazy Stone won a 19x19 four-stone handicap game against Honorary Honinbo Ishida Yoshio with a final score of B+2.5. ( Report and Game Record).

In 2016, a new version that uses deep learning was able to significantly increase Crazy Stone's strength.

Products powered by Crazy Stone

Windows:
Crazy Stone Deep Learning -The First Edition- on Steam
最強の囲碁Zero

Android and iOS:
CrazyStone DeepLearning Pro
CrazyStone DeepLearning
Champion Go ( correct Android link)

Engine Server

The smartphone/iPad versions offer in-app purchases of tickets to play against the CrazyStone Engine Server which is significantly stronger than native app version.

The engine server version offers 10 levels of play. Currently, there are no details publicly available regarding the strength of the server version or the hardware on which it runs. However, according to some user feedback, it seems to be significantly weaker than KGS 6d as of 24 April 2016.

The in-app description explains:

"Crazy Stone is a popularly known Go engine, based on the Monte-Carlo evaluation technique, combined with tree search, and has achieved 6d at KGS rating. We have optimized this version for Engine Server games."

Some users claim that the engine server version has been "optimized" to play faster but weaker, and estimate it to play at around 1-3d KGS level.