South Korea’s Lee Sedol, the world’s top go player, defeated Google’s artificial intelligence system AlphaGo on Sunday for the first time, in the fourth match of a five-game series.
The 33-year-old grandmaster, effectively representing humankind, defeated AlphaGo a day after the go-playing AI system, developed by London-based Google DeepMind, picked up its third straight win to claim overall match victory in the best-of-five series being held at a Seoul hotel.
The final match will be held on Tuesday to determine the final match score.
Lee, who debuted as a professional player at age 12, is regarded as the best go player of the past decade, with 18 world titles under his belt.
AlphaGo last year won 5-0 in a formal match against the reigning European Champion Fan Hui to become the first program to ever beat a professional go player in an even game.
Go, which originated in China more than 2,500 years ago, is considered to be more complex than chess. According to Google, there are more possible positions than there are atoms in the universe.
Players take turns to place black or white stones on a board, trying to capture the opponent’s stones or surround empty space to make points of territory.