NEW YORK — Kenan Thompson is a sketch-comedy savant.

He’s seen how the tiniest diversion — uttering an errant word, glancing in the wrong direction, taking a half-second too long to rip off tearaway clothes — can create a disruption.

“He’s a master in that studio,” says “Saturday Night Live” executive producer Lorne Michaels. “He knows the best way to do just about everything.”

That includes realizing how distracting it would be for the audience to know there’s a performer with a broken arm. So when the SNL star got into a bike accident on his way to work four years ago, his first thought was: “ ‘Oh my God, I have to go to the hospital, but I don’t want it to be a story.’ ”

“The writers, they work so hard, they spend all night, and then the only thing people would be mentioning would be like, ‘Did you see Kenan’s broken arm?’ That’s whack,” Thompson says. “You never know how long they’ve been incubating an idea that they got on the show that week.”

He went to an urgent care clinic, slept sitting up and, before Wednesday’s table read — during which performers run through roughly 40 sketches — Thompson called three places to find a doctor who could cast his arm discreetly and quickly.

Three days later, SNL was hosted by Donald Trump, probably the biggest distraction in the universe. But Thompson took no chances in creating a minor one, even for a moment. He strategically propped his clothed, fractured arm on his waist, delivered his lines and no one noticed.

“Even just the smallest distraction throws off the potential of the experience of the joke,” Thompson says. “You kind of don’t have permission to not be perfect.”

Thompson, 41, is hyper-aware of camera positions, timing and the ripple effect his actions have on people just trying to do their jobs. That serious professionalism, multiple colleagues say, is the other side to what television audiences see at home — the breeziness of a natural performer who can summon humor anywhere. It’s a talent that puts him everywhere: as the straight man, as the bad guy, as the steady anchor in an iffy sketch centered on a rookie player. But his presence is like oxygen, not the sun. His power is essential, yet invisible; stimulating, not scorching.

“I would point to Kenan Thompson as the performer that I would watch and hope to attain that kind of confidence and ease and fun when he was performing,” says SNL alum Bill Hader, who struggled with severe nervousness during his time on the show. “He was like the safety net.”

Thompson, who will start his 17th season on the series in late September, occupies a rarefied place in popular culture. He’s the longest-tenured cast member on a famously challenging show to endure, where comedy icons are molded and tend to leave. And although he has several other projects in the works, including a new NBC comedy due in 2020, he has no desire to walk away from SNL.

“That’s the forever plan,” Thompson says. “To never have to leave that show.”

Kenan Thompson, 41, will start his 17th season on "Saturday Night Live" in late September. (Celeste Sloman for The Washington Post)

Thompson had broken an arm before. In second grade, he flipped off a swing but “never cried,” recalls his mother, Ann Thompson. “Very, very stoic.”

He was that kind of kid: self-contained, fearless and with a big imagination. He grew up in College Park, Ga., the son of a nurse and a mechanic, following his older brother, Kerwin, around, riding bikes and memorizing the lines to ’80s movies. While Kerwin sang at choir rehearsal, 4-year-old Kenan would sit on the ground and play with toy cars, dreaming up people and scenarios.

“He didn’t need constant attention where I had to hold him or reassure him all the time,” Ann Thompson says. “He just, he had his instructions, he would follow them and do his thing.”

When Thompson was 5, she enrolled him in acting classes at the urging of her friend, who saw talent in his childish play. His first role — Toto in a church production of “The Wiz” — had no lines, but “he absolutely stole the show,” his mother says.

He’d eventually go on to audition for 100 roles before ever booking a commercial gig.

“It’s really a challenge to console a child who didn’t get the part, but he wasn’t whining about it,” Ann Thompson says. “He always knew.”

Thompson eventually was hired to review movies on a kids’ news show, which led to his role in “D2: The Mighty Ducks ” and then Nickelodeon’s “All That.”

Thompson as Pierre Escargot, a recurring character on "All That." (Nickelodeon) Kel Mitchell and Kenan Thompson star in "Good Burger" in 1997. (TCD/Prod.DB/Alamy Stock Photo)

LEFT: Thompson as Pierre Escargot, a recurring character on "All That." (Nickelodeon) RIGHT: Kel Mitchell and Kenan Thompson star in "Good Burger" in 1997. (TCD/Prod.DB/Alamy Stock Photo)

“All That” executive producer Brian Robbins, now president of Nickelodeon, remembers a 15-year-old Thompson walking into the audition and effortlessly performing a “crazy spot-on” Bill Cosby impression.

“Everything was easy for him comedically,” Robbins says. “I had never met someone that young so gifted and smooth comedically.”

The show, conceived as an SNL for children, debuted in 1994 and would endure as a cultural touchstone for ’80s and ’90s babies.

“It’s not water-cooler talk, because we weren’t in any offices, but it definitely was juice-pouch talk,” says comedian Ron Funches, who grew up watching “All That.” “You know, just sitting around at lunch, eating our snack packs, drinking our Capri Suns and talking about how funny Kenan is.”

For the next six years, Thompson juggled several jobs, including “All That” and, along with castmate Kel Mitchell, the spinoff series “Kenan & Kel” and the “Good Burger” movie. During that time, Thompson honed the techniques and skills needed for being funny on camera, but he also exhibited the same spirit and work ethic he’s known for today, Robbins says.

“There was a moment there where he was one of the biggest kid stars on the planet, but he was always the same kid,” Robbins says. “He has not changed, and I believe that’s part of why he has sustained for so long.”

From left, Bill Hader, Carrie Brownstein, Samuel L. Jackson, Thompson and Jason Sudeikis in an SNL “What Up With That?” sketch. (Dana Edelson/NBC) Thompson, Adam Sandler and Kate McKinnon during the "Last Call" sketch. (Will Heath/NBC) Pete Davidson, Kenan Thompson and Beck Bennett rehearse the "Duel" sketch for SNL. (Rosalind O'Connor/NBC)

TOP: From left, Bill Hader, Carrie Brownstein, Samuel L. Jackson, Thompson and Jason Sudeikis in an SNL “What Up With That?” sketch. (Dana Edelson/NBC) BOTTOM LEFT: Thompson, Adam Sandler and Kate McKinnon during the "Last Call" sketch. (Will Heath/NBC) BOTTOM RIGHT: Pete Davidson, Kenan Thompson and Beck Bennett rehearse the "Duel" sketch for SNL. (Rosalind O'Connor/NBC)

Thompson sits next to Jimmy Fallon, puts on goofy glasses and grabs a mug. They’re playing sportscasters, reciting lines generated by a game of Mad Libs they just played on “The Tonight Show.”

“All right, welcome back, baseball fans,” Thompson says with a whistly affect. “I’m Steve Butt.” The word “butt” comes out like a punch, drawing a laugh immediately.

Thompson has been coming up with voices and facial expressions for nearly three decades. “I could’ve done that in my sleep,” Thompson later says of the bit as he walks through Rockefeller Center. “I mean — prewritten, and we just have to read? Reading is fundamental, kids.”

He heads to Studio 8H, where SNL shoots and, standing among the auditorium seats, looks down at the spot on center stage where he auditioned 16 years earlier. If he didn’t get the job, Thompson thought at the time, “I’m going to be stuck in my childhood forever.”

Now the SNL veteran calls that spot home base. “It’s to the point where I’ve walked these halls and these stairs and all this in and out of the studio so many times, it’s like, where did I live before?” he says.

But his 16 years “mean nothing when it comes to performing a new sketch on Saturday,” he says. “We have to earn every single laugh the same raw way, with a setup and a punchline. It never changes.”

Off-camera, Thompson moves and talks with quiet ease, his words deliberate. When he needs to perform, he slips into a different frequency without notice, like a sleight-of-hand magic trick. At the table reads, “you see this dude rock 25 sketches, and you’re like, ‘Oh man, he constantly finds it,’ ” says fellow SNL cast member Chris Redd.

It took several years for Thompson, who arrived at SNL in 2003, to find his footing. Then fan-favorite sketches like “What Up With That?” allowed his comedic, singing and directing chops to take center stage. In the fake BET talk show, Thompson’s character playfully interrupts his famous guests with an increasingly elaborate theme song. “I had the best seat in the house,” says Hader, who played a silent Fleetwood Mac guitarist Lindsey Buckingham in the recurring sketch. “I would just sit and watch him sing and dance and be hilarious and switch it up.”

When Samuel L. Jackson cursed on live TV, Thompson immediately quipped: “Come on, now! That costs money.” Hader was astonished. “Wow! How fast he was when he came up with that,” he recalled. “When I think back, those are the memories that will hit first. I was only sitting there and watching Kenan.”

Thompson’s approach to sketch comedy, he says, is to be just as entertained by the jokes as the audience watching at home. “Part of that is me not wanting to feel like I’m at work every single time I’m performing, because that’ll stress you out,” he says. “And that panic can just take you out of a natural, good performance.”

That aura of joy allows senior writer Bryan Tucker to write roles for Thompson that could be caustic or controversial in another person’s hands. “Black Jeopardy” sketches traffic lightly in racial stereotypes, but Thompson makes them “fun and gregarious.” He can even make an imprisoned cannibal up for parole be likable. “He was just kind of adorable doing it, playing somebody who had eaten a bunch of people,” Tucker says.

Thompson, who came to SNL armed with a career’s worth of technical expertise, has since become a crucial element to the show and “the person I most rely on in the cast,” Michaels says. Like Dan Aykroyd and Phil Hartman before him, Michaels says Thompson doubles as a metronome, someone who adjusts the pace on the live show, speeding up or slowing down sketches as needed.

He’s also known for informally dispensing technical lessons, whether about camera blocking or the importance of sticking to cue cards. “So much of a funny sketch can be made or broken by the way it’s shot, or the production elements of it,” SNL cast member Aidy Bryant says via email. “Having Kenan in your sketch means you also have a producer, director and a writer.”

And while “he is quite glad to be the star,” Tucker says, “he’s also glad to play service, somebody who stands back and lets other people be funny. He also shows the cast how to make big things out of small parts.”

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Thompson finally received more formal recognition last year with two Emmy nominations and one win for “Come Back, Barack,” a ’90s R&B parody music video with Redd and Chance the Rapper. For the video’s rain sequence, Redd and Thompson had to stand in a torrent of water that, thanks to a technical glitch, was freezing cold. When the director asked for a third take, Redd says he wondered: Did they really need the scene? “I felt bad that I’m making this decorated sketch legend just be wet and cold.”

“You know what, man?” Thompson responded, according to Redd. “We’re already wet. Let’s do this.”

SNL is a high-stress environment where “you’re locked in a cage for nine months” and “all of you think you’re about to get fired,” Hader says.

“That place, it’s impossible not to close the door and bitch about people,” Hader says. “I never heard Kenan be like that. And if you did say it around Kenan, he’d be like, ‘Well, you know, they’ve got a tough job.’ ”

A lot of us can’t remember a time before Thompson was on our televisions. He was Pierre Escargot on “All That” before he was “Black Jeopardy” host Darnell Hayes; our comedic sensibilities matured alongside his comedic abilities.

While gray speckles in his beard betray his youthful countenance, Thompson’s face has largely remained the same. So when he takes a walk through Washington Square Park on a recent, cloudy 101-degree New York day, he naturally gets recognized by a spectrum of people, including a young mother who asks for a picture with her son.

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“Hey, little man, how old are you?” Thompson asks. “Two!” he proclaims, and Thompson picks up the smiling child. After the photo, the boy runs after the actor, grabs his hand and tries to join the walk. “I feel like kids can smell it on me now,” says Thompson, who has two young daughters with his wife, Christina Evangeline. As one of the few parents on SNL, he doesn’t spend much time outside work hanging out with fellow performers. “I’m always running home to my kids.”

Thompson cites his family as the reason he was able to live most of his life in the insane world of celebrity while not succumbing to its pitfalls.

“We’re all very humble and come from humble beginnings,” he says. “My generation of cousins, we’re all doing our thing now, but all of our parents struggled like for real, because they’re one generation removed from Jim Crow.”

Ann Thompson was a constant presence during his child acting days, working seven days straight and then spending the next seven with Thompson wherever he was filming. “You have to treat everyone with respect because you’re not a star all by yourself,” she says she’d tell him. You’re in the spotlight, but “there are a lot of people that are responsible for you being where you are.”

Thompson has found himself in the spotlight under more uncomfortable circumstances, too, like after a 2013 interview with TV Guide about the lack of black women in the SNL cast. He has said since that his quote — “they just never find ones that are ready” — was misconstrued as him saying there weren’t black women funny enough for the show.

“I would never in my life disrespect my culture like that, or my sisters,” he says now. “What I did want to do was better prepare people for that experience.” He remembered when he first joined SNL. “I had been in business for years at that point, and I still didn’t really know how to approach that place.”

Thompson, Dani Lockett as Emma and Dannah Lockett as Sophie in "The Kenan Show," an NBC single-camera comedy Thompson will executive produce and star in as a widowed father of two daughters. (Ron Batzdorff/NBC)

Following that controversy and a larger conversation about representation, SNL held special auditions and hired Sasheer Zamata and Leslie Jones, who has since become one of Thompson’s closest friends on the show. “If I have to be the villain for them to hire some women up here, I will be that,” Thompson says.

Representation is on Thompson’s mind as he approaches his future. He’s executive producing Nickelodeon’s “All That” reboot and is a producer and judge on NBC’s “Bring the Funny.”

He’s also pitching new projects, citing the dearth of black-owned production companies making comedies. “It’s almost like the SATs,” Thompson says of the limited opportunities for comedic actors of color such as himself. “Like I have to do great at a test that doesn’t really suit my upbringing and what I’m familiar with.”

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Meanwhile, he stands at another precipice in his acting career: Next summer he will shoot the NBC single-camera comedy “The Kenan Show,” which he will executive produce and star in as a widowed father of two daughters. The famously unflappable performer is nervous. “It’s all a reflection on me,” he says. “This will be me, and everything that people see me in, in that show, needs to be enjoyable.”

Two hours into his outdoor stroll, the sky finally breaks open. Rain floods the streets and, unfazed, Thompson casually walks to an awning for shelter.

But unlike the “Come Back, Barack” shoot, this cold water is a blessing, giving an outlet to the heat and pressure that had all day to accumulate.

It was only a matter of time, Thompson reasons. Just like his decades-long career, “if you build up that steam, it’s gotta have a release.”

Thompson says 16 years on SNL “mean nothing when it comes to performing a new sketch on Saturday.” “We have to earn every single laugh the same raw way, with a setup and a punchline," he says. "It never changes.” (Celeste Sloman for The Washington Post)

Story by Elahe Izadi. Portraits by Celeste Sloman, photo editing by Moira Haney. Video by Ashleigh Joplin. Design by Eddie Alvarez.