OpenAI Five won 99.4% of public games in its April 2019 online event.
The event, called OpenAI Five Arena, ran from April 18 to 21, 2019, and opened the Dota 2-playing system to the public. Across 7,257 competitive games involving 3,193 teams, the bots won 99.4% of the matches. Public reporting also recorded 42 losses, with many human teams abandoning games rather than playing to the end.
This online test followed OpenAI Five’s more famous live victory over OG, the reigning champions of The International 2018. On April 13, the bot team won a best-of-three series 2–0 in San Francisco, becoming the first AI system to defeat reigning esports world champions in a live match.
The figure describes OpenAI Five’s win rate, not the percentage of individual players defeated and not a claim that humans never won. A small number of strong teams found exploitable strategies, but the overall result showed how powerful the system had become in coordinated five-player Dota 2 play.