In a sketch last week during his second hosting gig on “Saturday Night Live,” Louis C.K. had a rough time. Many of his remarks in “Black Jeopardy” as the character Mark were not only offbeat, but also awkwardly racist.

Watching celebrities behave uncharacteristically has always been one of the main draws for audiences of “SNL,” now in its 39th season on NBC. But the attraction of “SNL” — one of the most discussed and longest-running shows on television — should not be scenes that put famous people in uncomfortable situations.

Even during “Black Jeopardy,” one of the most shared videos from last week’s episode, the laughs come from the writing. Theoretically, any white male — whether celebrity host or cast member — could have played C.K.’s role and it would have been just as funny.

The “SNL” audience seemingly consists of two groups. There are diehard sketch-comedy fans who are lifelong watchers and truly care about the show. On the other hand, there are those watching solely for the celebrity guests.

The first group will argue that sketch writing is a labor-intensive process and that when it works, which it often does on this show, the result is hilarious and seems effortlessly funny. The other group will argue that, for the most part, “SNL” is not all that great, but it is enjoyable when stars act silly.

But what this second group does not realize is that a sketch with stars acting silly is not inherently funny. Even if Matt Damon puts on a dress and hits on Kenan Thompson, his dialogue is what makes even the haters laugh — the dress and the man are just there to fulfill the writer’s vision.

For this reason, the seasons’ best episodes are those hosted by former cast members or by celebrities who have hosted multiple times. Stars like Jimmy Fallon, Steve Martin and Justin Timberlake are either writers themselves or are familiar enough with “SNL” that they end up serving the show, rather than the other way around.

Where the host really comes in, as with the rest of the cast, is the delivery. Comedic timing cannot be taught, especially in a single week. For the writing to make sense, the host must be a good actor, even when the lines continue to change until the last second and there is little time for memorization or rehearsal.

While “SNL” hosts deserve a share of credit for the success of their episodes, there is a reason why almost every host has come away astonished at the talent and determination of the writing staff. While people may watch for the celebrity host, they will laugh mostly for the writers, whether they know it or not.

A version of this article appeared in the Thursday, April 10 print edition. Sean Hickey is a staff writer. Email him at [email protected].