Skip to Content

Go Master Salvages a Victory, Showing Ingenuity in the Face of a Formidable AI

Google’s AlphaGo AI beat one of the world’s best players, but was finally outfoxed when its opponent exploited weaknesses in the way it works.
March 14, 2016

Lee Sedol, the 18-time world Go champion, struck a small victory for humankind over the weekend by finally defeating Google’s masterful Go-playing computer, AlphaGo. Sadly for Sedol, and for those cheering humanity’s champion, by that game the best-of-five series was already lost. However, his fightback highlights the way that human ingenuity can overcome brute-force machine learning.

The website Go Game Guru has a very interesting analysis of the fourth game in the historic match between AlphaGo and Sedol:

AlphaGo is very good at estimating its probability of winning. It appears to be able to do this even more accurately than the best human players. With the help of this skill, AlphaGo seems to be able to manage risk more precisely than humans can, and is completely happy to accept losses as long as its probability of winning remains favorable.

The Japanese have a name for this style of play, as it closely resembles the prevalent style of Japanese professionals over the previous few decades. They call it "souba" Go, which means something like "market price."

What Lee and his [team] had realized, was that they needed to completely upend the market.

In other words, Sedol did something that doesn’t involve reasoning over the position of pieces on the Go board. He considered how AlphaGo works, and sought to exploit weaknesses in its design.

AlphaGo is undoubtedly a fantastically clever piece of AI. The program combines two well-established AI techniques—machine learning and tree analysis—to master a game that previously seemed too complex and subtle for machines. So Sedol chose to pursue a strategy that made AlphaGo’s ability to judge risk less useful. And, on turn 79, he came up with an incredibly clever move to turn the game decisively in his favor. 

Sadly, it’s too late for Sedol to claim the $1 million purse. But it’ll be interesting to see if Sedol can find further weaknesses in AlphaGo in the fifth and final game.

(Read more: The Verge, Go Game Guru, "Google’s AI Masters Go a Decade Earlier than Expected")

Keep Reading

Most Popular

Europe's AI Act concept
Europe's AI Act concept

A quick guide to the most important AI law you’ve never heard of

The European Union is planning new legislation aimed at curbing the worst harms associated with artificial intelligence.

Uber Autonomous Vehicles parked in a lot
Uber Autonomous Vehicles parked in a lot

It will soon be easy for self-driving cars to hide in plain sight. We shouldn’t let them.

If they ever hit our roads for real, other drivers need to know exactly what they are.

supermassive black hole at center of Milky Way
supermassive black hole at center of Milky Way

This is the first image of the black hole at the center of our galaxy

The stunning image was made possible by linking eight existing radio observatories across the globe.

transplant surgery
transplant surgery

The gene-edited pig heart given to a dying patient was infected with a pig virus

The first transplant of a genetically-modified pig heart into a human may have ended prematurely because of a well-known—and avoidable—risk.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.