MIT and CMU's Ataraxos AI becomes the new Stratego champion

[Y2J_WCW]

For a lighter AI story, researchers from MIT, Carnegie Mellon, NYU and Stanford have built an AI called Ataraxos that has become the best Stratego player in the world. The name comes from Greek and roughly means unbothered or free from anxiety. That turns out to be a fitting description of how it plays

Stratego is a tough game for AI because it involves hidden information. You cannot see your opponent's pieces, so you have to guess, bluff and manage risk. Ataraxos combines self play reinforcement learning to build a strong base strategy with decision time planning, using a generative model that estimates where the opponent's pieces probably are and refines its moves on the fly. Unlike chess, there is no perfect information to calculate from. Good players rely on bluffing and reading their opponent

The results are impressive. It beat the world's strongest Stratego player by a record 15 wins, 1 loss and 4 draws, and went 39-2 against top players at the Stratego world championship. It also reached superhuman level in other hidden information games, including Barrage Stratego, Hanabi and the Chinese card game Dou dizhu. That is a dominant record by any standard

The efficiency is just as notable. It used less than one hundredth of the training examples of DeepMind's DeepNash and less than one thirtieth of the self play games, at a much lower computing cost. Senior author Gabriele Farina said it is good at calculating risk in a way humans are not, adding that a human might panic when their most valuable piece is exposed, but the bot stays composed. Calm under pressure is a fair description of most good poker players too

I love stories like this because they show AI progress in a way that is easy to understand. Does anyone here play Stratego? And would you want to play against something that never panics?

This game-playing AI is the new champ at Strategonews.mit.edu