While simple to explain and to learn, Go has subtle gradations of ability. There are hundreds of professionals, mainly in Japan, Korea and China, yet even the best computer version is only as good as an average European club player, who is as far from being professional as the average tennis club player is from playing at Wimbledon. Even the best Go-playing program is presently only ranked about 9kyu. Why are computers so bad at Go? First, playing Go plunges a computer into a sea of possibilities in which most drown. A chess board, with 64 squares, is comparatively tiny: each turn offers about 30 possible legal moves. In Go, with 361 points, few moves are illegal, offering more possibilities - on average, about 200 per turn. Thus the total number of possible moves in chess is between 1060 and 1070; in Go it is about 10250.-http://technology.guardian.co.uk/online/insideit/story/0,,1835570,00.html