Watch humans take on a computer in a rematch of poker at Rivers Casino

Artificial Intelligence: Upping the Ante," a poker-playing computer and four of the best human poker players kicked off a rematch Wednesday at Rivers Casino. After a group of humans narrowly defeated a computer nearly two years ago, Jason Les, Dong Kim, Daniel McAulay and Jimmy Chou began play -- 8 hours on each of 20 straight days of 120,000 total hands (30,000 hands per player) -- Wednesday against the computer to see which of the four players gets the largest share of the $200,000 pot. They are matched against Libratus, the latest in CMU computer scientist Tuomas Sandholm's decade-long project to build a computer program that can learn and think its way to regularly beating humans in poker. In the previous matchup in May 2015, the humans beat a Libratus predecessor, Claudico. "It is important to all of us to give humans the best showing possible," Mr. Les told the Post-Gazette earlier this month. "The day is coming when computers will win.