Cheering on a team when it is doing well and winning big games does not demonstrate loyalty. Instead, it is doing so during the lows that proves devotion.

I grew up in suburbs of New York, the product of an extended family of Giants fans. Until high school, football and the Jets were an afterthought. I was always pondering questions like: Why does my best friend imitate Ken O’Brien by taking a snap and immediately falling on his back? Why does Grandma’s coffee table have a Sports Illustrated with Lawrence Taylor and Mark Gastineau on the cover that is telling me that the Jets are second banana in the Big Apple?

It wasn’t until my father and godfather took me to my first N.F.L. game — between the Kansas City Chiefs and the Jets at the Meadowlands on Nov. 29, 1992 — that a Jets-related question seemed truly urgent. It was: Is that player going to be O.K.? Like many around me that day, I was worried about Jets defensive lineman Dennis Byrd, who had collided with a teammate on an attempted sack and was not getting up. We were puzzled.

Minutes passed before Byrd was carried off the field on a stretcher. It wasn’t until later, on the ride home, that my dad and I heard that Byrd had injured his neck. It was feared that he would be paralyzed for life.

We prayed for Byrd while driving across the Tappan Zee Bridge. I tracked news of Byrd’s progress in the days and weeks that followed. Before I knew it, I had become a Jets fan, one who cheered when Byrd eventually walked again.

Tragedy marks the origins of superheroes and of fans. I’m a Jets fan because of a superhero named Dennis Byrd.