The First Man-Machine
Chips are down as man beats poker machine
$50,000 challenge sees computer fall short - but makers say they'll be back
Dan Glaister, in Los Angeles
They didn't blink. They didn't tell. Even after Polaris took the second round, the Unabomber and his accomplice stuck to their game. Finally, deep into the night, after four rounds of Texas hold 'em, Polaris folded once and for all. The game was over. The humans had beaten the machine. Just.
Far away from the kitsch glamour of Las Vegas, with not a showgirl or a hustler in sight, two professional poker players from Los Angeles took on a computer program in a hotel in Vancouver on Monday and Tuesday. Billed as the "First Man-Machine Poker Championship", the event staged at the annual meeting of the Association for the Advancement of Artificial Intelligence offered prize money of $50,000 (£25,000) to the winner of four hands of poker.
For Ali Eslami and Phil "the Unabomber" Laak - so named because he wears a hooded sweatshirt and sunglasses - the money was small change, but the stakes were high.
"I literally felt the same feeling that you would have if you beat 500 people in a tournament and won a million dollars," Laak said after the game, which ended to the sound of whoops and cheers from the watching crowd of hundreds as the humans vanquished the computer. "We won, not by a significant amount, and the bots are closing in."
Playing against the computer was more exhausting than any other game he had played, Eslami said. "I really am happy it's over. I'm surprised we won ... it's already so good it will be tough to beat in future."
Polaris has been 16 years in development at the University of Alberta in Canada. While computers have previously mastered humans at games such as chess and draughts - chess world champion Gary Kasparov was no match for IBM's Deep Blue a decade ago - researchers have been keen to develop poker software in the belief that it might be more applicable in other fields.
"I contend that poker is harder than chess for computers, and the research results that come out of the work on poker will be much more generally applicable than what came out of the chess research," Jonathan Schaeffer, the lead scientist behind the programme, told the New York Times. His team won the world draughts championships in 1994 and said earlier this month that they had developed a program that could not lose at draughts.
But poker is altogether more sophisticated. The computer, like its human counterparts, knows how to bluff. And unlike its chess and draughts counterparts, which require an enormous memory to consider every potential move, Polaris runs for weeks before a game, creating 10 different "bots" which have their own playing style.
Organisers of the event attempted to remove the element of luck by putting the human players in separate rooms. The computer played both humans simultaneously, with one human and the computer dealt identical hands. If Eslami was dealt a royal flush in one room, Polaris would have a royal flush in its game against Laak.
The separation also eliminated one of the most important aspects of poker, the "tell" or giveaway signal when a facial tic or restlessness can reveal a player's strategy.
The first round - each round consists of about 500 hands - ended in a draw, although the computer's winnings were marginally higher than those of the humans. But Polaris won the second round heavily, leading Eslami to comment that "Polaris was beating me like a drum".
But on the second day things changed, and a strategic gamble by the computer's human handlers may well have cost Polaris its $50,000.
For the first two rounds Dr Schaeffer's team ran a single bot. But for the third round they substituted a more sophisticated program that was supposed to add a level of "learning", deploying different bots as necessary.
The strategy backfired. The humans easily won the third round, levelling the contest.
In the final round, although Polaris won a sizeable pot of $240 with a royal flush beating Eslami's three-of-a-kind, the humans again prevailed, winning $570.
Darse Billings, a scientist on the Polaris team and a former professional poker player, thought the humans had played "brilliantly".
But he had a prediction from the future: "I wouldn't be surprised if we can beat them tomorrow," he said.