India, July 12 -- Facebook Inc. doesn't just own the world's largest social network -- it may also own the world's best poker player.

A new artificial intelligence program the company built with Carnegie Mellon University called Pluribus recently beat five poker professionals in a six-player Texas Hold'em tournament. After 10,000 hands, the system averaged profits of about $1,000 per hour using $1 chips, a "decisive margin of victory," according to a Facebook blog post.

AI has been besting humans at poker for a couple of years, but previous programs could compete with just a single player at a time. Given the complexities that come with poker, including techniques like bluffing, beating five humans in a single game is a significant mile...