HUMAN NATURE

We've Made Our Match

By William Saletan
Sunday, May 13, 2007

Ten years ago this week, a computer beat the world chess champion in a six-game match. Since then, human champs have played three more matches against machines, scoring two draws and a loss. Grandmasters are being crushed. The era of human dominance is over.

Chess was supposed to be a bastion of human ingenuity, an art machines would never conquer. Now they're conquering it. The smarter they get, the more threatened we feel.

Don't be afraid. We, too, are getting smarter, and computers are a big reason why. They're not our enemies. They're our offspring -- our creations, helpers and challengers.

We certainly needed the challenge. Chess computers, in particular, have exposed our complacency. Grandmasters used to dismiss computers as calculators, unfit for elite competition. Our vanity was so blinding that in 1997, when world champion Garry Kasparov lost to a machine called Deep Blue, he implied that the computer had received human coaching during the match.

Computers kept winning, and we kept whining. In postgame press conferences, players swore that they'd been winning right up until the moment when, for unclear reasons, they lost. Five months ago, the current champ, Vladimir Kramnik, overlooked an instant checkmate by his artificial opponent, Deep Fritz. "I rechecked this variation many times and analyzed quite far ahead," Kramnik protested. "It seemed to me I was winning."

Kramnik's blunder was no accident. It happened because of flaws in the human brain. We thought we were smarter than computers for two reasons. First, we could choose a goal and figure out how to get there, whereas computers had to start with the available moves and see where they led. Second, computers had to think through every possible move, whereas we could recognize crucial patterns and focus on the moves that mattered. But that's why Kramnik missed the checkmate: It looked different from the usual threat pattern, and he was thinking too far ahead. Even the best brain sometimes needs computer assistance.

The remarkable thing about us isn't our supremacy over computers. It's our interaction with them. Yes, chess programs have been getting smarter. But they didn't do that on their own. Humans design the hardware and write the code. Grandmasters test and refine it. The machines get smarter because the code gets subtler because the programmers get wiser.

In the old days, chess programs went around killing enemy pieces at every opportunity. Their human opponents understood that in chess, as in war, other factors often matter more: territorial control, mobility, initiative, reach, coordination, supply lines, impregnability and safety from decapitation. By trading material for these advantages, the humans won. So programmers taught the machines to recognize and consider the same factors.

Unable to win with their old tricks, human players learned new ones. They played quirky openings to throw computers off script. They plotted attacks a dozen moves ahead. They hunkered down in defenses that to a computer looked impregnable. They cluttered the battlefield with obstructions, making it harder for computers to see threats or payoffs. They left irrelevant pieces on the board to absorb the machines' attention. It was a whole new game. The humans named it "anti-computer chess."

Now programmers are adding a third layer: anti-anti-computer chess. They're teaching machines to break old habits, see through clutter and force the wide-open bloodbaths at which computers excel. In 2003, Deep Junior flummoxed Kasparov with a kamikaze attack unprecedented in computer annals. Last year, when Kramnik forced Deep Fritz off its opening script, the program invented a new variation and went on to win the game.

In the big picture, whether the computer beats us isn't important. Either way, it's a human triumph. In fact, it's a greater human triumph when the computer wins. As a player, you can conceive a brilliant move without understanding where it came from. As a programmer, you have to do something much harder: articulate rules that will generate such brilliance.

From microwaves to cellphones to word processors, computers are extending our intelligence, forcing us to higher levels of thought. Pitting my brain against yours is hard. Pitting my program against yours -- teaching one machine to spot and exploit another's subtle flaws -- is much harder.

When the cosmic game between humans and computers is complete, here's how the sequence of moves will read. In the opening, we evolved through engagement with nature. In the middle game, we projected our intelligence onto computers and co-evolved through engagement with them. In the endgame, we merged computers with our minds and bodies, bringing that projected intelligence back into ourselves. The distinction between human and artificial intelligence will turn out to have been artificial.

You don't need to be a machine to see the endgame unfolding. Last year, a Missouri teenager reached the third level of Space Invaders by operating the gun through wires attached to his brain. Today, the European Union is developing a cybernetic dental implant that can medicate you according to a dosage and schedule programmed by your doctor. In Russia, Kasparov has retired from chess and moved on to what he calls "larger competition" -- leading a movement against the country's authoritarian regime. You can read all about it on his Web site. All you need is a computer.

human@slate.com

William Saletan covers science and technology for Slate, the online magazine at www.slate.com.


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