AI beats Stratego's greatest player, ending one of the last human strongholds in board games

A team from Carnegie Mellon, NYU, Stanford, and MIT has built an AI that decisively beats the most successful Stratego player of all time. Training reportedly cost less than $8,000. In a paper published in Nature, researchers from Carnegie Mellon University, New York University, Stanford University, and MIT introduce Ataraxos, a Stratego AI. To the authors' knowledge, it's the first AI to reach superhuman performance in the board game.

In an official 20-game series, Ataraxos beat Dutch player Pim Niemeijer with 15 wins, one loss, and four draws. Niemeijer is considered the most decorated player in the game's history. He has won four world championships, 15 Dutch national titles, and two online world championships, and he spent more than 600 weeks at the top of the world rankings.

George Franka, the only player who has competed in every world championship since 1997, calls Niemeijer "the best Stratego player of all time." Stratego is an especially tough test for AI because both sides set up their 40 pieces face down. According to the paper, there are more than 10^33 possible setups.…