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January 12, 2017

Poker Play Begins in "Brains Vs. AI: Upping the Ante"

Pros will play 120,000 hands against Carnegie Mellon artificial intelligence

By Byron Spice


Play began Jan. 11 for "Brains Vs. Artificial Intelligence: Upping the Ante," a competition at Rivers Casino in Pittsburgh that pits a Carnegie Mellon University artificial intelligence called Libratus against four of the world's best professional poker players.

During the 20-day event, Libratus and the pros - Jason Les, Dong Kim, Daniel McAulay and Jimmy Chou - will play a total of 120,000 hands of Heads-Up No-Limit Texas Hold'em. The pros will split a prize purse of $200,000, while the AI and its creators - Professor Tuomas Sandholm and Ph.D. student Noam Brown - look to prove that AI can best the top high-stake players of the game.

"A lot of people throughout the AI community are watching this event carefully," said Andrew Moore, dean of Carnegie Mellon's School of Computer Science. He said beating some of the top players in the game would be a significant achievement for AI and will only be possible if Libratus can successfully bluff and otherwise mislead its human opponents.

Moore noted that the ability to outperform the best human players at an imperfect information game such as poker could lead to a host of new applications for AI. For example, he said negotiating the best price for a new car might someday be a task that people can assign to their smartphone.

But the game they are playing in Brains Vs. AI is two-player Texas Hold'em with no restrictions on bet size, an incredibly complex game that has proven elusive to solution by AI, said Sandholm, a professor of computer science. A previous CMU AI, called Claudico, was out-pointed in the first Brains Vs. AI competition in 2015. He noted that international betting sites consider Libratus a definite underdog in this contest, with odds varying between 4-to-1 and 5-to-1 against the AI.

"I'm really delighted that we got four of the top Heads-Up No-Limit Texas Hold'em specialists in the world here today," Sandholm said, making the event the ultimate test of the AI.

AIs developed by Sandholm and Brown have won the last two Annual Computer Poker Competitions, in which pokerbots play each other. Libratus represents a two-generation leap ahead from Claudico, the AI that competed in the 2015 Brains Vs. AI.

"I don't know what to expect," said Les, one of the poker pros and a veteran of the 2015 contest, comparing the new Libratus to a player who has been practicing the game in Antarctica for years and is only now beginning to play others. He said he and his fellow players consider Brains Vs. AI to be part of an important research effort.

"If we're going to test this system, we really want to push it to the absolute limit," Les said.

Sandholm noted that the Libratus AI is not specifically a poker program. Its algorithm could be applied to any number of situations that involve incomplete and misleading information, such as business negotiations, military strategy, cybersecurity and even medical treatment design.

Libratus developed its knowledge of the game and its strategy by analyzing the rules of the game, not by trying to copy the play of humans. The AI calculated its poker strategy using about 15 million core hours of computation on the Pittsburgh Supercomputing Center's Bridges computer. Ralph Roskies, scientific director of the PSC, said this use of Bridges already has generated 2 1/2 petabytes of data.

To ensure  the outcome of the competition is not due to luck, the four pros will be paired to play duplicate matches - Player A in each pair will receive the same cards as the computer receives against Player B, and vice versa. One of the players in each of these pairs will play on the floor of the casino, while his counterpart will be isolated in a separate room.

For this second installment of Brains Vs. AI, the pros have agreed to increase the number of hands to improve the chance of reaching statistical significance, that is, ruling out with high confidence the possibility that either the humans or the computer win by just getting lucky. To do so, the pros will play more days and will "two-table," playing two hands simultaneously.

Play will begin at 11 a.m. each day at Rivers Casino and end around 7 p.m. The public is welcome to observe game play, which will be in Rivers' Poker Room. Libratus' games also will be streamed via Twitch. Aggregate scores will be posted each evening on the competition website.

Brains Vs. AI is sponsored by GreatPoint Ventures, Avenue4Analytics, TNG Technology Consulting GmbH, the journal Artificial Intelligence, Intel and Optimized Markets, Inc. Carnegie Mellon's School of Computer Science has partnered with Rivers Casino, the Pittsburgh Supercomputing Center (PSC) through a peer-reviewed XSEDE allocation, and Sandholm's Electronic Marketplaces Laboratory for this event.