I can't make any sense out of the xkcd figures. How do you mentally navigate them, where do they take you, and what do you know at the end?
It's a visual representation of the most optimal tic-tac-toe strategy based on a given game state. Assume you're playing as X, who goes first. The largest X in the whole figure is in the top-left, indicating that that's X's optimal move. Now, let's say O decided to play in the top-middle square. You would "zoom in" on that ninth of the board; the black X and O represent the fact that this is the current state of the game. There is now a large red X in the middle, so that's where you should play your next move. Repeat until the game is over.
Thanks, I follow now. I guess I don't have the tic-tac-toe mind.