[adamrezich]

Chess is a poor example because it's a turn-based game whereas Dota is real-time and incredibly fast-paced. Visually parsing a chessboard to know which piece is which is trivial, and also you have all the time in the world to do it (between turns). In Dota things happen so quickly, particle effects pop off all over the place, and through all of it, you have to constantly manually re-place your camera in the optimal position.

In chess, both players always have perfect information about the game-state, and this is far from the case in Dota. OpenAI does account for fog of war, so it's not COMPLETELY omniscient, but it is still more omniscient than human players ever have the ability to be, without having to fiddle with the camera etc.