The bot team, called OpenAI Five, has certainly had enough practice to hold its own: it has been playing 180 years' worth of games against itself every day, picking up the intricacies of the MOBA along the way.
The humans did eventually manage to grab game three from the bots but the damage was done.
Watch OpenAI Five dominate Team Human in the video below. If the the OpenAI Five are victorious, they not only join the pantheon of machines that have publicly beaten humans at games (Deep Blue, Watson, AlphaGo), but will have done so in a game that balances several real-time interactions at once.
Past year a single OpenAI Dota 2 bot made a surprise appearance at Valve's International Dota 2 tournament held in Seattle and had a decisive victory playing against Danylo "Dendi" Ishutin, who having been beaten in the first two rounds declined to play the third.
In the first match, the AI steamrolled the humans in just 21 minutes. In this situation, skill didn't really come into play as much, as the well-crafted lineup from the humans simply out-matched the poorly picked OpenAI, and it was the only victory that any group managed to take against them. The second game saw the humans grab a tower from the OpenAI bots but ultimately the humans lost a second game. This was an implemented as an extension of adding a win probability output to the neural network to introspect what OpenAI Five is predicting.
The only possible bright point was that OpenAI let the final match composition be chosen by the audience, meaning the audience stepped in to vote for which heroes OpenAI would control. This was a best-of-three against a team of 99.95th percentile Dota players: Blitz, Cap, Fogged, Merlini, and MoonMeander - four of whom had played Dota professionally - in front of a live audience and 100,000 concurrent livestream viewers.
Dota 2 is available now for PC, Mac, and Linux. The Open AI bot went on to best other notable players including, SumaiL, and former world champion, Dendi.