Spinoffs have long been a staple of the broadcast network landscape, but precious few have successfully captured an audience to such a degree that they lasted as long as the series that spawned them in the first place. “Frasier,” however, managed to defy the odds: it made its debut on NBC 25 years ago and ran for 11 seasons, which is the same length of time that its predecessor “Cheers” maintained its slot on the prime-time schedule.

“A lot of times shows really evolve a lot over the course of the first season, when you kind of discover what you have, but ‘Frasier’ was pretty solid going in,” Ken Levine tells Variety.

Levine wrote, directed and served as a creative consultant on the series at various points during its run. Some things, he admits, were discovered along the way, but he says there was never the need for “a real sea change.”

“It’s not like ‘Happy Days,’ where they discovered, ‘Oh, my gosh, the money is The Fonz,’ or ‘Family Ties,’ which was supposed to be about the parents until they realized that Michael J Fox was the money. ‘Frasier,’ I think, pretty much stayed the course throughout,” he says.

The reason for this, Levine credits, was the character of Frasier Crane himself.

“A lot of times the problems with spinoffs are that the supporting characters are elevated, and they’re better served as supporting characters, because they can’t really carry a show on their own. In this case, Kelsey Grammer as Frasier was the one character who clearly was fleshed out enough and had the presence and had the star quality that you figured he could indeed pull it off,” he says.

The “Frasier” story actually began in 1990, three years before the end of “Cheers,” when Kelsey Grammer — reasonably presuming that his current gig was destined to wrap up within a season or two — first began formulating a plan of action for a series of his own. At the suggestion of Dan Fauci, a vice-president of development for television at Paramount, Grammer sat down with the writing/producing team of David Angell, Peter Casey and David Lee, who’d spent time working on “Cheers” and then went on to create “Wings,” and invited the trio to work with him on his next series.

The initial idea was to allow the Frasier Crane character to “retire” alongside “Cheers,” recalled Grammer in his 1995 memoir, “So Far…” Instead, he would play a bedridden mogul, “a man so driven and wealthy that being in bed didn’t stop him from virtually running the country as he’d done before.”

However, John Pike, the then-president of Paramount TV, didn’t think it was a funny concept, and “that pretty much said it all,” Grammer wrote. But fortunately, Pike had an alternate suggestion: continuing the adventures of Frasier. Grammer ended up agreeing, if his story could start fresh. This meant not only leaving Boston but also his wife, Lilith, played by Bebe Neuwirth. Since a storyline in the final season of “Cheers” involved Lilith having an affair, it wasn’t difficult to allow the character this transition.

As history reveals, “Frasier” took the often-loquacious Dr. Crane and utilized both his skill as a psychiatrist and his gift for gab by transforming him into a radio show host in Seattle, Wash., but Angell, Casey, and Lee conceived of an additional reason for Frasier’s relocation: he had family there.

At first, the idea was for Frasier to join his father Martin (played by John Mahoney) in the Northwest, as in “Cheers,” the character once said he was an only child. Bringing in a brother, Niles (played by David Hyde Pierce), was a later-in-development revelation.

“One of the casting directors for the show, Sheila Guthrie, saw David Hyde Pierce in a play and remembered having seen him in a short-lived Norman Lear series and thought, ‘Boy, he’d be a great brother if they ever wanted to add one!'” Levine says. “So she came to Casey, Lee and Angell with a tape and said, ‘Would you guys look at this for five minutes? This might be something interesting.'”

Levine says they “immediately recognized the potential” of adding another family member to the dynamics. Similarly, the inclusion of a home care worker for Martin, Daphne Moon (Jane Leeves), as well as Frasier’s acerbic radio producer Roz Doyle (Peri Gilpin), lead to further conflict and comedy.

“I don’t remember why, but I know Kelsey had a certain reluctance about the character being British,” says Levine. “But then he met Jane, and after sitting with her for five or ten minutes or whatever it was, he was completely on board and said, ‘Absolutely! Let’s hire her!'”

Roz was originally set to be played by future “Friends” star Lisa Kudrow, but during the week of pilot production, the decision was made to replace her.

“Lisa was fabulous, and things sure worked out well for her,” says Levine. “It was only because she just wasn’t that character. There was an edge that the character of Roz required that Lisa just organically didn’t have.”

Enter Gilpin, who remembers the role coming down to Kudrow and herself, even after “they read many, many, many people for it,” she says. “I had done two series with Jimmy Burrows, the Charles brothers, and Fran McConnell at Paramount for Jeff Greenberg, so I had been on the lot for a long time, and I had just done the fourth-to-last episode of ‘Cheers,’ so I was sort of around that area.'”

With its core cast in place, “Frasier” was off and running, and during the course of its 11 seasons, kept the same cast intact. Over the years, the sitcom broke the record for the most Emmy Awards for a series, earning 37 total (It held the record until 2016 when “Game of Thrones” earned its 38th trophy). It is still tied (with “Modern Family”) for series with the most consecutive comedy series wins, though, with five from 1994-98.

Given how prevalent series revivals have become in recent years, it’s none too surprising that conversations have already begun about bringing Frasier Crane and company back to the airwaves.

“I wouldn’t want to harm the legacy of something that was so well done by so many people, some of whom aren’t here anymore to weigh in,” Gilpin says. Angell, for example, passed away in the Sept. 11 2001 terror attacks and Mahoney died from health complications earlier this year.

But, Gilpin continues, “if there was a way that everyone agreed on — not me, but David Lee and Peter Casey and Kelsey and Jimmy Burrows and all of those guys — and everybody thought it was a good idea, then yeah. Hell, yeah!”