“In the first three games, AlphaGo bludgeoned Lee with a calculating efficiency that mystified the 33-year–old Korean. Then in Game 4, Lee responded to the challenge of artificial intelligence with new tactics. He attacked AlphaGo, aggressively sought to hem it in, and in a transcendent moment of genius laid down a lone white pebble that one Go champion dramatically called the ‘hand of god.’ He won.”