Professional poker player Jason Les plays against "Libratus," a computer program, during the Brains vs. Artificial Intelligence rematch Wednesday at Rivers Casino on the North Shore. The computer program developed at CMU by professor Thomas Sandholm, right, and his student Noam Brown uses algorithms to study the rules of poker and create its own strategy.
From left, Bjorn Li, Jason Les, Doug Polk and Dong Kim, the four human players that defeated Carnegie Mellon University's computer poker program Claudico, stand in front of the tournament's leaderboard in Rivers Casino in May 2015.
By Gary Rotstein / Pittsburgh Post-Gazette
The bad news for humankind: Unlike the first time a Carnegie Mellon University card-playing computer went up against four of the best poker players in the world, the participant driven by algorithms instead of brain, heart, blood and soul is ahead.
The good news: With only 2,840 Texas Hold ’em hands played Wednesday out of the 120,000 that are planned over 20 days, no one — hard-wired or not — is pronouncing any conclusions from the opening of the competition at the Rivers Casino that is again being monitored worldwide.
There’s still a lot to be determined from “Brains Vs. Artificial Intelligence: Upping the Ante,” including its outcome. The early success of Libratus (Latin for “balanced” or “powerful”), compared with its predecessor that lost a similar contest against four pros in May 2015, could be just the luck of the cards on one day.
WATCH part of Wednesday’s matchup below:
Or, as is hoped by CMU computer science professor Tuomas Sandholm — the brains behind Libratus’ artificially intelligent brain — it could be far more meaningful. Mr. Sandholm was all smiles at 7 p.m. in the casino’s poker room even as Daniel McAulay of Scotland won the last hand of the day, using a jack in his hand to match a jack on the board and force the computer to fold against him.
“I’m always smiling, but clearly there’s a good reason to smile this time,” Mr. Sandholm said. “Last time the first day was our worst day of all.”
Mr. McAulay was one of four high-level professionals competing separately and simultaneously against Libratus in one-on-one competition known as the heads-up, no-limit version of Texas Hold ’em.
They played hands almost constantly over eight hours for pretend money that measured success. Mr. McAuley did the best of any human, leading by $4,938, and Jimmy Chou beat the computer for $2,290. Meanwhile, pro Dong Kim lost by $60,305 and Jason Les by $21,411.
Interestingly, Mr, Les and Mr. Kim had both played the prior CMU computer, Claudico, while the two flesh-and-blood leaders on the first day were new to a version of competition was followed by viewers from 62 different countries on the Rivers Casino website Wednesday.
Before the competition started, the pros said they figured to be facing an upgrade over Claudico, which was deemed to have some unusual and unwise strategies. The humanoids hoped to still come out ahead, however, in a game that involves gut-level decision-making and bluffing as well as high-level math and probability deduction.
“I expected it to play better, and it is playing better,” Mr. Les acknowledged when concluding play on two computer screens that were facing him. “It’s playing a more reasonable game, but it’s a small sample. It’s just too early to tell” whether Libratus will win the full competition instead of one day.
Two differences the humans noticed: Libratus was making a wide but solid variation in its betting habits that made it hard for them to get a good read on the hands it was holding. And, Libratus was playing more deliberately than its predecessor, at a sometimes frustrating pace — occasionally taking 10 seconds or more to make a decision the humans are used to doing instantaneously — which made them wonder whether it will be feasible to complete the 120,000 hands in 20 days.
“It’s thinking,” was Mr. Sandholm’s explanation when it was suggested to him that computers are supposed to get faster, not slower. “It’s thinking much faster, but it’s also thinking much more.”
The pros, none of them Pittsburghers, are in competition against one another as well as Libratus. They are to divvy up $200,000 among them for their participation, with different shares distributed based on how well they do.
They were all in cahoots Wednesday evening, however, headed out together to strategize over what they might do differently today. At their Downtown hotel, they planned to get out their laptops and a computer analysis of the first day’s results to assist them.
After all, they’re only human.
Gary Rotstein: firstname.lastname@example.org or 412-263-1255.
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