3. The original plastic helmets had a shattering problem.
In 1940, John T. Riddell and his son John T. Riddell Jr. (yes, they founded the Riddell company) ushered out the leather era when they began producing plastic helmets. Soon after, the Riddell duo also invented the chin strap.
The helmets, though, were susceptible to shattering upon impact; hence the NFL's apprehension in adopting them right away. Riddell responded by designing a helmet in the shape of a teardrop, which allowed a blow to slide to one side or the other instead of absorbing it head on.
Once all the construction issues were sorted out, the NFL made the plastic helmet legal in 1949.
4. The Cleveland Browns coach invented the single-bar face mask in the middle of a game.
The face mask debuted around the mid-1930s when Vern McMillan, the owner of a sporting goods store in Indiana, crafted a rubber-covered wire mask. And during a game in 1953, Browns coach Paul Brown conceived the single-bar face mask after his quarterback's mouth was torn open. Brown needed a way to keep him on the field for a victory.
Former Detroit Lion, Garo Yepremian, was the last NFL player to play without a face mask. “’I would wake up every morning with blood in my mouth," Yepremian told ESPN in 2009. "I learned my lesson."