OpenAI Five achieved a historic benchmark in artificial intelligence by defeating a team of elite Dota 2 players in a best-of-three series. The human opponents included professional players Blitz, Cap, Fogged, Merlini, and MoonMeander, who represent the 99.95th percentile of the player base. This event, livestreamed to 100,000 concurrent viewers, demonstrated the system's capacity to handle complex, real-time strategy.

A key development was the introduction of a 'drafting' capability, allowing the AI to evaluate 11 million possible team matchups using a win probability output. In the first two games, OpenAI Five predicted win probabilities of 95% and 76.2%, both of which it successfully secured. The dynamic shifted in the third game when the live audience adversarially selected the AI's heroes, resulting in a predicted 2.9% chance of victory.

Despite showing moments of resilience, the system ultimately lost, providing a transparent look at its limitations. The training for this iteration utilized 35 petaflop/s-days, building upon previous models. These results underscore a significant leap in AI's ability to navigate uncertainty and complex decision-making, setting the stage for a planned match against professional teams at The International.