Before sports referees donned the zebra stripes we know so well today, many showed up to games in some variation of this spiffy ensemble: white dress shirt and slacks, black bow tie, and white flat cap.

The uniform made officials seem official, but it wasn’t quite distinct enough to set them apart from the players during fast-paced gameplay. When one of the teams was also wearing white, things could get confusing. An Eastern Michigan University (EMU) student named Lloyd W. Olds experienced this issue firsthand while officiating high school basketball games in 1914. “The referee often looked very much like a player, so the lads often threw the ball to me or bounced it off my head,” he later recalled.

By 1920, Olds had started refereeing football in the area, too. After a quarterback from a white-clad team accidentally passed him the ball during one game, Olds finally decided he was long overdue for a costume change. He collaborated with an Ann Arbor sports shop owner named George Moe on a knit shirt with black and white vertical stripes, which he wore for the first time in 1921. It wasn’t an immediate success; according to The New York Times, fans actually booed him from the stands. “I took plenty of ribbing when I first appeared in it,” Olds said, “but the idea caught on among both basketball and football officials.”

Olds went on to become something of an athletic legend at Eastern Michigan University (known as the Michigan State Normal College until the late 1950s). He coached the university’s track and cross-country teams for 25 years, served as an assistant track coach for the U.S. Olympic team in 1932 and 1936, and developed EMU’s intramural program into a vibrant part of campus life.

But his farthest-reaching accomplishment is, without a doubt, the sartorial innovation that has kept officials from being mistaken for open teammates for 100 years and counting. Black and white stripes are now worn by referees in football, basketball, hockey, lacrosse, wrestling, and more.

[h/t The New York Times]