“While Pennsylvania only has two teams, the state’s team allegiance is split across seven different teams.”
There are some good geographic concepts that can be used by showing this map (based on SeatGeek purchases). In this related map of baseball fan regions (based on social media connections), we can see more clearly the value of the core-domain-sphere model. This map uses the brightest color intensities to represent the core regions and the lightest hues to show waning strength, but to still signify that the area is a part of a team’s sphere of influence. Essentially, this map is begging you to explore the borderlands, the liminal “in-between” spaces that aren’t as easy to explain. What patterns do you see? Explanations?