The latest advances in computer go are covered in a new post by The New Yorker. In “The Electronic Holy War”, Patrick House reports on the Densei-sen, “or ‘electronic holy war,’ tournament, in Tokyo, where the best Go programs in the world play against one of the best humans” where Crazy Stone last March defeated Yoshio “the Computer” Ishida. 
The article does an excellent job of explaining why go has been so tough for computers to crack. “Part of the difficulty for computers—and humans—is that it is often hard to determine at any given time whether a group of pieces is being surrounded or doing the surrounding, and thus who is ahead…Without a clear understanding of who is ahead, programs like Deep Blue stutter. ‘All the machinery that was built up for computer chess is pretty useless,’” (Murray) Campbell (a member of the IBM Deep Blue team says.
It also explains how “Monte Carlo” algorithms, initially developed seventy years ago as part of the Manhattan Project, have been the key to developing stronger go programs. “The better the programs got, the less they resembled how humans play: during the game with Ishida, for example, Crazy Stone played through, from beginning to end, approximately three hundred and sixty million randomized games. At this pace, it takes Crazy Stone just a few days to play more Go games than humans collectively ever have. ‘I have to be honest: I still find it kind of magical, that it works as well as it does,’ Campbell said.”
The “electronic holy war” will run once a year in Tokyo until 2017, the report continues. “This past weekend, at the second annual tournament, Crazy Stone faced Norimoto Yoda, a Japanese professional who has a reputation for slamming pieces onto the board—sometimes shattering them—to intimidate his opponent. Crazy Stone was given a four-move head start and, lacking the eyes and ears through which another player might have been intimidated, won by two and a half points. “After the match, Yoda, through a translator, told me that he was grateful for Crazy Stone because it eased up at the end and allowed the game to be closer than it actually was: the result of randomness—or, perhaps, of the beginnings of pity.”
Photograph of Rémi Coulom and Ishida Yoshio courtesy of gogameguru.com
