the verge: AlphaGo is now 3-1 up in the series with a professional record, if you can call it that, of 9-1 including the 5-0 win against European champion Fan Hui last year. by Sam Byford
'Lee's first win came after an engrossing game where AlphaGo played some baffling moves, prompting commentators to wonder whether they were mistakes or — as we've often seen this week — just unusual strategies that would come good in the end despite the inscrutable approach.
'According to tweets from DeepMind founder Demis Hassabis, however, this time AlphaGo really did make mistakes. The AI "thought it was doing well, but got confused on move 87," Hassabis said, later clarifying that it made a mistake on move 79 but only realized its error by 87. AlphaGo adjusts its playing style based on its evaluation of how the game is progressing.
'Lee entered the post-game press conference to rapturous applause, remarking "I've never been congratulated so much just because I won one game!" Lee referred back to his post-match prediction that he would win the series 5-0 or 4-1, saying that this one win feels even more valuable after losing the first three games.
'"Lee Se-dol is an incredible player and he was too strong for AlphaGo today," said Hassabis, adding that the defeat would help DeepMind test the limits of its AI. "For us this loss is very valuable. We're not sure what happened yet."'