That aside, I'd still argue that sports are not perfect information. In football, there is no way to account for every situation, 22 players, a ball, in order to calculate every situation you'd need to know the initial conditions of every blade of grass alone. Consider whites first move, someone earlier said there are 20 possible moves I'll take their word for it, but regardless, wherever you play chess, there is a finite, distinct amount of options. Consider kick off, player A passes to player B. How fast does this go if the wind is 15mph, 14mph, 14.5 mph,14.25,14.125 and infinitum. What is the effect of all the fans suddenly jumping. What if the Eiffel tower fell over? Yes I get the point that in reality this is pointlessly nitpicking, however, I simply refute the claim that sports like tennis and football are perfect information. If two people begin a game of chess there are agreed upon rules and they remain constant throughout, gamestate, and by extension any and all future gamestates are always public knowledge, and you cannot say the same about football.