Polaris (poker bot)

Polaris is a Texas hold 'em poker playing program developed by the computer poker research group at the University of Alberta, a project that has been under way for 16 years as of 2007.cite news|title=Chips are down as man beats poker machine |author=Dan Glaister |publisher=The Guardian |date=Friday July 27 2007 |url=http://www.guardian.co.uk/technology/2007/jul/27/gambling?gusrc=rss&feed=technology] Polaris is a composite program consisting of a number of bots, including HyperBorean07, the winner of the limit equilibrium series in the Association for the Advancement of Artificial Intelligence (AAAI) Computer Poker Competition. Polaris also contains a number of other fixed strategies, as well as an optional adaptive component which attempts to model opponent play and choose the best strategy against its opponent.cite news|title=Polaris drawing professionals to a stand-still |publisher=University of Alberta: Express News |date=July 20, 2007 |url=http://www.expressnews.ualberta.ca/article.cfm?id=8611] cite news|title=U of A researchers win computer poker title |publisher=University of Alberta: Express News |date=August 9, 2006 |author=Ryan Smith |url=http://www.expressnews.ualberta.ca/article.cfm?id=7789] Polaris required little computational power at match time, and was run on an Apple MacBook Pro laptop in the competition.cite news|title=Humans deal computer a loss in poker challenge |publisher=EETimes |date=July 26, 2007 |url=http://www.eetimes.com/news/semi/showArticle.jhtml?articleID=201201308 |author=R. Colin Johnson]

Play vs. professionals

On July 23-24, 2007, Polaris played against poker professionals Phil Laak and Ali Eslami at the Hyatt Regency Hotel in Vancouver, B.C. The competition consisted of 4 duplicate matches, with 500 hands per match. In each duplicate match, the same cards were dealt to both pairs of players, human and bot, but with the seating reversed. This meant that if Polaris had terrible hands in one half of the match against Phil, the other copy of Polaris would be getting great cards in the other half of the match against Ali. This was done to reduce variance, or "luck factor", as neither team could say they got the worse set of cards. The two players were in separate rooms to eliminate the chance of the audience revealing information about the hands, which would be especially problematic in a duplicate match.cite news|title=The First 'Man-Machine Poker Championship' Begins Tomorrow |publisher=Poker News |date=July 22, 2007 |author=Martin harris |url=http://www.pokernews.com/news/2007/7/man-machine-poker-championship-tomorrow.htm] Laak had previously played the Polaris predecessor Vexbot in 2005 in a prior tournament. Laak admitted to luck playing a part in his victory over Vexbot.cite news|title=Poker pros out of luck in battle with 'bot |date=June 11, 2007 |publisher=The Edmonton Journal |page=A2 |author=David Staples]

After roughly 16 hours of play over two days, Polaris tied the first round, won the second and lost the last two. One of the lost matches was against a learning variant which tried to switch between a few styles of play, while all of the remainder were against large, static, randomized sets of rules which approximate a pair of Nash equilibrium strategies. Laak and Eslami split 10,000 for the two wins, and 2,500 for the draw.cite news|title=How to beat a computer: lies, bluffing and taking risks are all on the cards |publisher=The Times Online |author=Chris Ayres |date=July 27, 2007 |url=http://news.google.com/news/url?sa=t&ct=us/18-2&fp=46aa545ac6f3b43a&ei=hCCqRqP8JI2-pALepICHAQ&url=http%3A//www.timesonline.co.uk/tol/news/tech_and_web/article2148364.ece&cid=1118314255]

On July 3-6, 2008, Polaris competed against six human professional poker players in the Second Man-Machine Poker Championship, held in Las Vegas at the 2008 Gaming Life Expo. Polaris defeated the human players with 3 wins, 2 losses and 1 tie. The winnings totaled $195k over the 6 matches (with $1k/$2k limits.)

ee also

*Association for the Advancement of Artificial Intelligence
*Computer poker players
*BluffBot

References

External links

* [http://www.cs.ualberta.ca/~games/poker/man-machine/ Official site] includes hand histories, a copy of the live blog that was updated throughout the matches, a gallery of photographs, video highlight reels, and post-match analysis.