Scheduling history: Castle premiered in midseason 2009 in the Monday 10/9c timeslot, and it's aired all 81 episodes thus far in that hour.
See (who saw) how it all began: Castle opened up with 10.76 million viewers and a 3.0 adults 18-49 rating for its post-Dancing with the Stars premiere on March 9, 2009. That didn't appear all that promising because Dancing (22.83m, 6.1) had one of its biggest season premieres ever on that night. The show dropped just a tick (to 2.9) in week two, but for most of the rest of season one it settled in the low 2's. Considering it didn't actually have a DWTS lead-in for much of April, that was good enough for a renewal in what was an otherwise disastrous season for ABC's development.
The best of times: The peak episodes for Castle came at the beginning of the spring 2010 season of DWTS, when Castle had a two-parter guest starring Dana Delany (who would score her own ABC procedural Body of Proof the next season). The first episode on 3/22/10 was seen by 12.21 million viewers and posted a 3.3 demo rating, then the conclusion the next week hit series highs with 13.86 million and a 3.5. On the whole, the show has gradually gotten a bit stronger relative to DWTS each season, with the raw numbers growing a bit in both seasons two and three.
The worst of times: 70 of the 81 episodes of Castle have scored a 2.x in the demo. Only twice has the show dropped beneath the 2.0 threshold, and both of those were without its usual big DWTS or The Bachelor lead-ins (on 4/13/09 after Surviving Suburbia and on 12/6/10 after Skating with the Stars). Season four brought the worst numbers on the whole, largely a function of both DWTS seasons and The Bachelor all being down more than 20% year-to-year.
Then vs. now: One of my theories about network scheduling is that the best way to keep your timeslot is to be good but not great. Castle is as good an example of that as anything, yet another of those shows that seemingly everyone except for the network in charge wants to move from its timeslot. Instead, ABC will begin its fourth straight fall with Dancing with the Stars and Castle on Monday night. Though Castle has improved as a retainer of the Dancing with the Stars audience, its ratings are still to a large extent dictated by what happens with DWTS, and there's a lot of pressure on DWTS coming off of arguably its two weakest seasons yet. So while ABC clearly has no interest in voluntarily shaking up Monday, their hand may soon be forced if panic time sets in for DWTS.
Adults 18-49 info by season:
|Premiere||Average||Finale||P -> F|
For more on The War of 18-49, my look at the history of primetime TV's veteran shows, see the Index.