NEW YORK—On network TV, one name reigns supreme. Not Les (as in Moonves) or Sheldon (as in Young)—no, the name that’s taken over TV and is emblazoned on city buses and half-torn-down posters on subway walls is much less assuming. Have you met Kevin?

On Tuesday night, Kevin was the star of ABC’s Kevin (Probably) Saves the World, a program about a man (Jason Ritter) who inherits a guardian angel and is set on a path toward righteousness after a meteor lands in his yard. One night earlier, Kevin (Kevin James) was still recovering from the off-screen death of his wife by palling around with his former TV wife in Kevin Can Wait. And there recently was a Kevin before those Kevins—the unlucky-in-love protagonist of ABC Family’s 2015 show Kevin From Work. (Also, let us not forget the much younger Kevin from the 2011 film, We Need to Talk About Kevin.)

Of the scripted shows on the four major networks that currently include a first name in the title—Kevin Can Wait, Young Sheldon, Kevin (Probably) Saves the World, Bob’s Burgers, Will & Grace, and Marlon—33 percent of them feature a Kevin. Not since the Charlie Boom in the 1980s (Charlie’s Angels, Charles in Charge, Charlie & Co.) has one name earned such a large market share. According to government records, Kevin was the 89th most popular male baby name in the United States in 2016—behind names like Wyatt, Hudson, and Colton. So with popularity a nonfactor, the question must be asked: Why? What is it about the name Kevin that makes it so agreeable to networks and their audiences? For what reason have we been doomed to the episodic lives of so many Kevins?

Kevin, the anglicized version of the Irish name Caoimhín, was rarely given until the mid-20th century. The name didn’t break into the top 100 baby names until 1949, and from there gradually gained popularity until peaking at no. 11 in 1963; for the next four decades, Kevin bobbed around in the late teens, 20s, and 30s before falling right off a cliff in the mid-aughts. These numbers mean something: first, that Kevin is a relic from the baby boomer era. (Kevin James, the Kevin from Kevin Can Wait, was born in 1965.) Maybe it serves as a comfort to a section of the viewing public; a section that is important to networks like CBS and ABC, which in 2015 had median viewer ages of 59.9 and 55.9, respectively. The numbers also show that while Kevin was somewhat popular at one time, it was never a Michael or a James. Instead, it’s a name that’s in a sweet spot between overfamiliarity and obscurity.

“It’s popular, but not too popular,” says Kevin Clark, one of two Kevins on the Ringer staff. “Understood as a common name but [still] underutilized.” He may be right: Kevin may be just the right amount of normal, just the right amount of boring.

Mr. Clark says he’s OK with his name becoming a hallmark of network television—the only fictional Kevin he’s ever had beef with was Home Alone’s Kevin McCallister. “References were very, very common in my childhood, which was annoying,” he admits. (Interestingly enough, the name Kevin’s popularity surged all the way to no. 1 in Germany in 1991 after the release of Home Alone, and a study in 2015 concluded that European Kevins were being stereotyped as lower class.)

“I had never thought about it,” Kevin O’Connor, The Ringer’s second Kevin, says when I ask him about the proliferation of TV Kevins. After he did think about it, he too deduced that perhaps the utilization of the name was a tactic by writers aimed at a specific audience. What neither Kevin could explain was what it felt like to be a Kevin. I had hoped that by distilling Kevin-ness into a simple yet profound essence, I could then understand why television was opting for those vibes. But alas. “Nothing exactly comes to mind,” Mr. O’Connor says, before adding: “Only Kevin James knows the true Kevin experience.”

Mr. James did not respond to my inquiries.