Key-independent optimality is a property of some binary search tree data structures in computer scienceproposed by John Iacono.Suppose that key-value pairs are stored in a datastructure, and that the keys have no relation to their paired values. A data structure has **key-independent optimality** if, when randomly assigning the keys, the expected performance of the data structure is within a constant factor of the optimal data structure. Key-independent optimality is related to dynamic optimality.