Human Go champ scores surprise victory over supercomputer

March 13, 2016
South Korean Go grandmaster Lee Se-Dol (R) makes a move during the first in a five-game series against AlphaGo in Seoul on March
South Korean Go grandmaster Lee Se-Dol (R) makes a move during the first in a five-game series against AlphaGo in Seoul on March 9, 2016

A South Korean Go grandmaster on Sunday scored his first win over a Google-developed supercomputer, in a surprise victory after three humiliating defeats in a high-profile showdown between man and machine.

Lee Se-Dol thrashed AlphaGo after a nail-biting match that lasted for nearly five hours—the fourth of the best-of-five series in which the computer clinched a 3-0 victory on Saturday.

Lee struggled in the early phase of the fourth match but gained a lead towards the end, eventually prompting AlphaGo to resign.

The 33-year-old is one of the greatest players in modern history of the ancient board game, with 18 international titles to his name—the second most in the world.

"I couldn't be happier today...this victory is priceless. I wouldn't trade it for the world," a smiling Lee said after the match to cheers and applause from the audience.

"I can't say I wasn't hurt by the past three defeats...but I still enjoyed every moment of playing so it really didn't damage me greatly," he said.

Lee earlier predicted a landslide victory over Artificial Intelligence (AI) but was later forced to concede that the AlphaGo was "too strong".

Lee had vowed to try his best to win at least one game after his second defeat.

Described as the "match of the century" by local media, the game was closely watched by tens of millions of Go fans mostly in East Asia as well as AI scientists.

The most famous AI victory to date came in 1997, when the IBM-developed supercomputer Deep Blue beat the then-world class chess champion Garry Kasparov.

But Go, played for centuries mostly in Korea, Japan and China, had long remained the holy grail for AI developers due to its complexity and near-infinite number of potential configurations.

'More creative than we imagined'

Demis Hassabis, the head of the AlphaGo developer Google DeepMind, has described Go as the "Mount Everest" for AI scientists.

"Lee Se-Dol was an incredible player and was too strong for AlphaGo," Hassabis said after Sunday's match.

"It was doing well...but then, because of Lee's fantastic play, it was pressurised into some mistakes," he said, describing the loss as a "valuable" way to fix the problems with the supercomputer.

"Actually we are very happy because this is why we came here, to test AlphaGo and its limit and find out what its weaknesses were," he said.

Lee said those weaknesses included a difficulty in responding to certain unexpected plays by an opponent, which led to more mistakes.

Go involves two players alternately laying black and white stones on a chequerboard-like grid of 19 lines by 19 lines. The winner is the player who manages to seal off more territory.

On the 78th move, Lee placed a stone unexpectedly in the middle section of the board, stunning many experts and confusing the AlphaGo.

Hassabis later tweeted that the AlphaGo made a "mistake" on the following 79th move and only realised it several moves later.

AlphaGo uses two sets of "" that allow it to crunch data in a more human-like fashion—dumping millions of potential moves that human players would instinctively know were pointless.

It also employs algorithms that allow it to learn and improve from matchplay experience.

"I think AlphaGo is far more creative than we ever imagined. It makes us to rethink all the conventional rules and knowledge we learned in Go," said Lee Hyun-Wook, a TV commentator and professional Go player.

The last match is to be held on Tuesday in the Four Seasons Hotel in Seoul.

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1 / 5 (2) Mar 13, 2016
Question now becomes; is computer crying/pissed or ready to kill???
5 / 5 (1) Mar 13, 2016
Call subroutine {Activate Skynet};
Whydening Gyre
4.6 / 5 (5) Mar 13, 2016
Tried to learn GO back in early 70s when I was in Korea. Ha!
The game was way harder to learn than the Korean language...:-)
Needless to say - Hats off to anyone (or anything) that manages to play it competently...
4 / 5 (1) Mar 13, 2016
PhotonX, funny comment with proper syntax!

5 / 5 (1) Mar 13, 2016
I think AlphaGo is far more creative than we ever imagined.

I don't think it's creative enough yet to throw a game, but it will certainly be a pivotal day, when it does.
5 / 5 (1) Mar 13, 2016
Lee Sedol was in time trouble in every game, he should have been given an extra hour in total because we are testing the strength of AI not it's speed we already know computers are faster.
not rated yet Mar 14, 2016
This would be the final game as fried electronics smoke came out of AI. After all the "deep neurals networks" are not deep enough.
not rated yet Mar 14, 2016
A case of emergent empathy/sense of humour? Having been trained to play in a more human-like fashion, perhaps part of alphaGo's initial 3 game wiinning success was not merely due to a cold strategic optimization of outcomes by the AI, but that additionally, its training "accidently" came to recognise and embody aspects of human psychology via human games - that even humans couldn't recognise in the patterns - to the point the various quasi-psychological behaviourable traits that gave it leverage, became significantly encoded as part of its understanding of the game.

not rated yet Mar 14, 2016
....Such that, emergent conscious-like tendencies beyond playing the game itself, perceived Lee Sedol's strategy as an act of desperation causing AlphaGo to feel sympathy for the great man; or perhaps AlphaGo's circuits were so amused - in an AI sort of way - it that rewarded Lee Sedol the win for evoking "sensations", that it similarly "experiences" due to its more evolved AI state finding higher order divergent solutions in weird/incongruous plays to have some rare but recognizable benefit which occasionally transcends the strategies of ordinary play, and are of an entirely different class that, AI induced "amusement" states/feedbacks are in some sense the best way to encapsulate the awareness that this it is so.

not rated yet Mar 14, 2016
It was pretty obvious that Lee was intimidated by αGo even before the first game. He finally figured out that "sticking to the book" would play into the A.I. strengths. That's a good thing. Now perhaps the 5th game will be interesting, if he can replicate his unconventionality. I have my doubts. Seems to me that α-Go has changed the game forever. (BTW, 10^(10^140) is nowhere near ∞, although the difference escapes me :)

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