John M. Talmadge, M.D.

A Blog Covering Many Topics

Part 1: Texas Holdem Poker, Human vs AI Computer


Fifteen years ago I, Dr. John Talmadge, became a serious poker player. I have a winning record at the poker table, and although I am (probably) not good enough to quit my day job, I have held my own with professionals in Las Vegas, and I finished in the top third of the field in the World Series of Poker Senior Event in 2009. Although I finished out of the money, I came in ahead of about 2000 other players in that event. In the years since, I have consulted with professional players on "the mental game," and I remain a serious student of Texas Holdem, the world's greatest card game.

Image of Brains vs. AI in Texas Holdem Poker

Now comes Aviva Rutkin, writing in New Scientist that human poker professionals are taking on artificial intelligence (and the strongest poker playing computer built to date), and they are playing for real money. Here's the story.

Computer scientists have already made some progress, at least with simpler forms of the game. But the version being played at the Pittsburgh tournament, called Heads Up No Limit Texas Hold 'em, is "a completely different beast", says pro player Vanessa Selbst. "There's much more human elements and game strategies to employ, so it's a much more complex game." What's more, there are no betting limits, so the computer also has to take into account how much players might stake on each game.

Competing in Pittsburgh is Claudico, a program created at Carnegie Mellon University. Claudico taught itself poker skills by playing trillions of games in search of some kind of optimal strategy. Whatever it has picked is pretty good: last year, Claudico beat all 13 other computer competitors at no-limit poker in the annual contest run by the Association for the Advancement of Artificial Intelligence.

Computers have a few edges over humans, says graduate student Noam Brown, part of the team behind Claudico. For example, a computer can switch randomly between various betting strategies, which may confuse human opponents.

On the other hand, Claudico is slow to pick up on and adapt to people's playing styles – something that many pro players do with ease. "One of our big concerns is that the human will be able to identify weaknesses that Claudico has and exploit them," says Brown.

Because Claudico taught itself to play, even the team that built it don't quite know how it picks its moves. "We're putting our faith in Claudico. It knows much better than we do what it's doing."

Algorithms like those used to play poker could be valuable for other kinds of problems characterised by imperfect information. They could suggest optimal locations for military resources in a war, for example. Rival AIs could also be tasked to negotiate with each other over insurance rates or handle legal squabbles. "In society, sometimes you see one side getting screwed over because someone has more lawyers or more information or more resources at their disposal," says Brown. "Something like this can really level the playing field."

The winner of the poker tournament won't be crowned until the event ends on 7 May. Eric Jackson, a software engineer who creates poker bots as a hobby, is cautiously optimistic that Claudico can win. As we went to press, the pros and Claudico were neck and neck.

Even if AI triumphs, it won't mean programmers have conquered the game. "Beating humans decisively would be a landmark, but it wouldn't mean the end of work on poker," says Jackson. "We still don't know what the perfect strategy is."

The original article by Aviva Rutkin can be found online here.