Ballpark Figures: Analyzing MLB Baseball Attendance

It is summertime in the US, which means something as American as apple pie is in full swing: baseball. And since there’s all kinds of great data around one of the country’s great pastimes, we decided to analyze Major League Baseball (MLB) attendance statistics from the last 22 years. These numbers are published on many websites including the one we used to get the data you’ll find in the charts below: ESPN.com.

Explore the data below, plus a few observations from us.

The missing stats from 2020

The first thing you’ll probably notice is the attendance dip between 2019 and 2021—and the fact that we have no data for 2020, the year baseball was played without fans. The 2021 data suggests a bit of a return to normalcy, but you’ll see it wasn’t until 2022 that all spectating restrictions were lifted and attendance returned to pre-pandemic levels.

Comparing attendance pre- and post-pandemic

One question we asked ourselves is whether Attendance By Year changed after the pandemic. In other words, did COVID appear to have an effect on people’s willingness to head to the ballpark, and has attendance rebounded since then? To answer, we looked at average attendance in 2018 and 2019 compared to average attendance in 2023 and 2024.

Overall, MLB attendance after COVID has inched up slightly by 3% from 28,592 to 29,436. This is still a far cry from the later 2000s, when the league average was over 33,000 for a couple seasons. Of course, not all teams have seen attendance rebound post-COVID. Fifteen teams have seen attendance decline led by Oakland (-45.4%) and Washington (-20.5%). Also, I’m not sure if we can count the LA Dodgers, who were down .1% and still maintain the highest average attendance in the league.

The batter’s box (and whisker)

One good way to review this data is with an old favorite of many data scientists: a box and whisker plot. The chart shows the minimum and maximum average attendance for each team in the whiskers (the top and bottom lines). I’ve sorted this to show the team with the highest peak attendance year on the left, and the lowest on the right:

Where the visualization gets more interesting for me is with the box elements. Each box shows the space between the 25th and 75th percentiles, which is meant to reflect how much a team’s attendance has swung over the years.  

The bigger boxes tell me those teams (such as Philadelphia, Toronto, and Miami) have had some great years for attendance and some not so great years. Smaller boxes (such as Boston and the LA Dodgers) say that a team has been very consistent in its attendance numbers. We have also filtered the chart for pre-pandemic years only, because 2021—and, to a lesser extent, 2022—skews the data.

Explore the Major League Baseball app

One of the things I love—and also at times find maddening—about exploring new data is that there is always more to explore. As I worked on this post, I realized that it would be quite interesting to bring in teams’ win/loss records as well as information on stadium capacity. But then I thought: Let’s maybe save that for a future post.

Use the filters in the app below to customize your exploration of MLB attendance trends by league, division, team, or year. We hope this interactive experience helps you uncover new insights and enjoy the season even more.