The work that rule enforcement officials do in sports is more difficult to evaluate than popular imagination would suggest. Officials are not expected to call every infraction of the rules; in fact, they are expected not to. It is not the correctness of a call (or non-call) that is at issue, therefore, but the fairness of a pattern of discretionary calls. Using the work of National Hockey League linesmen and referees as examples, this article describes three methods used by professional sports leagues to produce fairness on the part of officials and, more importantly, to prove that fairness has been accomplished. I have characterized these methods as the procedural production of consistency, the substantive production of consistency, and the supervision of officials’ work. The failure of these methods to produce compelling and objective evidence of fairness supplies a persistent and essentially unresolvable problem for those who man the social control apparatus. Ironically, the tension that this problem generates, and the attention therefore paid to the issue of fairness, is probably the best guarantee that fairness is produced.