The humans were given their chance and at the end of it all, the OpenAI Five stands triumphant and makes its mark in Dota 2 history. At the end of a four-day Arena, the OpenAI Five recorded total wins of 7,215 against 42 loses, for a winrate at 99.4%.
The Arena matches followed the exhibition match where the Five beat out TI8 Champion OG 2-0. This is the first time that an AI worked as a team and defeated a human team.
In the exhibition game, the Five made use of buybacks. In most human vs. human tournaments, buybacks are typically not used in the early stages of the game. However for the Five, buyback decision went in their favor as the AI team managed to keep the pressure on OG. In a statement made by OpenAI Chief Technology Officer Greg Brockman, AI using buybacks at such an early stage is not surprising as AI generally favors short-term gains unlike human-led teams that incorporate long-term planning in their decisions.
Registration for the Arena matches began April 13, with the actual matches being played between April 18 and April 21. Over that period, a total of 30,937 human players participated in the OpenAI challenge, with the total time the AI spent playing amounting to 10.7 years.
OpenAI Five spent the weekend playing with and against humans at Dota 2. Final win rate versus the Internet: 99.4%.
— OpenAI (@OpenAI) April 22, 2019
Competitive games won: 7,215
Competitive games lost: 42
Cooperative games played: 35,466
Total time spent playing: 10.7 years
Number of human players: 30,937
The performance of the Five was so impressive that it took 459 games before the human-led teams recorded a win. A total of 22 teams were able to get a win against the Five.
Of the 42 wins, humans won 27 times on the Radiant side and 15 on the Dire side. The highest team kill was 57, though the Five managed to get 68 team kills of its own. The longest game took one hour and 11 minutes, with the shortest at 26 minutes and 32 seconds.
It is worth noting that a player with username “ainodehna” led a team that recorded a 10 win streaks against the Five.
It should also be noted that while this is indeed a big leap for AI, the conditions arguably favored the AI. For example, the picks were limited to 17 heroes since these are the heroes that are supported so far. Bans were not allowed as well. Additional limitations include illusion runes not spawning and not being able to buy the recipe for certain items including Helm of the Dominator, Manta Style, and Necronomicon. Players could still buy the component items.
Even with these limitations, it goes to show that AI has indeed come a long way and many are excited with the prospect of seeing AI play the full game.
