In other words, by postulating the need for coordination of expectations, we seem to have a theoretical basis for something like the Nash axioms. What a theory like Nash’s needs is the premise that a solution exists; it is the observable phenomenon of tacit coordination that provides empirical evidence that (sometimes) rational expectations can be tacitly focused on a unique (and perhaps efficient) outcome, and that leads one to suppose that the same may be possible in a game that provides nothing but mathematical properties to work on. The Nash theory is vindication of this supposition—complete vindication if it dominates all competing mathematical solutions in terms of mathematical esthetics. The resulting focal point is limited to the universe of mathematics, however, which should not be equated with the universe of game theory.

DEFINE: Clarifies how focal points (tacit coordination) ground the Nash equilibrium concept, connecting experimental observation to abstract game theory.

Thomas C. Schelling, The Strategy of Conflict, loc. 669