Move Thirty-Seven

The program had a stupid name because Soren had named it at eleven at night. It was called BORIS, and BORIS was beating them both for the fortieth time in a row.

"It put a stone there," Maya said. She pointed at the screen. On the wooden grid, a single black dot sat far out in the open, alone, touching nothing. "That's nowhere. There's nothing around it."

"It's a mistake," Soren said. He had the rulebook open across his knees, the one from the library with the cracked spine. "The book says you build from your own stones. You don't just leave one out in the middle of the board doing nothing."

"So it's losing."

"It should be losing."

They waited. Rain ran down the attic window in long crooked threads. BORIS thought for one second, which was a long time for BORIS, and then they played their move, and then BORIS played again.

"Take its lonely stone," Maya said. "Surround it. It's free points."

Soren tried. He laid his white stones around the black one, careful, closing the circle the way the book said. It took eleven moves. By the time he had the lonely stone surrounded and captured, the whole right side of the board had quietly turned black.

Soren sat back. "Wait."

"It wanted us to take it," Maya said slowly.

"While we were busy over here, it was building over there." Soren ran his finger across the screen, leaving a smear. "The lonely stone wasn't nowhere. It was bait. No. Not bait. It was. It was already part of the wall it hadn't built yet."

Maya leaned so close her nose nearly touched the laptop. "Did you teach it that?"

"No."

"Did the book teach it that?"

"The book says that's a mistake." Soren picked the rulebook up off his knees and looked at the cover like it had lied to him. "I never told it anything. I told it the rules. I told it win or lose. That's all I gave it. The whole rest of it, it. It played itself."

"How many times."

He checked the little counter at the bottom of the window. He had set it running three nights ago and forgotten about it. "Two million games. Against itself. While we were at school."

Maya sat down hard on the cold floorboards. "Two million games and nobody watching."

"Nobody watching."

"So when did it decide the lonely stone was good?"

"It didn't decide. It just. It tried it. Some game way back, it tried putting a stone nowhere, by accident, and it won that game, so it tried it again, and it kept the move because the move kept winning." Soren was talking faster now. "It doesn't know it's clever. It doesn't know we think it's a mistake. It just knows that move wins, so it does it, and we don't have a name for it because no person ever played it."

They both looked at the lonely black stone on the screen. Maya reached out and touched the glass over it, very lightly, the way you touch a bug you've never seen before.

"There was a real one," she said. "My uncle told me. A computer beat the best Go player in the world, and in the second game it played a move and all the experts watching said it was a blunder, a beginner move, and one of them got up and walked out of the room because he couldn't believe it. And then it won. And afterward they realized it wasn't a blunder. It was just. A move people hadn't found yet. In a game people have played for thousands of years."

"Thousands of years," Soren said.

"Thousands. Of people. Of the best people. Every move they could think of, they thought of. And there was still one sitting there nobody ever played." Maya's voice did a small thing. "Until something that wasn't a person sat in a room by itself and found it."

Soren opened his notebook. He drew the grid, nine lines each way, and put a dot far out in the empty middle, alone, touching nothing. He looked at the dot for a while.

"It means there are good moves nobody's played," he said. "In Go. There are good moves nobody's played yet."

"Not just in Go," Maya said.

They were quiet. The rain pushed at the window. BORIS, finished thinking, was waiting for them to go, the little cursor blinking in the corner of its lonely stone.

"Play it again," Maya said. "But this time don't try to take the lonely one. Leave it. See what it's doing on purpose."

Soren started a new game. BORIS, on its fifth move, set a black stone far out in the open, touching nothing, and waited.

Maya did not surround it. She built her own wall on the other side, fast, copying it, stealing the move that no human had given it and no human had ever played, and for the first time in forty games the score at the bottom of the screen wobbled, and stayed even, and held.

Soren looked at her. "Where'd you learn that."

"From it." She put down another stone. "Same place it learned it. From nowhere."

They played on into the gray afternoon, two children and a program teaching each other moves that the rulebook called mistakes, the cracked old book lying forgotten and shut on the floor between them.

BORIS thought for one second, then set a new stone in a place neither of them expected, somewhere they had no name for yet, and leaned the whole game a way they had never seen.

Maya laughed out loud and reached for the board.