In the early 1870s, catchers played bare faced. Balls routinely struck their eyes, broke their noses and knocked out their teeth. The danger increased when catchers, who had stood two dozen feet behind the batter, moved closer to the plate — an innovation, says the baseball historian Peter Morris, “that allowed the top pitchers to throw their best pitches.” The facial injuries finally decreased when a team from Harvard University rigged up a mask to protect its catchers that resembled a sturdy bird cage. The manager of the team, Frederick Thayer, patented the mask in 1878. Fans hated it. When the Harvard catcher James Tyng stepped onto the field with his head swaddled in steel and leather, he endured jeers from the crowd — people hooted at the mad dog who had to be “muzzled.” Editorial writers complained that the innovation detracted from the game. What was next — a lightning rod to save the catcher from freak storms? Would players limp around the bases with stovepipes on their legs for protection?

The debate inspired the sportswriter Henry Chadwick to muse on the true nature of courage. It was strange, he said, that catchers would “run the risk of broken cheek bones, dislocated jaws, a smashed nose or blackened eyes” simply because they were afraid of the “fools” in the crowd. According to Chadwick, a real man would not “tremble before the remarks of small boys.”

In the end, what really mattered was that the mask helped win games. “It changed how the game was played,” Morris says, because pitchers could throw fast and hard at a catcher who wore protection and not worry about causing an injury. “Even if your team didn’t have a great catcher, you could still have a chance to win.”

Thayer also played an aggressive game in the courtroom. When A. G. Spalding & Brothers advertised a $3 catcher’s mask for sale — without paying him any royalties — Thayer defended his patent and won. The original Harvard mask is in the National Baseball Hall of Fame.