It turns out that Google’s AlphaGo isn’t unstoppable. Yesterday, the AI had won three out of the five matches in its series against Lee Sedol, but today, the computer’s human opponent triumphed.
Lee Sedol was upset after his loss to the system yesterday, apologizing for his failure to beat the machine. Today, he was far more upbeat after his win, noting that “I’ve never been congratulated so much just because I won one game!”
According to AlphaGo’s team, the machine made an error early in the game, but didn’t realize that it had done so until ten moves later:
The machine resigned after five hours, leaving Sedol the victor. As the pair have played one another, it seems that they’ve been learning and understanding each other better with each match, according to South Korean commentator Song Taegon:
It seems Lee Sedol can now read AlphaGo better and has a better understanding of how AlphaGo moves. For the 5th match, it will be a far closer battle than before since we know each better.
With that in mind, it’ll be interesting to see how the fifth and final game ends up. That match will be played on Tuesday, March 15th. Has Sedol learned enough about the machine and how it plays to triumph once again?
Despite the win, the machine has won eight out of the nine games that it’s played: while its winning streak is now broken, it’s an amazing triumph for artificial intelligence: Go is an incredibly difficult game to play, with an enormous number of possible moves to compute.
Still, the loss for the machine shows that there’s still some glimmer of hope for humanity.
Contact the author at andrew.liptak@io9.com.