The computer program, called AlphaGo, trounced Fan Hui, the reigning European Go champion, 5 games to 0 in a formal match played in October 2015, researchers report January 27 in Nature.
Go, a game that originated in China more than 2,500 years ago, is much more complicated than chess, with an order of magnitude more possible opening moves, study coauthor Demis Hassabis of Google DeepMind said at a news conference on January 26 in London. Many researchers thought a computer wouldn't be able to beat a top human player for another five or 10 years, he said.
AlphaGo learned to play Go in a humanlike manner: from experience. But the program needed much more practice than humans do to become an expert, Hassabis said: millions of games, rather than thousands.
In March, the program will put its skills to the ultimate test in a match against Lee Sedol, currently considered the best Go player in the world.