Computer beating top human Go professional

Lee Sedol vs AlphaGo in Seoul

On Wednesday Lee Sedol, a 33-year-old master of the ancient Asian board game Go, sat down in the South Korean capital, Seoul, a five games against a computer. His opponent is Alphago, a program built by the Google subsidiary DeepMind. Lee, who has been a Go professional for 21 years, is currently ranked among the top three players in the world.

AlphaGo is a computer program developed by Google DeepMind, using a combination of machine learning and tree search techniques, combined with extensive training, both from human and computer play. This Nature paper, published in January 2016, describes the technical details behind a new approach to computer Go – one that combines Monte-Carlo tree search with deep neural networks, trained by supervised learning from human expert games, and by reinforcement learning from games of self-play. We will be providing more details in the near future.

In October 2015 AlphaGo became the first computer program to beat a professional Go player by winning 5-0 against three-times European Champion Fan Hui (2-dan pro).

Listen to Demis Hassabis, CEO of Google’s DeepMind, explain the background of this AI enterprise

The author of this report has known Demis for a long time – here's a small extract from a very readable report on the match in The Guardian:

What impact would a DeepMind victory have?

The chess world has had two decades to live with the fallout of Deep Blue’s victory over Kasparov. But Frederic Friedel, a computer chess pioneer and the founder of the news site ChessBase, argues that it’s possible to overstate the effect the victory had. “AlphaGo winning won’t change the world of Go. It’s like you’ve built a bicycle or a car that can go faster than Usain Bolt, and you say: ‘Look at how fast it is!,” does this mean the world ends for athletics? No, it doesn’t.”

Friedel, who first met Hassabis as “a cocky little kid who came for a dinner with Gary [Kasparov] and myself in London, and told us about some software he was developing”, does have a warning for Go players, though. “The advent of bicycles and motorbikes did not make athletes give up in despair: they just went on racing each other without these machines. But there is a grave difference to the chess analogy: a 200-metre runner cannot secretly use the assistance of a bicycle, but a chess player can most certainly get his moves surreptitiously from a computer.

“Cheating in chess is becoming a serious problem, and it will become more acute as technology progresses. That will change the game dramatically – not the fact that computers are stronger than humans.”

You may also want to listen to a radio interview the BBC World Service conducted with Friedel, which contains some provocative thoughts on artificial general intelligence (AGI). If you think Frederic's view are completely outlandish listen to Sam Harris on the subject (starting at 8:50 min).

The match in Seoul

A virtual encounter between Lee Se-dol and Demis Hassabis before the match [photo Yonhap/EPA]

Here is the schedule for the next four games – join the 1.5 million spectators that watched game one on YouTube. The $1 million dollar five-game challenge match is being staged in Seoul. Match commentary by Michael Redmond (9-dan pro) and Chris Garlock.

As we go into print – well, into HTML – AlphaGo has just won the second game, bringing the total score to 2-0 for the computer. The third game is on Saturday and well worth watching – listening to the commentators actually teaches you a lot about the game

Early comments

As mentioned above this is not the last you will be hearing about AlphaGo and DeepMind on our news page. But here are some quick reactions from two experts: first from Ken Thompson, who in the late 1970s and early 1980s built the first hardware chess machine, Belle, that won the computer chess world championship and became the first master-level machine in 1983. Ken, who abhors capitalisation and apostrophes like nature a vacuum, said: "i am very impressed. i didnt think it would happen in my lifetime."

John Nunn, on the other hand, wrote us: "I suspect that the 'hard for computers to master Go' thing is a bit of a myth. If the same effort had been put into computer Go as was put into chess, they would probably have reached this point a long time ago."

Tell us what you think. If you need more information visit the AlphaGo page on Google DeepMind – or consult these recent press stories on the match (you don't need to read all 13,000 of them). Finally this is where to watch the next three games of the match live on YouTube.