PITTSBURGH » The humans won!

The question now, though, is how long can they hold off the computer?

The two-week long “Brains Vs. Artificial Intelligence” poker tournament at Rivers Casino on the North Side, closely watched around the world by poker and artificial intelligence enthusiasts, concluded Friday morning.

Four of the world’s best Heads-Up, No-Limit, Texas Hold ‘em poker players came out on top, beating Claudico, the computer poker program designed over the last decade by a team of researchers at Carnegie Mellon University, by a combined $732,713 theoretical dollars or chips. (No real money was wagered.)

“It’s definitely been a good run,” said Bjorn Li, who finished with the biggest lead over Claudico, $529,033 ahead. That earned him $44,676 from the $100,000 prize pot that the casino and co-sponsor Microsoft put up for the players to divide based on the outcome of the tournament. Doug Polk, the world’s top-ranked online player, won $26,734, Dong Kyu Kim won $18,589, and Jason Les won $10,000.

Three of the four human players — all four ranked in the top 10 in the world in online, Heads-Up, No-Limit Texas Hold ‘em — won more than they lost against Claudico. The humans also won 10 of the 13 days of the tournament, with 80,000 hands of poker played in total.

Although the gap between the humans and Claudico seemed large, Tuomas Sandholm, the CMU computer science professor who has overseen Claudico’s development, said that when you consider the humans’ win rate, and the fact that the total amount wagered over the two weeks in theoretical dollars was $170 million, $730,000 is not that much.

“From a statistically significant perspective,” Sandholm said during a news conference this morning marking the end of the tournament, “it is still a statistical draw.”

Polk, who had the second highest lead on Claudico to Li — $213,671 — followed Sandholm to the microphone to respectfully disagree.

The humans’ win rate — 9.1 big blinds per 100 hands played — indicates “a fairly close match,” Polk said.

“But I wouldn’t say that’s a tie,” he said. “I’d say the humans have the edge.”

All sides — the players, CMU and Rivers Casino — are interested in having another tournament in the future to see if an improved Claudico can come out on top and settle the debate.

Sam Ganzfried, one of Sandholm’s Ph.D. students who helped design Claudico, said given everything they will learn from reviewing how the 80,000 hands were played: “I think we can have a new program that can beat the humans in a year.”

After two straight weeks of poker, all four players conceded they were tired from playing up to 12 hours a day, not including two to four hours of analysis work after that on some days.

Sandholm invited all four players to his home for dinner Friday, a kind gesture the players good-naturedly figured had another purpose.

“I think they really want to find out how they can improve the bot,” Li said with a smile. “But I don’t think there’s too much we can share with them because we might be coming back some day.”