University of Alberta researchers are betting that their poker-playing computer program will beat two of the sharpest human professional players in the world, and they're not bluffing — yet.

The developers of the Polaris program have challenged Phil (the Unabomber) Laak and Ali Eslami to 2,000 hands of Texas hold 'em. The $50,000 man-versus-machine poker match will not only be fun, but will help test advances in artificial intelligence, said Jonathan Schaeffer, leader of the computer science team that created Polaris.

"We have developed a format that has helped us factor out luck and make it into a scientific experiment to determine how good humans are relative to the best program in the world," Schaeffer said.

"The goal is to eventually produce a poker program that is stronger than all human players."

Texas hold 'em is considered the most popular variant of poker played today, thanks in part to plenty of exposure on television and the internet.

Players are dealt two cards face down and then share a series of five community cards to form the best hand. Some games feature unlimited betting.

A combination of styles

The match will be played on July 23 and 24 in conjunction with the Association for the Advancement of Artificial Intelligence Conference in Vancouver.

Polaris is actually a number of different computer programs with different characteristics.

One is very aggressive, but doesn't take into account the playing style of opponents.

Another program assesses the strengths and weaknesses of other players and adjusts its style accordingly.

All of the programs areadept at one of the most interesting aspects of playing poker — bluffing.

"There is a mathematically optimal rate at which you should bluff. Computers can calculate that. Humans don't understand the mathematics of poker. If they bluff too much, you can exploit them and win money," Schaeffer said.

But the mechanical card sharks do have a weak point.

Programs that don'tadapt can be exploited if human opponents are skilful and savvy enough to pick up on the computer's playing style.

Schaeffer is also mindful of the chess analogy, noting the 1997 match between IBM's Deep Blue program and Gary Kasparov, the world chess champion at the time. The computer program won that multi-game match.

'If that is a bluff, it's over for humanity'

But Laak and Eslami won't know which program they will be playing against this summer, and the researchers will be able to shift to a different program if the computer's game starts to fold.

Laak, who wears his trademark hoodie and sunglasses whenever he sits at the card table, is a veteran of the poker circuit and sometimes works as a television commentator.

With a degree in mechanical engineering, Laak has tangled with computer poker programs before.

Facing a check-raise from a computer during a match in 2005 he once exclaimed, "If that is a bluff, it's over for humanity," and promptly folded. It was a bluff.

Laak selected Eslami, a professional poker player who is also a computer consultant, to be his teammate in the July match.

Together they will play against the computer. Each match will consist of 500 hands played in four sessions over two days.