"You’ll play black," he said. He set a group of black stones on the board, crisply clicking them down. "Now I’ll demo the game a bit, before we start. You place your stones down like this, one at a time. The groups of stones gain strength from their links, from the network that they form. And the groups have to have eyes, blank eyes inside the network. That’s a crucial point." He placed a blocking chain of white stones around the black group. "A single eye isn’t enough, because I could blind that eye with one move, and capture your whole group. I could surround the whole group, drop into the middle, blind your eye, and just remove the whole group, like this. But with two eyes—like this?—the group becomes a permanent feature on the board. It lives forever."