Google’s Go-playing machine has scored a second victory against the best human player.
Go champion Lee Sedol said he was left “speechless” after his second straight loss to the machine in a highly anticipated human versus machine face-off.
Mr Lee, one of the best Go players in the world with 18 world championships, was grim and ashen after the game, which lasted more than four hours.
“I’m quite speechless,” he said at a press conference. “It was a clear loss on my part. From the beginning there was no moment I thought I was leading.”
The latest victory by AlphaGo over the South Korean puts Google’s AlphaGo team one victory away from claiming the one million US dollars (€910,995) prize.
If AlphaGo wins, the prize money is to be donated to Unicef, Go organisations and charities.
AlphaGo’s first win against Mr Lee, on Wednesday, shook the Go-playing world, marking a milestone in the development of artificial intelligence.
Hundreds of thousands of South Koreans, even those who do not play the popular board game, followed the games on live TV and on YouTube. All major local newspapers reported Mr Lee's loss on their front pages.
"Two-year-old artificial intelligence masters 5,000-year-old human Go," said a headline in the Chosun Ilbo, South Korea's most circulated daily newspaper.
Many had believed it would take another decade for computers to conquer the ancient Chinese board game, one of the most creative games ever devised and the only board game left to conquer after chess was mastered by computers in 1997. Go is much more complex than chess.
Google’s team compared AlphaGo’s win to landing on the moon.
The three remaining games run until Tuesday. Even if Mr Lee loses the third game, he will play all five games.
Mr Lee (33) brimmed with confidence two weeks ago but that confidence was missing after two straight defeats.
“The third game is not going to be easy for me,” he said.