In the years I’ve been covering broadcast development, I have rarely seen so many recastings before pilots were filmed. There always have been some tweaks between the table-reads and the shoots (and even more after the upfronts on the pilots picked up to series) but nothing on the scale of what we’ve witnessed this season. The first major recasting actually came very early on when Ryan Phillippe exited the CBS drama pilot Golden Boy shortly after signing on for the role. He was eventually replaced with British actor Theo James. The CBS drama was one of a whopping three pilots to recast their leads this year. The other two, Fox’s comedy Ned Fox Is My Manny and CBS’ Greg Malins/Greg Berlanti comedy, did it after the table reads. Dakota Johnson was brought in on Ned Fox to replace originally cast Abby Elliott, and David Walton succeeded Bryan Greenberg on the Malins/Berlanti project.

There were also a slew of co-starring role changes after table-reads and run-throughs this season. Zachary Gordon replaced Aidan Potter as Mary McCormack’s son in Kari Lizer’s ABC comedy pilot when the boy was made older. Tricia O’Kelley took over from Salli Richardson in NBC’s comedy pilot Downwardly Mobile. Martha MacIsaac replaced Brittany Snow as the First Daughter on the NBC comedy pilot 1600 Penn. Amanda Walsh replaced Aly Michalka in the Fox comedy pilot Rebounding when the character was reconceived, Sara Rue replaced Courtney Henggeler in NBC’s Jimmy Fallon comedy pilot (in second position to ABC’s Malibu Country), and Mike Castle succeeded James Pumphrey in the ABC Mandy Moore comedy pilot. On the CBS comedy pilot Partners, Elizabeth Regen was replaced with Tracy Vilar after the table read, while another role played by Lucy Davis was written out, with a new character, played by Molly Shannon, introduced.

What is behind the large number of pre-shoot pilot recasts this season? Some industry insiders point to the dramatic evolution in the way pilot casting decisions are made. In the past, the finalists for each role would go to the network for a test in front of network and studio executives, sometimes alongside actors already cast in other roles in the pilot. The executives would then convene after the auditions to discuss the candidates and pick the one they felt the strongest about for the role. Fox was the first network to switch to testing actors on tape several years back. This year, an estimated two-thirds of the pilot auditions were taped at the studios and emailed to the networks, with CBS the only net that offered the choice for in-person tests on all its pilots. “The technology got up to a point where the studios are able to put an actor on tape, email the audition to the network and get an OK in half an hour,” one insider said, adding that the speed and lack of communication “has led to some of these mistakes.” In most cases, executives see a pilot’s cast members together for the first time at the table-read. That’s when some mis-castings become clear, like Josh Gad and Brittany Snow playing brother and sister. Adding to the pressure is the fact that, with so many pilots produced at the same time, competition for sought-after talent is often fierce, forcing casting executives to make a decision fast or risk losing a hot actor to another pilot.

Which brings us to the heart of the problem — the broadcast pilot season model. After taking up to nine months to develop their pilot scripts, the networks rush to make as many as 90 pilots in three months, all at the same time. The window for casting those pilots has shrunk significantly over the years — from 10 weeks, which had been the standard for decades, to roughly 4-to-5 weeks now. “The process is so flawed,” one insider said, “it’s actually surprising that so few mistakes are made.”