their actions do not deviate significantly from the prediction of a Nash equilibrium. In tennis serve-and-return plays, the situation is similar. It was found that the win rates are consistent with the minimax hypothesis, but the players' choices are not random: even professional tennis players are not good at randomizing, and switch their actions too often. See also Odds and evens - a game with the same strategic structure, that is played with fingers instead of coins. Rock paper scissors - a similar game in which each player has three strategies instead of two. Parity game - an unrelated (and much more complicated) two-player logic game, played on a colored graph. References Non-cooperative games