 There is also the question, for Stalnaker, of the uniqueness assumption—that there is a unique closest antecedent-world. Stalnaker (1981, pp. 87–91) discusses this, and proposes to use the machinery of supervaluations when there is no unique nearest world: the conditional is true iff true whichever of the candidates for nearest the selection function selects, false iff false for all such selections, otherwise it is indeterminate—neither true nor false. As the uniqueness assumption often fails, a great many conditionals will just get the verdict indeterminate. For instance, I am considering whether, (*) if I pick a red ball, it will have a black spot. 90% of the red balls have black spots. Merely to be told that (*) is indeterminate, is less helpful than being told it is 90% likely.