Can You Beat This Virtually Unbeatable Poker Algorithm? 

By Sarah Zhang on at

The challenge is on. Computer scientists say they've created an algorithm that has essentially solved a version of Texas Hold 'Em poker, and it's guaranteed to beat every single puny human competitor in the long run. Don't believe it? Why, you can play against the program yourself.

Cepheus, as the program is called, plays a virtually perfect game of heads-up limit Hold 'Em. The variant is like the popular Texas Hold 'Em, except there are only two players and a fixed number of bet sizes and raises. That still leaves 3.16 × 1017 states in the game.

The sheer feat of a program that's essentially solved a poker game has computer scientists in a tizzy. Unlike other games that have been completely solved such as draughts or Connect Four, where every past action is laid clear on the game board, poker is a game with imperfect information — namely, that you don't know your opponent's cards.

Cepheus is able to learn from its mistakes, and it achieved its current high status by playing billion and billions of hands against itself. It can even bluff. For game theorists, Cepheus could hold the key to modelling real-life situations like negotiations or auctions where information is imperfect.

But hey, you want to if you can beat it poker. It is of course possible to beat Cepheus in individual games, as poker involves an element of chance with each dealt hand. But in the long run, the computer will almost always come out ahead. There is a tiny margin of error, its creators say, but it is so small as to be practically negligible in our human lifetimes.

Say hello to Cepheus.

[At time of publish the site appears to be down, most likely due to high demand from people who think they can beat this thing. It's worth bookmarking and checking back. Ed.]

Top image: Kucher Serhii/shutterstock