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The computer tries its hand

Machine to face poker champion

Phil Laak, a top poker professional, might just beat the computer -- this time. Phil Laak, a top poker professional, might just beat the computer -- this time. (ASSOCIATED PRESS/file/2006)

NEW YORK -- Poker champion Phil Laak has a good chance of winning when he sits down this week to play 2,000 hands of Texas Hold'em -- against a computer.

It may be the last chance he gets. Computers have gotten a lot better at poker in recent years; they're good enough now to challenge top professionals like Laak, who won the World Poker Tour invitational in 2004.

But it's only a matter of time before the machines take a commanding lead in the war for poker supremacy. Just as they already have in backgammon, checkers, and chess, computers are expected to surpass even the best human poker players within a decade. They can already beat virtually any amateur player.

"This match is extremely important, because it's the first time there's going to be a man-machine event where there's going to be a scientific component," said University of Alberta computing science professor Jonathan Schaeffer.

The Canadian university's games research group is considered the best of its kind in the world. After defeating an Alberta-designed program several years ago, Laak was so impressed that he estimated his edge at a mere 5 percent. He figures he would have lost if the researchers hadn't let him examine the programming code and practice against the machine ahead of time.

"This robot is going to do just fine," Laak predicted.

The Alberta researchers have endowed the $50,000 contest with an ingenious design, making this the first man-machine contest to eliminate the luck of the draw as much as possible.

Laak will play with a partner, fellow pro Ali Eslami. The two will be in separate rooms, and their games will be mirror images , with Eslami getting the cards that the computer received in its hands against Laak .

That way, a lousy hand for one human player will result in a correspondingly strong hand for his partner in the other room. At the end of the tournament the chips of the humans will be added and compared with the computer's.

The two-day contest, beginning today, takes place not at a casino, but at the annual conference of the Association for the Advancement of Artificial Intelligence in Vancouver, British Columbia. Researchers in the field have taken an increasing interest in poker over the past few years because one of the biggest problems they face is how to deal with uncertainty and incomplete information.

It is much harder for computer programmers to teach computers to play poker than other games. In chess, checkers, and backgammon, every contest starts the same way, then evolves through an enormous, but finite, number of possible states according to a consistent set of rules. With enough computing power, a computer could simply build a tree with a branch representing every possible future move in the game, then choose the one that leads most directly to victory.

That's essentially the strategy IBM's Deep Blue computer used to defeat chess champion Gary Kasparov in their famous 1997 match. No computer can calculate every single possible move in a chess game, but today's best chess programs can see an astounding 18 moves ahead.

Yet poker involves not just myriad possibilities but uncertainty, both about what cards the opponent is holding and, more important, how he is going to play them.

"It's mandatory for you to understand how the other guy approaches the game. This is critical information in poker, and it's not true of any of these other games that we've studied in academia," said Darse Billings, who has worked on the robot for 15 years -- except for a three-year break to play poker professionally.

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