Brad Templeton, chairman of the Electronic Frontier Foundation and more importantly, science fiction-related blogger, has a long blog post which is going around the Internet about how the finale of Battlestar Galactica is "The worst ending in the history of on-screen science fiction." I cannot disagree with the premise, nor the massive amount of detail he includes in the post. However, I do think that the post's narrow focus on the massive mistakes of the final episode distracts from a larger, perhaps more interesting point: Battlestar Galactica's form of storytelling made it almost inevitable that the finale was going to be a disappointment.
The BSG episode form was built to increase dramatic intensity. Most television shows built their episodes as stand-alones, which include enough exposition at the start to explain their universes so that anyone can jump in and understand. This is often combined with references to the rest of the setting, so that they also can increase long-time viewers' knowledge of how the universe works. The storyline focuses on a handful of characters each episode, generally with two stories, a main A story and a secondary B story. The A story generally has the more important characters doing somewhat expected things, while the B story often has more intense, comic, or experimental things going on. The characters involved in the two (occasionally three) stories can intersect, but the themes almost always intertwine. The episode's storylines are resolved by the end of the episode. This familiar, procedural format tends to make surprises fairly unlikely.
Battlestar Galactica took a more fractured, ensemble-based form. Instead of each episode having a self-contained story, each episode tended to have one storyline specific to that episode, and a little bit of everything else shown in pieces. The most obvious example of this is the first season's story of Helo and Athena on occupied Caprica. Every episode in the first season had a few minutes worth of this storyline, which was totally unconnected to anything else going on in the series until the very end of the season. There was no particular reason why this couldn't have been done entirely in a single episode. Likewise, virtually every episode in the first season also had something about Tigh's alcoholism, the Chief's relationship with Boomer, Apollo's relationship with Starbuck, or Roslin's cancer.
By focusing on every character at once, the storyline became fragmented. These fragments do two things to a storyline: 1) they ratchet up the intensity, and 2) they make strong resolutions unlikely. The best parallel for this comes not from television, but instead from fiction, particularly the epic fantasy mega-series such as The Wheel of Time or A Song of Ice and Fire by Robert Jordan and George R.R. Martin, respectively. Both of these series are built around narrative shock after narrative shock, a massive, world-shaking climax at least once per book, characters consistently dying (and then being resurrected - sound familiar?).
The books are massive - usually between 700-1000 pages, largely because they often have ten or more point-of-view characters, who often take part in, or discuss, the same events. The POVs change with each chapter, often ending with semi-cliffhangers, leading to a narrative intensity based around one character being in mortal danger, another about to receive an incredibly important piece of information, a third falling in love, while the one you happen to be reading about is doing research in a dusty library. It's a great way to maintain reader interest; a fantastic method for having large books with lots of sequels; a brilliant plan for creating a detailed, well-populated setting; and most importantly, a guaranteed, sure-fire method for being totally unable to finish a story well.
The essential problem with the fractured-POV approach, which both Galactica and the fantasy mega-series have, is twofold: first, it forces the writer to come up with situations of increasing intensity to hold the viewer's attention (Tigh has sex with Caprica! Gaeta turns evil and sings! Boomer turns evil and doesn't sing! Adama becomes an alkie!); and second, the increasing complexity and intensity leads to one of the greatest banes of serialized storytelling, the "retcon."
Retcon, short for "retroactive continuity," is a device by which the writer of a story changes an explanation of what happened in the past in order to tell the story they want to tell in the present. It's most common in comic books, which have their decades of plots, deaths, and resurrections. Perhaps the most famous example is the X-Men's Dark Phoenix Saga, in which Jean Grey becomes so powerful that she goes insane and threatens the universe, and ends up committing suicide. A few years later, writers wanted to bring Jean Grey back, so the storyline was retconned so that it wasn't her who became Dark Phoenix, but rather...well, I'm not really sure, but it was some kind of clone/embodiment who was like, but not, Jean Grey.
Retconning can be used in ways that benefit the story. The Warcraft video games, for example, began as virtually plotless strategy games, but as they progressed, they've become incredibly detailed complete universes. In order to make the detail of later games make sense, the storylines of the original games have been retconned to be filled with relative details. Retcons can also be used to explain apparent mistakes by the writers.
However, in general, retconning simply makes it look like the writers are making it up as they go along. They're changing the rules, and if they change the rules, the storyline loses emotional impact.
Battlestar Galactica, from the middle of the third season until the end, had a storyline which was dominated by retconning: the "Final Five." The problem which created the Final Five was simple: by the end of the New Caprica storyline, we'd seen seven Cylons, with no particular reason why we hadn't seen the last five of the promised twelve models. So Moore created an explanation: the Final Five were special, and not spoken of. Which is fair enough. But then Moore had to ratchet up the intensity. So several major and minor character were retconned into being Cylons. The history of the Cylons themselves was retconned into existing before the war against the Twelve Colonies 40+ years before. And the entire storyline of the show changed from a complex examination of the ethics of leadership in desparate situations and whether humanity deserved to survive into a simple good vs evil struggle, where one evil Cylon with mommy issues tries to destroy all humans and most Cylons.
And now comes word of the ultimate in retcons, the TV movie "The Plan," which is supposed to totally explain everything that the Cylons did at the start of the series, according to the crap that the writers made up at the end.
By the end of BSG, the show was almost completely different from its stellar starting point. Consistency, both in storyline and in characterization, had been thrown out the window. Is there any wonder, then, that the ending was a crushing disappointment? The methods that Battlestar Galactica used to maintain interest and build intensity were, just like the fantasy mega-epics, initially thrilling, but eventually tiresome. This kind of storytelling is the rough equivalent of a microwave dinner. It's fast, it requires very little work, and it's edible. But it's not likely to be anywhere near as good as a meal made with care.
So how could Battlestar Galactica have done better at unfolding its story? There are several other TV shows that may provide some kind of answer - a subject for a near-future post.