The world’s best weiqi (Go) player and Chinese prodigy, 19-year-old Ke Jie, lost the battle against AlphaGo in their second match on Thursday. With a previous defeat in the first round, the Artificial Intelligence (AI) program has won the three-match series, even before the final round on May 27 takes place.

Fighting was the main theme of Thursday's match. Ke tried to complicate the situation as much as possible, seeking small battles at the bottom of the board with AlphaGo.

A game from the future

Ke Jie showed extremely high skills at the beginning, with the initial part of the match being “perfect,” according to AlphaGo’s evaluation.

“I became excited like playing with a human,” Ke said after the match, “for the first time I thought it’s possible for me to win.”

Ke's status was very different from May 23's match. /DeepMind Screenshot

“But I made some mistakes out of the excitement later on. Sorry for that,” Ke added.

AlphaGo’s creators hailed Ke’s performance after seeing the machine’s evaluation data, which showed Ke had been playing perfectly during the first 100 moves.

“At roughly 50 stones, it agrees with all the moves,” one of the technicians told reporters, “This is the closest game we’ve seen anyone played with AlphaGo.”

“I think we saw a game from the future,” said Demis Hassabis, leader of the AlphaGo team.

A naughty machine?

“AlphaGo is not polite at all,” some weiqi fans said during watching the match.

Ke analyses the match result. /Web Photo

According to tradition, the first stone of a match should be placed around the top-right corner of the board, from the view of the player.

This gives convenience for the opponent to put the next stone.

But when AlphaGo played first today, it put the stone around the bottom-right corner, on its own side.

Hassabis explained the machine’s improper behaving. “AlphaGo doesn’t know up and down. Sorry for that,” he said.

Ke said he’s fine with this.

Ke and Hassabis after the match. /Web Photo

'Let it go first'

During the after-match analysis, Ke Jie raised a suggestion to play white again in the last match.

"I saw the AlphaGo analysis, and found the one who played behind has a better rate of winning," Ke said, "and when I played as white today, I had better performance."

Ke observes closely at the board after the match. /Web Photo

Hassabis agreed to let AlphaGo play first on May 27.

“I don't want euthanasia, or lose easily. I'll fight till the end,” Ke said.