In the midst of an ambitious plan to reinvent the way the broadcast networks operate, FOX entertainment chief Kevin Reilly ran into a very traditional problem: not enough hits. So the man who wanted to cancel pilot season and seasonal scheduling has instead resigned from the network, effective immediately.

“21st Century Fox is a great company that has provided me with choice seats at the head table of pop culture over two very rewarding stints both at FBC and FX," Reilly said in a statement, "and I am grateful to have benefited from the leadership of Peter Rice, Chase Carey and Rupert Murdoch,” said Reilly. “Peter and I have been discussing this transition for a while, and now with a robust new slate of programming for next season and strength in the FBC ranks, it felt like the timing was as right as it could be. I couldn't be more thankful to my team – a group of creative, tireless and fun people whose fellowship I will miss.”

No replacement has been named yet; for the moment, Reilly's pre-existing team will report to Rice (who briefly ran the network himself before being moved further up the News Corp ladder).

Reilly is a smart man who's been in at the ground floor of a lot of major television breakthroughs. He was a development executive who worked on both "ER" and "The Sopranos" at an early stage, was helping to run FX when "The Shield" launched, was president of NBC when "The Office," "Friday Night Lights" and "30 Rock" were greenlit, and has been in his current post at FOX since 2007, where he took advantage of the "American Idol" cushion to experiment with shows like "Glee" and earlier this year at the Television Critics Association winter press tour delivered a monologue about his desire to kill the obsolete idea of producing all your pilots in a short window in late winter and early spring. (At the end of a letter he sent to FOX employees explaining his decision to resign, Reilly added, "P.S. – Don't go back to pilot season!")

But with "Idol" proving increasingly mortal this year, with one-time hits like "Glee," "New Girl" and "The Following" all shedding viewers, and with only three of this season's new shows returning for next year ("Sleepy Hollow," "Brooklyn Nine-Nine" and "Masterchef Junior"), Reilly's position was becoming less tenable.

As he acknowledged the ratings struggles of those and other shows, Reilly also said he had approval from on-high in News Corp to abandon pilot season, do more year-round scheduling, etc., and that everyone at the company understand this would be a process that would take years to fully implement. The subtext seemed to be that Reilly would be around to oversee that process, even if the network was struggling in the present-tense ratings. Instead, he's gone, and we'll see if whoever his successor is will have the authority and/or the desire to stick with those initiatives.