Year Introduced: 1979
Sport: Hockey

Believe it or not, until 1979 NHL athletes weren't required to wear a helmet when they were playing. Seems crazy, we know, but, thankfully, league president John Ziegler rectified the situation in response to the numerous head injuries that players had been suffering over the years. We're glad that the league finally got around to solving that problem, but they might want to do the same with full face shields while they're at it. Duncan Keith's teeth would appreciate it.