Some humans have gotten very good at playing the video game Dota 2. It’s a complex game with over 100 different character types, an in-game economy, and an audience of spectators on Twitch.tv. Oh, and tournaments in which professional Dota 2 players have earned over $100M. And now the championship team has been crushed by an AI:
Within the simplified bounds of the game, OpenAI Five was an astounding triumph. One thing to look for in evaluating the performance of an AI system on a strategy game is whether it’s merely winning with what gamers call “micro” — the second-to-second positioning and attack skills where a computer’s reflexes are a huge advantage.
OpenAI Five did have good micro, but it also did well in ways that human players, now that they’ve seen it, may well choose to emulate — suggesting that it didn’t just succeed through superior reflexes. The commentators watching the game criticized OpenAI Five’s eagerness to buy back into the game when its heroes died, for example, but the tactic was borne out — maybe suggesting that human pros should be a bit more willing to pay to rejoin the field.
And OpenAI had a deeper strategic understanding of the board than the human commentators. When the commentators were asserting that the game looked evenly matched, OpenAI would declare that it perceived a 90 percent chance of victory. (It turns out that soberly announced probability estimates make for great trash talk, and these declarations frequently rattled their opponents OG). To us, the game may have seemed open, but to the computer, it was obviously nearly over.
AI triumphs against the world’s top pro team in strategy game Dota 2
Three points to note here:
- Rate of improvement. AI’s are improving at an astonishing rate. Chess fell, then Go, now very complex multi-player strategic games like Dota 2. It used to be that game-playing algorithms were customized for specific games and had little applicability to other domains. This is truly a revolution.
- Scale of computation. The scale of computation available to the AI’s matters a lot. OpenAI, the researchers behind this AI victory, improved on their previous performance by utilizing eight times more training compute. They trained this model on 45,000 years of Dota self-play over 10 realtime months. Good luck humans.
- Real-world applications. Dota 2 is a very complex game with many characters making independent real-time judgments as part of teams trying to take over each other’s bases while protecting their own. It’s a complex simulation of war. The real world is of course still more complex, but this is a domain in which the AI’s appear to do well. Defense departments around the world are paying attention.
Update: The OpenAI team let their AI play against regular Dota 2 players. Out of 7,257 matches, the AI’s won 7,215 (99.4%) and lost just 42.