CBS had the hots for Lizzy Caplan, but the “Party Down” star didn’t want to commit to “Mad Love,” the network’s new romantic sitcom. Fox was dying for David Cross, but an erupting volcano prevented the comedic actor from showing up on the pilot of “Running Wilde.” In Detroit, art imitated life too closely when camera crews were banned from riding with the city’s cops, undercutting the premise of ABC’s “Detroit 1-8-7.”

Beginning this week, the nation’s television critics are gathering in Beverly Hills for the TV industry’s semiannual rite of hyping shows for the new season. Behind the scenes, another annual ritual is unfolding as network executives and producers frenetically labor to perfect their programs. In some cases, that means just a few tweaks in the editing room. In others, it means a major series overhaul with new actors and new scenes. Although difficult to gauge precisely, the level of rejiggering seems notable this season -- of the 37 new scripted shows, more than 20 have had changes and at least 17 actors were replaced.

Among the actors who went from pilots to unemployment: Ryan Devlin was replaced by Jonathan Sadowski as the son of William Shatner’s character on CBS’s comedy "$#*! My Dad Says.” Maura Tierney (“ER”) took over for Joely Richardson (“Nip/Tuck”) in ABC’s “The Whole Truth.” NBC changed two actors on “Friends With Benefits.” Zach Cregger took over Fran Kranz’s role and Andre Holland replaced Ian Reed Kesler.

Networks and producers often cite “creative reasons” for dropping an actor. But that can mean almost anything. Sometimes a show changes direction, and at other times focus groups can decide an actor’s fate. And then, of course, sometimes an actor doesn’t work and play well with others.

In the case of Fox’s “Running Wilde,” the changes were the result of both a creative shift and Mother Nature. Fox and executive producer Mitch Hurwitz wanted David Cross -- who had worked with Hurwitz and the show’s star, Will Arnett, on Fox’s “Arrested Development” -- to play the fiance of Keri Russell’s character. But forces beyond Hollywood intervened and trapped Cross overseas after air travel was shut down due to an active Icelandic volcano. The network temporarily replaced the comedic actor with Andrew Daly.


But Cross won’t be the only new face on the show. Fox is looking for a new actor to play Migo, a caretaker to Arnett’s character, originally played by newcomer Joe Nunez.

“It’s not fun at all to have those kinds of conversations with an actor, especially with someone new like Joe,” said Bob Huber, Fox’s executive vice president of casting.

In a few cases, it wasn’t that the network cast the wrong actor. It was that they couldn’t land the right one. That’s what happened with CBS and Caplan on “Mad Love.” Best known for her stint on the now-canceled Starz comedy “Party Down,” Caplan was the favorite for the role of Connie, a sarcastic and jaded sidekick to the lead character, Kate, played by Minka Kelly of “Friday Night Lights.”

But Caplan, who wanted to keep her options open for movie roles, agreed to appear in the pilot only as a favor and warned network executives upfront that she would not accept the role even if the series were picked up. When CBS ordered the series, the actress -- as promised -- turned down the part, a move that led to not only the hiring of Judy Greer (“Arrested Development”) for Caplan’s part, but the replacing of Kelly with Sarah Chalke (“Scrubs”).

“This was a very particular circumstance.... We hoped she would become available,” said Wendi Trilling, CBS’ executive vice president of comedy development.

NBC made bad bets hiring actors Jordana Spiro and Kyle Howard for its midseason comedies “Love Bites” and “Perfect Couples,” respectively. The actors, who already had jobs working on the TBS sitcom “My Boys,” only would have been free if that series had been canceled -- but it wasn’t. Now, Kyle Bornheimer is set to star in “Perfect Couples” and Spiro’s role on “Love Bites” might be eliminated, according to network sources.

Replacing an actor on its own is not a huge blow to the bottom line. A typical comedy pilot can cost as much as $3 million and dramas can easily top more than $5 million. Actor salaries in a new series can range from $15,000 to $125,000 per episode. Each time an actor is swapped, it means scenes have to be reshot. Executives think that’s better than the alternative.

“We are not going to keep a cast member who is not working because it would be a little more expensive to make the change,” said Trilling. “If we did, we might have a dead series, which would be much more expensive.”

Hiring actors who are already committed elsewhere is not so odd as it may first appear. During pilot season, there are often a number of roles that need to be filled simultaneously across the networks and the hope is that desirable actors will become free as series get canceled and other pilots die. Known as “second position” casting, some executives don’t think the risks of the practice are worthwhile.

Of course, it’s not always about actors. In the case of “Detroit 1-8-7,” four days of reshoots in the Motor City were recently completed to remove the documentary-style storytelling device used in the pilot. The ABC drama, created by Jason Richman, will still follow a group of Detroit homicide detectives but they will no longer be trailed by a documentary crew and characters won’t speak directly into the camera.

The change was one ABC executives had wanted all along, according to network sources. Then, in late May, after ABC ordered the show, the Detroit mayor banned camera crews from riding along with the city’s cops, after a 7-year-old died during a raid being filmed by A&E;'s “The First 48.”

“It was literally the one city where you were threatening credibility by saying that’s what the show was,” executive producer David Zabel said. “But it’s not an objective show. It’s told from the point of view of the detectives and hopefully by taking away the cameras, we’re freeing up our characters to be themselves.”

Given the development process, it’s unlikely the maddening reworking of programs will disappear. Every spring, hundreds of scripts are ordered and scores of pilots are shot concurrently, which means intense competition for actors, crews and directors.

“It’s about evolving the thing,” said Matt Cherniss, Fox’s executive vice president of program development, “and when it comes together, it’s a unique experience that I’m not sure you get in another creative business.”