Despite the years of self play OpenAI Five has gone through, humans still manage to find and successfully exploit its weaknesses. Adapting to opponents remains an unsolved meta-problem.

Team Secret was just plain better than Five — even weak points were scenarios seen during self-play. Was really amazing to watch Secret in action. Note that Five does not learn online — it's more like a creature of pure instinct. More like an insect than a human in that way.