Infographic: The major characters and themes of every Simpsons episode

If you're a fan of The Simpsons as we are, chances are you've been watching the "Every Simpsons Ever" marathon on FXX starting last week. Although the show's golden era was mostly over by Monday—and of course the marathon will continue through Labor Day—one can't help but admire how the show remains a juggernaut at the quarter-century mark. With 552 episodes, hundreds of characters and numerous recurring themes, we got ourselves wondering: what would it look like if we tried to identify each episode by type? How many were focused mostly on Homer? How many on Bart? Which background characters have moved to the foreground most often? Has there really been a Treehouse of Horror every year since it debuted in season two?

The answer to these questions and more are found in the graphic below. We counted every episode, debated among ourselves whether "Who Shot Mr. Burns (Part Two)" belonged to old Monty or perhaps to young Maggie; whether episodes with a lot of Edna Krabappel more properly belonged to Bart or, more recently, Ned Flanders; and if one episode was better categorized as a Christmas episode or a flash-forward one. Here's what we came up with:

Yes, we gave part two of The Simpsons' "Who Shot J.R."-inspired cliffhanger to the Simpsons' youngest child; Mrs. K was often a foreground character but the story arc usually focused on another character learning a lesson; and "Holidays of Future Passed" is both, but there are fewer flash-forwards overall, so we figured that was the way to go.

Here's a bit more insight on how we made the difficult decision of assigning shows to just one category or another: Clip shows, "The Simpsons Go To", Treehouse of Horror and other themed episodes were given top priority. Of course some of these may focus on Bart ("Bart vs. Thanksgiving") or Lisa ("I Love Lisa") but their holiday theme carried the day.

Where no such factors were present, we focused on which character seemed to be central, or had the most screen time (not that we did this with a stopwatch, mind you). Where this was not obvious, we went with the character who learns a lesson at the end—the character whom the story arc finally settled upon. This was not so easy, especially in the series' madcap later seasons, where cohesive stories were arguable at best, sometimes arguably elusive.

Occasionally, we went with the character who kicks off a story not focused on any character ("Bart vs. Lisa vs. The Third Grade") and occasionally a one-off character who dominated where no one member of the family does is chosen (hence we gave "Simpsoncalifragilisticexpiala(Annoyed Grunt)cious" to Shary Bobbins but Frank Grimes didn't get "Homer's Enemy"—that was still a Homer episode).

In many cases, a show could be conceived as both (such as "The Italian Bob", which is both a Sideshow Bob and a Simpsons Go To episode). Same with "Holidays of Future Passed". Typically, we chose the less common designation, figuring this was the more notable.

And if you disagree with anything above, please know that we anticipated your objections ahead of time, considered alternatives, and asked ourselves: "Can't someone else do it?"

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