Go is a game that computers have trouble with traditionally. Played on a board with a grid of either nine by nine or 19 by 19 lines, the game pits two players against each other in an attempt to control territory using black and white stones. The player holding the black stones goes first, placing a stone at an intersection of two lines on the grid. The player holding the white stones goes next. The two players attempt to control territory on the board by surrounding their opponents stones with their own.
The game is tough for computers to play. Unlike games like chess and checkers, Go gets more complicated the longer the game lasts. In chess and checkers, you remove pieces during play as they're captured. In Go, you're placing more stones on the board until you move into an endgame. For this and other reasons, computer programs have had trouble keeping up with human players.
But in July 2010, the MoGoTW program running on 512 cores of the Cray XT4/XT5 supercomputer defeated professional Go player Catalin Taranu in a 19 by 19 Go match. The computer had a seven-stone handicap and won by just 1.5 points.
While Taranu's loss may mark a new era in computer dominance in gaming, it might be premature to dismiss humans. We're clever creatures -- we're not ready to say "game over" just yet.