A funny thing happened a few months ago: Despite the dozens of other TV shows I needed to catch up on, I decided to watch all of CBS’ new series SEAL Team. Alright, maybe it wasn’t funny ha-ha, but it was the type of funny that comes with procrastinating, at least when writing about television is your profession. Before that moment, I’d considered watching SEAL Team simply because of the cast (including The Originals’ Daniel Gillies, even though the trailer made clear his character was killed off early in the pilot). But since I’m not invested in this particular subgenre—especially after the failed military series Brave (NBC) and Valor (The CW)—and wasn’t eager to add another dark, heavy TV show to my queue, I didn’t expect to stick with the series for long.

Here’s the thing: I ended up kind of loving SEAL Team. At first, I was only really hooked by one aspect of the show: Dita the Hair Missile, who plays Bravo Team K9 officer Cerberus on the show. After seven or eight episodes, I was finally able to see that the series is about something—how crushing this heroic work can be, on physical, mental, and emotional levels, and how talking through issues is useful, which is basically the opposite of what you’d expect from the series. By the end of the season, I genuinely cared about every member of Bravo Team’s issues, whether it was PTSD, their physical health, or hoping their significant other didn’t forget about them during their deployment. More lived-in and confident than most early season shows, SEAL Team even does a good job of making you care about peripheral characters, perhaps because it has so much ground to cover in both its homefront and deployment segments.

For all its other merits, though, SEAL Team works on the strength of David Boreanaz as the ensemble’s lead. In fact, since the fall of 1997—after recurring in the first season of Buffy the Vampire Slayer that same spring—David Boreanaz has been a series regular (and specifically, the male lead) of a television series every single year. There’s no “always” in television… unless you’re David Boreanaz. That’s 21 years of multi-season series, no less, none canceled after one season—which isn’t exactly “normal.” (Keep in mind, this is an actor with the surely-this-doesn’t-actually-happen backstory of being “discovered” while he was walking his dog.) In theory, this could be pure luck, but it’s clear that Boreanaz has been one of the driving factors, if not the driving factor, of the series in which he’s starred. In Buffy, it was as one half of the Buffy/Angel relationship; in Angel, it was as the titular champion and the leader of a crew in a fight toward redemption through helping the helpless; in Bones, he was one half of the fish-out-of-water procedural central will-they/won’t-they relationship. Now, on SEAL Team—in which his character, Jason Hayes, struggles as a husband, father, and Tier One SEAL Team chief—Boreanaz continues the pattern. He’s had a large footprint on television throughout his career.

Boreanaz has never been off TV long enough for anyone to miss him: His longest stretch between roles was between the end of Angel, in the spring of 2004, and the premiere of Bones, in the fall of 2005. Perhaps this is why, when it comes to actors from the Buffyverse (and the Whedonverse as a whole), Boreanaz has always been considered middle of the pack. If I had a dime for every time someone told me they never watched Angel because Angel’s was a “boring” character on Buffy, and/or because of Boreanaz’s lack of dynamism, I ‘d have enough money to skip writing this piece. There’s also the (related) argument that Boreanaz’s series have themselves been “middle of the pack,” but that’s an insult to Angel and Bones’ impact on their respective genres and on the medium as a whole, to say nothing of their longevity. SEAL Team is still in its infancy, but it’s off to a similarly strong start. Which raises the question: What is it about David Boreanaz that equals success in the (network) television world?

Boreanaz’s career trajectory is arguably comparable to another WB heartthrob, Joshua Jackson, who went from Dawson’s Creek to Fringe to The Affair—albeit with longer breaks than any Boreanaz has had—while sustaining a healthy career. (In fairness, Jackson’s body of work features more creative risks—not accounting for the eventual risks Bones took, such as a Sleepy Hollow crossover.) With Jackson, though, I can still, to this day, see him as a heartthrob to swoon over, the way I did when I was a kid (because of The Mighty Ducks, pre-Creek) and beyond; with Boreanaz, by contrast, the swooning stopped the older I got. Whether it’s because Pacey Witter was the perfect TV boyfriend—and there were plenty of reasons Angel was not—or a larger complex of reasons,watching a series starring Boreanaz, and even possibly watching it for Boreanaz, I can’t say it’s because of that childhood crush. The actor’s appearance, his former heartthrob status, honestly isn’t and can’t be the only explanation for his long and prolific career.

As someone who prefers Angel to Buffy—a controversial opinion, I know—and not just because of Boreanaz, I’ve thought a lot about Boreanaz as a leading man. One of Angel’s best qualities—and one it needed in order to sustain itself as long as it did—was that it showcased multiple facets of Angel’s personality. Not just the brooding loner who had to atone for his sins (which the show found a way to tackle and to poke fun at), but also the vain version of him, the uncool version, the old man version, even the literal dad version. Boreanaz clearly relished the moments he could play these other Angels, and it ultimately showcased that he could bring more to the table as an actor. (There’s also the part where Angelus, in Angel, is basically Boreanaz’s real-life personality turned up to 11, as opposed to the more calculating Angelus of Buffy). But even such skill—which you hope the lead of his own series has—isn’t enough to explain the career longevity, right?

Possibly, Boreanaz wants it and goes after it more than his peers, though that doesn’t account for the audience’s reception: Plenty of talented, hungry actors don’t have the same success rate that he does, especially in an era where high ratings are hard to come by. Perhaps the most impressive part of Boreanaz’s career has been his upward progress in terms of his network’s size—from The WB, to FOX (where Bones was on the bubble for most of its 12 seasons), to CBS: What he brings to the table as an actor might be comparable to Eric Dane on TNT (The Last Ship) or Josh Holloway on the USA Network (Colony), but that foorprint of his? It’s steadily grown throughout his time on TV. He’s such a major presence in the business—without seeming to be a major presence in the business—that there’s even an episode of Bojack Horseman dedicated to clowning on him.

Boreanaz comes across as a likable actor who you never think is half-assing anything. You never get the impression he has anything less than respect for his characters, though he’s more than willing to move on once his work on a series is said and done. Even if I have to tap out of a Boreanaz vehicle eventually—which I had to do with Bones, after committing a respectable seven years of my life to it—his presence is enough to attract my interest for an early look. Who woulda thunk it? Seriously, would you? Because while you may know the story about Joss Whedon seeing that they could build a show around Boreanaz after his work in Season Two of Buffy, there’s a difference between making a (successful) spin-off for an actor with an established character (for five seasons) and an actor making his half of a will-they/won’t-they procedural work (for 12 seasons), and a further difference between that and holding down the fort as the lead of an ensemble drama on CBS.

It feels like a cop-out to just say Boreanaz has “it” and be done with this, especially when that calls into question all the other actors in this business who must not have enough “it” to be working as steadily as he is. I’d be lying if I said I didn’t consider making a Homeland-esque evidence board to truly track Boreanaz’s career path as a leading man—which I would then condense into a file called “I Don’t Know How He Does It,” especially since I haven’t even addressed the Dido of it all.

The truth is, over the span of two decades and counting, TV has become David Boreanaz’s playground, he one of its most steadfast features. Perhaps that is the fundamental reason for his longevity: In an industry defined by evolution, by cycles of what does and does not work, there’s something to having at least one constant. And Boreanaz has been game enough to fill that “constant” role, even when his characters are drastically different from one another. His familiarity creates a sense of consistency, and while the series built around Boreanaz may develop merits beyond his presence, that presence opens the door to a show, inviting viewers in. After three seasons of Buffy, five of Angel, 12 of Bones, he has already proven himself several times over, which is why I shouldn’t have doubted SEAL Team. Because he is that ultimate television comfort: the known quantity.

Season Two of SEAL Team premieres tonight at 9 p.m. on CBS.

Despite her mother’s wishes, LaToya Ferguson is a writer living in Los Angeles. If you want to talk The WB’s image campaigns circa 1999-2003, LaToya’s your girl. Her writing has been featured in The A.V. Club, Indiewire, Entertainment Weekly, Complex, Consequence of Sound, and Flavorwire, among other publications. You can find her tweets about TV shows, movies, and music you completely forgot about @lafergs.