When fans say a TV series has jumped the shark, do the masses really notice? We did some research on Battlestar Galactica's audience numbers to see if bad moments in the show drove audiences away.
The chart above shows Nielsen Ratings that measure audience numbers on the Y axis, and every episode of Battlestar by season and episode number on the X axis. (We left out the final two episodes, as that data wasn't in yet when we did the chart.)
One thing you'll notice right away is that the show's ratings decline very gradually, which is a normal shape for audience stats to take with any TV series. So that doesn't indicate that the show went downhill. It just means that most TV shows tend to shed audience numbers over a period of years. Another thing you'll notice, if you cross-reference with this handy episode guide on IMDB, is that many of the biggest audience spikes are associated with season finales and season premieres. These "event" episodes don't always reflect the trends we're looking for here.
So now there's the question of how you determine which episodes are shark jumpers. Obviously this is fairly subjective, but we did have at least one semi-objective measure. We ran a poll last year asking readers which episodes of BSG they thought were shark-jumpy. So three of the episodes we list above got votes from 500 or more people who thought they were shark jumpers. These were: "Epiphanies," (where Roslin was "cured" of cancer by hybrid Hera's fetus blood); "Crossroads, Pt. 2" (when Bob Dylan was in the cupboards and we learned who the Final Five are); and "He That Believeth In Me" (when Baltar founded a love cult).
Other shark-jumpy episodes were fingered by opinion-makers we polled informally at South by Southwest's Interactive Conference this year. These included "Collaborators," when Baltar went to live on the Cylon Base Ship, which many critics also agreed was a bad turning point for the show; and "Unfinished Business," the boxing episode which divided fans over the question of "good or ass." Pretty much everyone agreed that "No Exit," where we find out about Ellen and Cavil's icky relationship, was a stinker. And I personally threw in the episode "Kobol's Last Gleaming, Pt. 1," when crazy Roslin decides to get the Arrow of Apollo and stick it in the Temple of Athena, because it was a terrible low point in season 1. Just because a show recovers from a shark jump doesn't mean it isn't one.
So now to the actual question at hand: Did the show suffer when it jumped those sharks? If people were recoiling from a shark jump, you'd expect to see audiences decline or at least not go up after that episode. Not too surprisingly, nearly all the shark jumps were followed by such a decline or flatline. In fact, the only shark jumpers not followed by declines were "Unfinished Business," which many people actually didn't hate (so it might be an outlier example); and "Crossroads, Pt. 2," which as you'll recall was followed by the TV movie "Razor," which aired so long after Crossroads that it became an event episode rather than a strict follow-on.
As a result of our brilliant, semi-scientific research, I think we can tentatively say that audiences are in fact fairly reactive when a show jumps the shark. They immediately tune out the following episode, not even giving it a second chance for an episode or two. We also see that they will come back, however, especially if the show goes off the air for a while and returns with an event episode like "Razor."
CONCLUSIONS: Using Battlestar Galactica as an example, we've examined how audiences respond when a show jumps the shark. What we found is that a significant percentage of them almost immediately abandon the show for an episode or two. But then we see them returning again, often in larger numbers. TV watchers are more discerning than you might think, but only in the short term. They won't come back the following week if you serve them something that tastes like shark with jump sauce. But they might return to chow down in two weeks, and invite their friends along.
APPENDIX: Battlestar Galactica Nielsen Ratings By Episode (Compiled by Alyssa Johnson!)