For you youngsters, in the 1970s (during the first running boom) the coventional wisdom was that all male athletes including runners should wear athletic supporters, jock straps, or risk injuring their willies.
A Jones Counter is the only acceptable device for certifying the distance of a race course in the US. Now that personal GPS units are common I have heard runners say at certified races that it was well short or too long because their Garmin said so.