But now even Ke, the reigning top-ranked Go player, has acknowledged that human beings are no match for robots in the complex board game, after he lost three games to an AI that mysteriously popped up online in recent days.

The AI turned out to be AlphaGo in disguise.

Source: The AI “Master” bested the world’s top Go players—and then revealed itself as Google’s AlphaGo in disguise — Quartz