At the 1968 Mexico City Olympics, the thin air at high altitude has often been cited as the major factor in a number of world-record efforts, especially that of American long jumper Bob Beamon, who broke the previous record by nearly two feet. But Beamon and other athletes probably benefited from maximum allowable tail winds of 2 meters per second. Author David Wallechinsky refers to the “unusual method” the Mexicans used to measure this speed, which oddly (suspiciously perhaps) was exactly 2.0 m.p.s. for several of the world record efforts. The wind-speed limit only applies in events that take place in one direction, not for races around the track, for example.