Efron's dice

Etymology
Invented by.

Proper noun

 * 1)  A set of four intransitive dice with faces numbered as follows: A: 4, 4, 4, 4, 0, 0; B: 3, 3, 3, 3, 3, 3; C: 6, 6, 2, 2, 2, 2; and D: 5, 5, 5, 1, 1, 1. They have unusual statistical properties.