Word had it that by the time Warren Leight took over as "Law & Order: SVU" showrunner in the series' 13th season that the job would be a temporary assignment. "There was a sense that it would be 13 and out. Welcome to the Titanic." he said. "It needed to be shaken up."
Shaking up any show, much less the longest-running live-action scripted series on TV right now, is tricky. A show in double-digit years is its own brand, with a cadre of loyal fans who may resist change. But a show that can't evolve is dead in the water.
"What's hard is you're going up against all of the episodes that have ever aired, all the precious moments people felt from 'The Simpsons' in their lives," says executive producer Al Jean about his series, now in its 25th season. "We don't treat it as sacred and unchangeable; we try to be fresh."
Jean and company are lucky in that they never have to worry about actors aging out of roles; Yeardley Smith can go on being a young Lisa Simpson ad infinitum. In fact, "The Simpsons" has changed remarkably little since its debut in 1990: There are no more rotary phones on the show; TV sets are generally flat screens. Jean said the pace of the show picked up around its fourth season, but added, "We're still trying to do the same kind of show we did at the beginning."
Not all shows have it so easy; cast changes tend to be the wellspring from which show shifts take place. "CSI" (now in Season 14) cycled through lead investigators played by William Petersen and Laurence Fishburne before arriving at Ted Danson, and by then, said executive producer Don McGill, they wanted a "fresh take on a classic cop" -- a character whose job didn't destroy his life and who could keep it separate from his home life. So D.B. Russell (Danson) was created.
But on long-running shows, creating change is a tightrope, McGill said. "There is a pressure on forensic procedurals all over TV now not just to differentiate yourself from other shows, but from seasons past. Audiences want to tune in to see classic 'CSI,' but they also want something fresh and original."
The departure of "SVU" original cast member Chris Meloni was a signal for Leight to reinvent more than just characters; he made sure more personal stories were being told and that scripts stopped being written "for the twist, and the twist in the twist." And victims of crime survive; there are fewer corpses. "It was a reinvigoration through Chris' departure," Leight said.
In the case of "Bones" (now in Season 10), the union of Booth and Brennan was inevitable almost from Episode 1, but showrunners Hart Hanson and Stephen Nathan fought making it happen too early. "Around 2009 or 2010, we got a ton of pressure from everybody to put them together," Hanson said. "We looked at each other and said, 'It's not time yet.' Fans don't know that it's the frustration [in the characters' relationship] that keeps them watching."
Nathan insisted that it's about looking for the "natural evolution" of the show: "If you follow the characters, rather than impose what you want the characters to do, they lead you in different directions."
"That's a terrible answer," Hanson shot back, quipping: "We're geniuses who have balanced a delicate crystalline structure over nine seasons, with constant debate."
Reality shows may not have to face the kind of casting changes scripted series do, but that doesn't mean they're without issues over the long term. "Reality shows are more nimble than scripted ones, but they're less predictable," said "Hell's Kitchen" executive producer Arthur Smith (the show is in its 12th season). Over the years the show has become more documentary-like, thanks to 82 cameras positioned around the kitchen and restaurant facility. "We don't have to create drama," he said. "It's all there."
"American Idol," now in Season 13, suffered a serious wound when judge Simon Cowell left in 2010, but has bounced back to some degree with a rotating series of celebrity faces and gentle recalibrations of the format. Gone are the so-bad-they're-funny singers, and the parade of sob stories is shorter. "We listen to the viewers, and they tell us," said executive producer and president of programming for Fremantle Entertainment Trish Kinane. "It's a million small things that refresh the show without compromising the core format."
And, of course, reality shows will never have to worry about casting fodder; as Kinane noted, "Kids turn 16 every day -- there's a whole new group of contestants every day for 'Idol.' We had people this year who had auditioned in the past, whose kids were now auditioning."
Long-lived shows may be fading into the past, subsumed by 13-episode (or fewer) series with shorter runs. But there is something secure and old-fashioned about a series that lasts the decades, providing comfort food and a jolt to the system all at once.