Who are Boston’s Most Loyal Sports Fans?

Boston is renowned as a sports city, with legendary teams such as the Boston Red Sox, Boston Celtics and Boston Bruins. Each team has had very successful periods and also poor ones in terms of winning games. Using Python’s Matplotlib library, I wanted to see which Boston fan base is most loyal to their team in good times and bad.

Code and data for this project are available on my GitHub page 

This project is more or less an excuse to get acquainted with Matplotlib. I wanted to create a nice, intuitive graphic that takes advantage of Matplotlib’s flexible framework. The research question which motivated this graphic was to determine which of fans of Boston’s main sport teams were the most loyal. I realize this question can be solved a multitude of ways, but for this post I wanted to focus on the visualization and not go too in-depth into the analysis. Unfortunately, I could not include the New England Patriots in this analysis because there was insufficient data.

The chart assesses fan loyalty in two ways. A simple histogram at the top demonstrates the variability of the average crowd size for each team for a given season. Crowd size is given by the variable “Capacity Filled” which is a ratio of how many available seats were sold on average per home game during a particular season. This helps to account for the fact that each team has a different crowd capacity for their respective sport. On this basis, it appears that the Boston Bruins have the most loyal fans since they consistently sell a high percentage of their seats on average each season.

However, the bottom charts compare the relationship between “Capacity Filled” and the matching season’s winning percentage. A line of best fit is calculated to visualize the correlation between fan attendance and winning. While Bruins and Red Sox attendance is very positively correlated with winning, the Celtic’s correlation is actually slightly negative. The main reason for this is that during most of the 90’s (‘93 onwards), the Celtics averaged a dismal winning record of .378 but still maintained an impressive 95% of seats sold. This suggests that Boston Celtics fan attendance is not sensitive to how the team performs, and therefore Celtics fans can be classified as Boston’s most loyal fan base.