S. Korean Go player loses to Google AI

By Joo Kyung-don

SEOUL, March 9 (Yonhap) -- Humans 0, machines 1.

Google's artificial intelligence (AI) program AlphaGo beat top-class South Korean Go player Lee Se-dol in the ancient board game Go Wednesday as the self-learning machine stunned the world by taking the lead at the historic five-match man-versus-computer tournament.

In a landmark showdown held at the Four Seasons Hotel in Seoul, AlphaGo, the AI designed by Google's London-based firm DeepMind, beat Lee by resignation in 186 moves after playing nearly three and a half hours.

Lee, a ninth-dan player who went pro at the age of 12, will play his second match against AlphaGo with a shot at revenge at the same venue on Thursday. The 33-year-old is also slated to face the human-like algorithm on Saturday and Sunday before wrapping up the tourney next Tuesday.

The tournament is scheduled to continue even after three wins by either side, as Google wants to give more data to AlphaGo, which already surprised the Go community after shutting out European Go champion and second-dan Fan Hui 5-0 last October.

Lee, who has won 47 Go events including 18 international trophies, said last month that he would win the tourney with a score of 5-0 or 4-1 in his favor, but just a day before the matchup the Go player stepped back by saying that those scores may not happen.

His concerns turned into reality.

Playing in a room behind closed doors, Lee opened the match by taking the 3-4 point in the right top corner. Going second with white stones, it took 1 minute and 30 seconds for AlphaGo to make its first move. The machine eventually settled for the "flower point" or 4-4 point in the left top corner.

Lee, who brought a cup of coffee with him, then chose the 3-4 point in the right bottom, signaling that he will secure the right area of the board, while AlphaGo, whose moves were actually placed on the board by Google DeepMind programmer and amateur 6-dan Go player Aja Huang, went with another standard move by occupying the flower point in the left bottom to take the left side.

Lee, who is known for his aggressive and unconventional style of play, placed his third black stone near the AlphaGo's left-top flower point, but the engagement broke out in the top right corner and started moving into the center of the board.

Although there were moves from AlphaGo which South Korean commentators tagged as "strange," the machine didn't back off against Lee's effort to tweak the game. Looking frustrated, Lee at one point even left his seat to take a brief rest.

In the latter half of the match, Lee tried to defend his territories from the right side, but AlphaGo's cold, fatal moves narrowed down the winning chances for Lee and forced the South Korean to drop the game.

Go, known as "baduk" in Korea, originated in China more than 2,500 years ago. It involves two players alternately putting black and white stones on a checkerboard-like grid of 19 lines by 19 lines. The object is to claim larger territories than one's opponent by surrounding vacant areas of the board using one's own stones.

Go has been viewed as one of the hardest games for computers to master. Google said the possible number of board configurations of Go is larger than the number of atoms in the universe.

In this special showdown organized by Google and the Korea Baduk Association (KBA), the matches will be played under Chinese rules in which a player who places white stones receives 7.5 compensation points at the end of the match. Scoring calculations will also be based on Chinese rules, also known as "area scoring," in which a player's score is determined by the number of stones that the player has on the board and territories earned.

Each player has two hours per match with three lots of 60 seconds overtime counting after they have finished their allotted time.

kdon@yna.co.kr
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