Editing Jonathan Schaeffer (section)

==Poker: Polaris==
{{main|Polaris (poker bot)}}
Schaeffer is a member and, until 2004, leader of the computer poker research group at the [[University of Alberta]], which has developed several strong computer programs for playing [[Texas hold 'em]] poker.  The earliest and most general of these is Poki, which uses [[Monte Carlo simulation]] to choose actions during a game.  More recently, the group has focused on the two-player (Heads-Up) variant, and has developed a series of programs that approximate [[Nash equilibrium]] strategies for the game.  Several of these programs (such as Poki, SparBot and VexBot) are available in products such as Poker Academy from BioTools.

In July 2007, Schaeffer announced a competition between the group's newest program, [[Polaris (poker bot)|Polaris]], and two human professionals, [[Phil Laak]] and [[Ali Eslami]].  The competition was held at the 2007 [[Association for the Advancement of Artificial Intelligence]] (AAAI) conference, which also hosted an international competition between computer poker programs.  Out of four matches against the human professionals, Polaris won one, tied one, and lost twice; overall, the humans won the competition by a small margin.<ref name="UoA1">{{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 |url-status=dead |archiveurl=https://web.archive.org/web/20080523114124/http://www.expressnews.ualberta.ca/article.cfm?id=8611 |archivedate=May 23, 2008 }}</ref> In the computer competition, Polaris (playing under the name Hyperborean) won the Limit Hold'em event and came first in the No-Limit Hold'em event.<ref name="UoA2">{{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 }}{{dead link|date=November 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>  In 2008, an updated version of Polaris defeated a team of human professionals in the Second Man-Machine Poker Competition.<ref>{{Cite web |title=The Second Man-Machine Poker Competition |url=http://webdocs.cs.ualberta.ca/~games/poker/man-machine/ |access-date=2023-12-04 |website=webdocs.cs.ualberta.ca |archive-date=2023-11-15 |archive-url=https://web.archive.org/web/20231115040351/https://webdocs.cs.ualberta.ca/~games/poker/man-machine/ |url-status=live }}</ref>