The Emmys’ guest actor and actress category names may have evolved over the years, but ever since the Academy first honored seasoned actor and director Patrick McGoohan for a stint on NBC’s “Columbo” they have had a reputation for celebrating well-known talent.

Some of this is also due to repetition. NBC’s “Saturday Night Live” has been a mainstay in the guest acting comedy categories the past decade. Since 2009, the late-night sketch show has won half the trophies awarded in those categories — nine of 18 — with victors ranging from Justin Timberlake and Jimmy Fallon to Tina Fey and Betty White. Last year, hosts Dave Chappelle and Melissa McCarthy won their respective categories, and a total of five of the 12 nominees were from the show.

Since “SNL” guest hosts use the show’s platform to promote their own work, it’s inevitable that they might also be eligible for other Emmy categories. This year’s potential crossover nominees include Tiffany Haddish, who stars with Tracy Morgan in TBS’ “The Last O.G.,” and “SNL” alum Bill Hader, who co-created and stars in the HBO dark comedy, “Barry” (Hader was also nominated in the comedy guest actor category in 2015 for hosting “SNL”). But this year’s “SNL” hosts also include Sterling K. Brown, who is effectively competing against himself in the guest actor in a comedy race because he also did guest stints this season on Fox’s “Brooklyn Nine-Nine” and HBO’s “Insecure.”

Comedies give actors a chance to drop in and steal scenes. During the original run of “Will & Grace,” many guest actors earned nominations. Since the show’s reboot this season, actors including Molly Shannon, Blythe Danner, Nick Offerman and Bobby Cannavale are just a few eligible for noms this year. Other comedies that could dominate include “Curb Your Enthusiasm,” “Modern Family” and “The Big Bang Theory,” which saw plenty of funny star turns. On the drama side, such shows as “The Handmaid’s Tale,” “The Good Fight” and “Scandal” have many great guest opportunities.

Brown is also, of course, again eligible for lead actor in a drama for his day job on NBC’s “This Is Us,” a show that itself fielded three guest actor in a drama nominees last year and could dominate the drama side this year. Actresses who guested on the hit show include Kate Burton, Pam Grier, Elizabeth Perkins and Lena Waithe. On the actor side, there’s last year’s supporting nominee Ron Cephas Jones and reigning winner Gerald McRaney, who pops in sporadically to play the wise and fatherly Nathan “Dr. K” Katowski. McRaney took a break from filming USA’s “Shooter” — in a role that would make Dr. K’s fans cry in a different way — to say that television creators and casts have no one to blame but themselves for this proliferation.

“Because of the advent of cable and streaming and just all manner of different formats to deliver product to an audience, the competition has generally gotten higher, and the quality of all the programming has gotten higher,” McRaney says. “I think the networks have figured out that the audience out there in Peoria isn’t quite as stupid as they originally had thought they were. So they started to do better and better programming. So, naturally, all of the acting categories get to be more competitive, including the guest category.”

Brooke Shields may see things similarly. Although the “Suddenly Susan” and “Lipstick Jungle” alum says she’d “probably love nothing more in my life than having a set that’s mine to go to” full time again, she has kept herself quite busy with guest starring roles. Like Brown, she’s also eligible for three guest acting roles this season.

One is for an arc on “Law & Order: Special Victims Unit” that allowed her to show a much more wicked side as the meddling Sheila Porter. The others are for the comedies “The Middle” on ABC and “Jane the Virgin” on the CW — the former involving a mullet and a good deal of swagger for her last bout as troublesome neighbor Rita Glosser, and the latter as a well-coiffed celebrity named (ahem) River Fields.

“It’s important to me, vocally even, to make my ranges as wide as possible,” Shields says. “Guest starring in other peoples’ shows enabled me to have that diversity within roles and versatility within characters. For this season, those roles started bouncing back and forth. It’s what excites me — learning and growing.”

As to playing a parody of herself on “Jane” -— especially one that makes her address old issues like her public feud with Tom Cruise about post-partum depression and her use of antidepressants — Shields says she’d only agree to do the role if it was a character. She says it’s much more fun that way because “playing a character of what the people think this person is; there’s no accountability,” and “you can have all this freedom to how you switch her because nobody’s attached to her yet.”

None of this is to say that talent with established household names should be the only ones used for guest acting roles — or that they’re the only ones put in the work. Jodi Balfour spent six weeks in London for her performance as Jackie Kennedy for one episode of “The Crown.” The Netflix show is another that could dominate the drama guest category, thanks to turns by actors including Matthew Goode and Michael C. Hall.

In addition to fittings, research and filming, she also spent time with legendary voice coach William Conacher to perfect the former First Lady’s notoriously breathy speaking pattern. She also talked with lead Claire Foy, who plays Queen Elizabeth II, about the similarities the women share.

“I was actually blown away by how little there was on [Jackie] online or in books or in documentaries that was about her truly behind closed doors,” says Balfour, who also stars in Cinemax’s “Rellik.” “I think the queen is just as much as a fortress. … What I saw as the struggle and the tension throughout is, in another circumstance and another world, these two women would have been best friends. But in the constraints of their lives, they have these facades to keep up.”

With guest acting, there can also be the fear of typecasting. Kristin Chenoweth says she was asked to appear as a flowy earth goddess with an odd notion of energy healing for one episode of CBS’ “Mom” because she’s a long-time friend of co-exec producer Marco Pennette, who co-wrote the episode.

“I feel that I’m getting roles that — and I don’t mean to sound arrogant — not a lot of people could play because they’re that unique, and they’re also sort of writing for me,” says Chenoweth, who also plays an alleged murderer in the second rendition of NBC’s quirky crime anthology, “Trial & Error,” which premieres this summer. “When you get those parts as an actor, you take them because they don’t come along every day,”

What she does say, however, is that actors shouldn’t go into a guest acting role just to secure the “E” in their EGOT showcase.

“What about having a part that’s remembered?” Chenoweth says. “I just want to do great work, and have my friends go, ‘that was good.’”

That methodology seems to be working for her. Chenoweth already has an Emmy. She won it in 2009 in the supporting actress field for the ABC comedy “Pushing Daisies.”