ROUND TWO: Google's DeepMind AI just beat a human Go champion for a second time

Google's DeepMind AI just beat a human world champion at the ancient game of Go for a second time, cementing its historic achievement.

The AlphaGo software played Lee Sedol in South Korea on Thursday, in the second of a series of five planned matches.

It was a closely fought game, with both players going into overtime.

The games are a significant milestone for AI research. Go is a simple game but has been notoriously difficult for computers to master because of the sheer number of potential moves. While AI programs began being able to beat human champions at chess decades ago, the best Go players in the world have always been able to outsmart Go-playing software — until now.

Go expert Yoo Changhyuk said Lee tried to make "difficult moves to agitate AlphaGo" in the first game." Today, he tried the opposite — he played safe and entered the endgame," he said. "He made some mistakes, which I think caused the defeat."

Google DeepMind CEO and cofounder Demis Hassabis said in a press statement: "That was dramatic to say the least! Lee Sedol put up an incredible performance and had our expert commentators divided over the result until the end. AlphaGo played some really surprising and beautiful moves in this game."

Lee added: "Yesterday, I was surprised, but today I am quite speechless. If you look at the way the game was played, it was a very clear loss on my part. Yesterday I felt like AlphaGo played certain problematic positions, but today I felt that AlphaGo played a near perfect game. There was not a moment I felt like its moves were unreasonable."

If you’re not familiar with Go, it’s a two-player turn-based strategy game. Each player puts down either black or white stones in an attempt to outmaneuver and surround the other player. It's easy to pick up but takes years to master.

AlphaGo won the first game On Wednesday after Lee Sedol resigned after 186 moves.

Before the first game, Lee Sedol had said he was "confident" about his prospects, telling reporters he was aiming for a 5-0 victory across all the games. But there's now a real possibility that AlphaGo could win every game.

The contenders need to win at least three games to win the Challenge Match. Victory for AlphaGo is now in sight.

You can watch the entire game here:

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