Redrawing the MiLB Map: An Update

On Monday, we published a piece detailing how MLB’s proposal to reimagine the minor leagues would alter in-person access to professional baseball across the country. We were interested in how many people would lose their ability to watch affiliated baseball in person, or see that access shift from the minor leagues to more expensive major league parks. To arrive at those numbers:

[W]e took the geographical center of each ZCTA (a close relative of ZIP Codes used by the Census Bureau). We calculated the distance as the crow flies from each ZCTA to each ballpark in America, both in 2019 and in MLB’s proposed new landscape. From there, we took the minimum of all of those distances for each ZCTA. That gave us the shortest distance to baseball for each geographical center. We then matched the distance with the population of each area.

In the piece, we acknowledged the limitations of linear distance. It doesn’t account for natural barriers, like say, mountains or lakes, or things like the placement of roads. And, as several folks pointed out on twitter and in the comments, not all road conditions are created equally. How long it takes to drive 50 miles in the Washington D.C. metro area varies widely from how long that same distance takes in rural Montana. What’s more, residents of those respective areas likely view a 50 mile drive differently; if you have to travel a ways to go grocery shopping, your understanding of how burdensome a 100 mile drive to your “local” minor league ballpark is probably different than it is for someone who lives in a place with a meaningful rush hour and amenities that are closer at hand. So while linear distance is a good approximation of how the access landscape would change in the new minor leagues, we wanted to take a stab at being a bit more precise.

First, we looked at a closer band. We looked at areas losing access to any level of professional baseball within 25 miles. For this variation (and only this variation), our map includes major league and independent teams. Our reasoning is that while a fan making a 50 mile drive is committing to a good deal of travel time and might reasonably prefer a very specific form of entertainment (a particular team, level of affiliated ball, etc.), a fan hopping on a bus or making a 15 minute drive to the ballpark might be more flexible, as their time investment is lower. The regions losing access to that nearby baseball look like this:

That more closely depicts the situation in New England and the northeast in general. It doesn’t handle the western half of the US all that well, though. To account for that, we also looked at a variable distance method. We assigned a maximum driving distance to each state to account for differing driving preferences. Montana, for example, has a 100 mile maximum, as populations and amenities are more spread out on average. Connecticut has a 35 mile maximum. Kentucky is somewhere in between, with a 75 mile maximum driving distance. This map, unlike the first one, only looks at minor league stadiums:

The number of people losing access to live baseball by these two definitions is still quite large. Depending on your criteria, as many as 16 million people are affected:

This method is still imperfect. It doesn’t account for variations within a region, as we are approximating travel distances with a broad brush. It doesn’t account for public transit maps; a 45 mile journey by commuter rail to a stadium might be completely acceptable, while a similar 45 mile journey not on the rail path might take hours due to traffic. We still can’t account for inefficient roadways and natural barriers, and we aren’t modeling the impact of traffic, the presence of which might inspire many a would-be baseball fan to stay home, no matter how close the park. But tolerable driving distances are contextual, and this new analysis attempts to account for that.

This map also assumes ready access to either a car, or workable public transit or bike routes, the latter two of which might be hard to come by, particularly in the rural communities Allison McCague highlighted in her piece at Baseball Prospectus. A 45 mile trip might be simple for someone who lives near a commuter rail or reliable regional bus line, while a 45 mile trip to the same park could prove prohibitive in a region with no access to transit. Transit access is an issue all its own, and one unlikely to be solved by MLB (though the league and its teams can certainly do their part by making easy access to public transit a priority in the selection of new ballpark sites). Still, we think is important to acknowledge, especially if we’re assuming a variable understanding of what is “close” when considering how accessible affiliated baseball is.

There are other, worthwhile avenues of research that have their own understandings of access, too. For instance, our initial mapping project accounted for minor and major league baseball facilities, as well as those of the Independent Leagues, but it doesn’t take into account college programs. That omission is defensible in an analysis of the access to pro ball, but the Vandy Boys might want a word with us. And you might also wish to build an even more nuanced version of the pro landscape, one that accounts for regions in a different way or considers different maximum driving distances.

Should you wish to perform further permutations, you’re in luck. If you’re comfortable with our three choices of stadium set (MiLB, MiLB/MLB, and all pro ball), you can look at the raw data for population and distance to baseball here. This dataset is the output of our minimum distance algorithm for each ZIP code under those three conditions, and accounting for the proposed stadium closures. If you’d like to add your own stadiums, you’ll need to recalculate the minimum distance yourself, but you can find the longitude and latitude of each ZIP code in the linked dataset, and our own database of approximate longitude and latitude for all professional stadiums here. From there, you’d merely need to add the extra stadiums and re-run a minimum distance algorithm on your new data.

We’re glad to have the opportunity to refine our work, and hopefully help others with theirs. As MLB and MiLB contemplate the future of the minor leagues, there are a lot of questions that have to be answered. We hope that this piece brings a bit more precision to this one.