In my Digital and Social Journalism class at SUNY Oswego, I am teaching a unit on data journalism and data visualization. So I thought I’d share a series of my favorite sports data visualizations and why I like them.

Another lifetime ago, I interviewed for a job at a suburban Chicago newspaper. The editor and I were talking on the phone and sharing potential story ideas this reporter might do.

The editor had an idea for a feature story he always wanted to do. He wanted to find the line of demarcation between Cubs fans and Cardinals fans. He envisioned a reporter driving southwest from Chicago and asking people what their favorite baseball team was until they found the border of the midwest’s biggest baseball rivalry.

I didn’t end up getting the job. But that story idea stuck in my mind, and it came back when I saw this piece from the New York Times in 2014.

This is the value of using data in journalism. Instead of driving Southwest, randomly interviewing people until you have an anecdotal sense of where a border is, the data from Facebook gives you a concrete location.

(The answer, for the record, is a little south of Peiroia, Illinois).

The map allows you to find the most popular baseball team in every Zip code. It’s a fascinating visualization, one you can spend hours on.

But it’s also the starting point for some fantastic journalism. Now that we know the borders of baseball’s biggest rivalries, we can go there and tell the stories of the fans who live there.

It’s a reminder that data visualization and data journalism is never a means to itself, but can serve as a way to illuminate and contextualize our world.