Claudico is an artificial intelligence computer program designed to play no limit Texas hold 'em heads-up.
Claudico was designed by Carnegie Mellon professor Tuomas Sandholm and his graduate students. The name means "I limp" in Latin, a reference to limping into a hand without raising—a strategy the bot employs often. Rather than have a professional poker player attempt to explain his strategy to the programming team, Sandholm had the computer attempt to devise the best strategy on its own. The task was so complicated that it required a Pittsburgh Supercomputing Center Blacklight supercomputer with 16 terabytes of RAM to complete.
In explaining his motivation for designing the bot, Sandholm said, "Poker is now a benchmark for artificial intelligence research, just as chess once was. It's a game of exceeding complexity that requires a machine to make decisions based on incomplete and often misleading information, thanks to bluffing, slow play and other decoys".
Originally called Tartanian, a version of the program won a July 2014 tournament against other computer programs.
The improved successor of Claudico is called Libratus. Like Claudico, Libratus is designed to compete against top human players.
From April 24 to May 8, 2015, Claudico participated in an event at Rivers Casino in Pittsburgh, Pennsylvania. The bot faced each of four top human opponents—Dong Kim, Jason Les, Bjorn Li, and Doug Polk—in a series of heads-up matches. At the time, Polk was the world's number-one ranked heads-up player.
Each day featured two 750-hand matches over eight hours (plus breaks) against each of the humans, for a total of 20,000 hands per player over the course of 13 days (with one rest day in the middle). For each 750-hand set, the same hands were dealt to one human taking on Claudico on the main casino floor and another battling the computer in an isolation room, with the hole cards reversed. This was done to ensure that card luck was not a factor in the outcome. The 80,000-hand sample represented the largest-ever human–computer data set. Claudico was able to adjust to its opponent's strategy as the matches progressed, just as the humans could. The match winner was determined by the overall chip count after 80,000 hands; although individual results were kept for the four pros, they were competing as a single team. If the final chip count had been too close for the difference to be statistically meaningful, the match would be declared a draw.