In case you missed it: the livestream from the Benchmark commentated by Purge⁠(opens in a new window) and ODPixel⁠(opens in a new window). Christy⁠(opens in a new window) and Greg⁠(opens in a new window) also both livetweeted the event.

The day began with a team of volunteers from the audience bravely playing the first public match against OpenAI Five. Five won within the first 14 minutes (an evenly-matched game generally takes 45 minutes).

We revealed a new OpenAI Five capability—the ability to draft⁠(opens in a new window). Drafting is considered an extremely challenging⁠(opens in a new window) part of Dota, since heroes interact with each other in complex ways.

In late June we added a win probability output to our neural network to introspect what OpenAI Five is predicting. When later considering drafting, we realized we could use this to evaluate the win probability of any draft: just look at the prediction on the first frame of a game with that lineup. In one week of implementation, we crafted a fake frame for each of the 11 million possible team matchups and wrote a tree search to find OpenAI Five’s optimal draft.