Ataraxos reaches superhuman Stratego performance with a more compute-efficient hidden-information method

What changed

A Nature paper reports Ataraxos, which combines self-play reinforcement learning, a belief model and test-time search for games with large amounts of hidden information. In a 20-game match it recorded 15 wins, one loss and four draws against decorated Stratego champion Pim Niemeijer, while the team says training cost only a few thousand dollars. Related methods also performed strongly in Barrage Stratego, Hanabi and dou dizhu; real-world transfer remains a research goal rather than a demonstrated result.