Human Go champion scores first win over computer

SEOUL, South Korea – A champion Go player scored his first win over a Go-playing computer program on Sunday after losing three straight times in the ancient Chinese board game, saying he finally found weaknesses in the software.

Lee Sedol’s victory over AlphaGo is a reminder that Google’s Go-playing program has room for improvement despite winning the first three matches in the best-of-five series and the $1 million prize, which will be donated to charity.

Lee had said earlier in the series that he was unable to beat AlphaGo because he could not find any weaknesses in the software’s strategy.

But after Sunday’s match, the 33-year-old South Korean Go grandmaster said he found two weaknesses in the artificial intelligence program. Lee said that when he made an unexpected move, AlphaGo responded with a move as if the program had a bug, indicating that the machine lacked the ability to deal with surprises.

AlphaGo also had more difficulty when it played with a black stone, according to Lee.

For the final match of the series, scheduled for Tuesday, Lee has offered to play with a black stone, saying it would make a victory more meaningful.