[maaark]

I'm pretty sure OpenAI only plays the single simplest hero, mechanically. The other 115 would be varying degrees of "more difficult" to play competently.

Also, it only played mirror matches. If it had to play any hero against any hero, that's 3.393109e+190 possible matchups.

[bilkoo]

I don't think you need to learn all possible matchups to play any matchup, as a human would. You'd need to just learn how to play/counter each hero, plus some 2 or 3 hero combos (not all permutations), so on the order of a hundreds?

[wrsh07]

They've had some updates since then: https://blog.openai.com/openai-five-benchmark/

(Plus two shorter / more recent status updates)