I first saw It's Always Sunny in Philadelphia (IASIP) over 10 years ago and thought, "wow, this will be canceled tomorrow." I was wrong. Season 14 will tie IASIP with The Adventures of Ozzie and Harriet as the longest-running live-action sitcom in American TV history. What has made the show endure? What are some of the most popular aspects of the show? I took a quantitative approach to these questions and along the way confirmed some biases (score!).

I gathered the IMDB ratings, cast / crew info, and data from Fandom for each episode using SeekWell. Here's an outline of that process:

Now that we have a clean dataset, let's answer a few questions.

How has the show done over time?

IASIP is consistently popular. Although viewers rated season 7 episodes slightly lower and season 13 saw a slump in ratings, every season has an average rating of at least 8. The series average is 8.26.


Does the time of day / day of week effect the popularity of an episode?

Most IASIP episodes start with two titles showing something like "2:30 PM" → "On a Thursday".