In the fourth game, international championship Go player Lee Sedol beats Google's AlphaGo. While Lee Sedol lost to AlphaGo in the previous three games of this five-game series, he eventually beat AlphaGo, Google's supercomputer, in game four. As Wired magazine reporter Cade Metz describes, the final game was another intense match-up between like-minded competitive and deeply competent players, one human and the other not. But what's less clear is whether the computer lost this round because it began to behave in human-like ways when Lee Sedol made a brilliant and surprising move.
In the middle of the contest, Go aficionados agreed, Lee Sedol was behind. But he built up to that move in the center of the board and turned the tide. "Lee Sedol played a brilliant move. It took me by surprise. I'm sure that it would take most opponents by surprise. I think it took AlphaGo by surprise," [game commentator Michael] Redmond said.
As he prepared for this fourth match-up with AlphaGo, Lee Sedol noted:
"Although AlphaGo is a strong program, I would not say that it is a perfect program," he said. "Yes, compared to human beings, its moves are different and at times superior. But I do think there are weaknesses for AlphaGo."Although AlphaGo claimed the advantage in this DeepMind Challenge Match, Lee Sedol achieved an impressive human win.