SEOUL • A Google-developed supercomputer stunned South Korean Go grandmaster by taking the first game of a five-match showdown between man and machine in Seoul yesterday.
After about 3½ hours of play, Mr Lee Se Dol , one of the greatest players of the ancient board game in the modern era, resigned when it became clear the AlphaGo computer had taken an unassailable lead.
"I was very surprised because I did not think I would lose the game," a clearly shocked Mr Lee told reporters.
"I think a mistake I made at the very beginning lasted until the very end," the 33-year-old added.
"And I didn't know AlphaGo would play the game in such a perfect manner."
Although the computer had defeated European champion Fan Hui 5-0 last October, it had been expected to struggle against Mr Lee, who has topped the world rankings for most of the past decade.
But its creators had been bullish going into the highly anticipated match at the Four Seasons hotel, saying the computer, which employs algorithms that allow it to learn and improve from match-play experience, was even stronger than when it took on Mr Fan.
Mr Demis Hassabis, chief executive of AlphaGo developer DeepMind, said: "We are very, very excited by this historic moment and very, very pleased with how AlphaGo performed."
The match sparked enough interest to warrant an Internet live-stream as well as live TV broadcasts in South Korea, China and Japan. Experts say the complexity of the game and incomputable number of move options mean that the computer must be capable of human-like "intuition" to prevail.
When Mr Lee first accepted the challenge, he had confidently predicted a clear-cut win, saying AlphaGo's performance against Mr Fan had been nowhere near good enough to defeat him.
Go involves two players alternately laying black and white stones on a checkerboard-like grid of 19 lines by 19 lines. The winner is the player who manages to seal off more territory. The match promises a US$1 million (S$1.39 million) payout for the winner.