Casey Affleck is many things. A great actor is one of them; a household name is not. He’s certainly no Norman Reedus. Or Kristen Bell.

Saturday Night Live‘s decision to tap the Manchester By the Sea star to serve as the show’s final host of 2016 underscores a perplexing trend at the long-running late-night sketch show, one in which even marginally known movie stars are considered more viable hosting material than A-list TV talent.

Consider for a second that the following TV stars have never taken the Studio 8H stage: the aforementioned Reedus or Andrew Lincoln from the well-watched The Walking Dead, anyone representing the Modern Family cast (save for Sofia Vergara), Atlanta‘s Donald Glover, Master of None‘s Aziz Ansari, Orphan Black‘s Tatiana Maslany, Grey’s Anatomy‘s Ellen Pompeo or onetime leading man Patrick Dempsey, Gilmore Girls‘ Lauren Graham, Arrow‘s Stephen Amell, Game of Thrones‘ Emilia Clarke or Lena Headey… and the list goes on.

In fact, we crunched the numbers, and over the past five-and-a-half seasons, only 20-ish percent of SNL hosts have been “TV stars” (i.e. actors whose primary gig at the time was a TV series and only a TV series). And of that 20 percent, many of the TV stars’ hosting gigs coincided with the release of a major movie in which they starred. For example, while Chris Pratt’s Season 40 hosting stint occurred while he was still on Parks and Recreation, it was pegged to the release of Guardians of the Galaxy. Similarly, Girls‘ Adam Driver was promoting Star Wars: The Force Awakens. How I Met Your Mother‘s Jason Segel had The Muppets. Amy Schumer had Trainwreck. Seth MacFarlane had Ted. Martin Freeman had the third Hobbit film.

Aside from starring in a buzzy film, two other criteria give TV stars the occasional leg up: being an SNL alum (see: Fred Armisen, Andy Samberg, Jimmy Fallon, Maya Rudolph), or a singer with a huge following (The Voice‘s Blake Shelton and Adam Levine).

All told, since the 2011-12 season — out of more than 100 hosts — you can count on three hands the number of non-SNL alum TV stars who went “Live, from New York!” Here’s the list: Game of Thrones‘ Peter Dinklage, Louie‘s Louis C.K., Empire‘s Taraji P. Henson, Girls‘ Lena Dunham, The Big Bang Theory‘s Jim Parsons, Scandal‘s Kerry Washington, 30 Rock‘s Alec Baldwin, New Girl‘s Zooey Deschanel, Boardwalk Empire‘s Steve Buscemi, Up All Night‘s Christina Applegate and the aforementioned Vergara. And sources close to two of the above A-listers (who requested anonymity) tell me that they had to work fairly hard to sell the SNL brass on said actor/actress before a commitment was made.

“It’s perplexing for sure,” noted one of the frustrated publicists. “It’s at the point where we don’t even bother pitching them a TV client because we know it’ll be met with silence. Or they’ll say, ‘Yes, we’re tracking them,’ and that’s the last we’ll hear. It’s frustrating.”

Lest you postulate NBC is loath to draw attention to a competing show, it would seem that even being on a Peacock series doesn’t give you an advantage. If it did, The Good Place star Bell would’ve hosted the season opener, and any cast member of NBC’s breakout hit This Is Us would be fronting this weekend’s show. After all, as one insider points out, “Lorne Michaels is not beholden to NBC when it comes to booking guest hosts. He has, for the most part, complete autonomy.” (Michaels declined TVLine’s request for comment.)

One could argue that production schedules are a unique obstacle to TV talent participation. It’s tough for an actor shooting 14-hour days to find the time to go to the grocery store, let alone spend a week in New York in the middle of the TV season. But after talking to nearly a half-dozen studio and network executives, we were hard-pressed to find one example of a guest-hosting overture that fell through due to scheduling conflicts. As one exec insists, “We never had an offer we could not accommodate.” Networks and studios view overhauling a production schedule as a small price to pay for the kind of exposure an SNL gig can bring (hence ABC’s willingness to let Washington — who is pretty much in every scene of Scandal — take a week off; ditto Empire‘s Henson).

Another exec at a major TV studio said they would move “heaven and earth” to ensure the star of one of their shows could host SNL. “Unfortunately,” that insider sighs, “we’ve rarely had that problem.” TV's Best, Worst and Most of 2016 (Part 1)

So what’s behind the double standard? The entertainment business as a whole has long since gotten past TV’s “second-class” status, so why not SNL? Everyone we spoke to was hard-pressed to explain the ongoing slights, with one exec reasoning that perhaps Michaels “feels that TV stars are too accessible and not as ‘mysterious’ as a movie star who only becomes available once a year, when they have a movie to promote.”

Another longtime publicist puts it more bluntly, sniffing, “It’s snobbery, plain and simple.”