Maybe AlphaGo is fallible after all. Korean Go master Lee Sedol claimed victory over Google DeepMindās Go-bot on Sunday, his first in the five-game series.
It came too late to affect the outcome of the series ā AlphaGo clinched it on Saturday with its third straight win. But Leeās victory reversed the eventās sombre tone, inspiring the Go community, and the entire region.
After his win, Lee strolled into a press conference to unrestrained cheers from reporters, chants of āLEE-SE-DOLā. He acknowledged them almost shyly, with a slight bow, his eyes on the floor. But the grin on his face was a picture of relief.
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āIf I had lost one game, it would have hurt tremendously,ā he said. āBut because I lost three matches and got this single win, I wouldnāt exchange it for anything in the world.ā
The day before, he had lost to AlphaGoās most complete performance yet, falling behind early and never recovering.
āIt was so hard to watch,ā said Andrew Jackson of the . āHe just got steamrolled.ā
Astonishing play
In Sundayās game, Lee started conservatively, ceding the centre of the board. But on move 78, he turned the game around with an astonishing wedge play in the middle. Gu Li, one of Leeās rivals, commenting on the game in China, called it the āhand of godā, the kind of language that was being applied to AlphaGo in previous games.
AlphaGo responded to the unexpected move with a weak counter, which set off a brilliant sequence from Lee to capitalise. According to Demis Hassabis, one of DeepMindās founders, AlphaGo didnāt realise its mistake until eight moves later. āLee Sedol beat AlphaGo at its own game,ā said Jackson.
Watch the best human player take on the mighty AlphaGo AI at Go
Lee sat up straighter as he closed in on victory. The press room began to buzz as AlphaGo played increasingly bizarre moves, the death throes of an algorithm. Across the table from Lee, Aja Huang, the AlphaGo programmer who acts as its human avatar and places its stones on the board, appeared resigned. And then, a message appeared on his monitor: āThe result āwhiteresignā was added to the game information. AlphaGo resigns.ā
Lonely fight
After the third match, with camera shutters clicking, Lee had apologised āfor not being able to satisfy a lot of peopleās expectationsā. More than one reporter later admitted to holding back tears. Lee stressed it was not humanityās defeat, but his alone. He said that the pressure had got to him, and that he felt ākind of powerlessā.
One of Leeās fellow pros, Lee Hyun-wook, paid tribute to his heart and spirit. āHe is fighting such a lonely fight, and a hard fight against this invisible opponent.ā
The next day was an emotional 180. Yet, in his moment of victory, if Lee cracked a smile, I didnāt see it. His focus was back on the board, replaying the game.
In Go, itās customary to go over the match with your opponent to share your thought process. But across from Lee, there was only Aja Huang, looking around, unable to explain any of AlphaGoās blunders. As he left his chair, Lee gave him barely a nod. In victory, just as in defeat, Lee Sedol was utterly alone.
Read more:Ā Does a machine beating a Go master mean human-like AI is close?
Read more:Ā āIām in shock!ā How an AI beat the worldās best human at Go
Read more:Ā Google AI program crushes Korean Go legend again in round two
