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World-Class Poker Machine Unleashes 'Absolute Devastation' On Poker Pros

Bot Begins To Pull Away From Its Human Opponents


Though they had started to stage a comeback earlier in the week, the poker bot Libratus was able to soundly squash the upswing by its human opponents.

Going into Friday, the four heads-up no-limit poker pros were down a combined 460,000 against Carnegie Mellon University’s bot. Nearly 50,000 of the scheduled 120,000 hands had been played. The 20-day battle at Rivers Casino is set to end later this month.

The match had been brought back to nearly even just a few days ago, but the world-class artificial intelligence wasn’t going to relinquish its lead that easily.

“Absolute devastation for the human team across the board,” said Doug Polk, who isn’t playing this time around but was on the team that beat an earlier version of the bot in 2015. “The deficit is starting to look overwhelming.”

Computer Scientist Tuomas Sandholm And Poker Pro Jason LesThe 460,000 chips is 4,600 big blinds. Each hand begins with each player sitting with 200 big blinds, or 20,000 in chips. In 2015, the human team beat Claudico by 732,700 chips. Blinds were also 50-100 in that match.

However, computer scientists at Carnegie Mellon called it a “statistical tie.” It’s unclear if the current match would be deemed a tie if it ended right now, but the humans are on pace to finish down by about a million chips, which would presumably be considered a loss.

According to analysis from Polk, a big difference in the bot’s strategy this week has been its move toward raising 2.5 times the big blind on the button or folding, rather than limping some hands or min-raising. Polk said Libratus is superior to Claudico in this way. Computer scientists are allowed to alter the bot during the competition.

“In general in heads-up, min-raising [on the button] is kind of weak too because the big blind gets a great price,” Polk said. “It’s interesting that the computer decided to change its strategy on day 6, so I assume there was some human tinkering. I doubt that the computer decided over night that it wasn’t good to do anything other than 2.5 [times the big blind].”

Another thing working against the humans is the machine’s bet sizing on the river. Claudico would over-bet on the river for value and as bluffs, but Libratus does it better.

“The bot seems to really swing for the fences with both bluffs and value-bets,” Polk said. “It does them in a lot of spots that are pretty unconventional. Sometimes it does it in situations where it represents hands it would have had to slow-play on earlier streets, which isn’t as common in human matches. For example, if a flop was three spades, and it decides to bet the flop and check the turn, it will still have some massive over-bet jams on the river.”

Polk said the chances of the humans winning is now at under 10 percent.

“If they can’t figure out what’s going wrong and fix it, they are totally toast. It seems like the bot has gotten way better over the last two days.”

Tags: Poker Bot