By now, you’ve very likely seen the New York Times’ “A Map Of Baseball Nation“, which suggests pretty strongly there’s nowhere in the continental USA or even the state of New York that could be considered Metsville. Amazin’ Avenue’s Matthew Callan takes a dim view of the Times’ exercise, citing the Grey Lady’s reliance on Facebook Likes for allegiance data (“tell people you’ve based a supposedly scientific assessment on anything Facebook related and you might as well hand out investment advice based on Magic 8 Ball responses”)

The problem with basing a visualization on Facebook Likes is that the Like has no value as an indicator for level of enthusiasm, for any endeavor. When you click that you “like” something on Facebook, that Like stands in for an enormous gamut of emotions, ranging from I Guess It’s Okay all the way up to I Will Die For It.

When someone’s Facebook profile says they “like” the Yankees, all we know really is that person doesn’t hate the Yankees. We don’t know if this person could name anyone on the team other than Derek Jeter, or if he/she watches the games with any regularity. “Liking” requires no commitment. It asks nothing of a person but a nanosecond of their time. It’s impossible to say how a Like serves as an indicator of a team’s “real” fans. This would probably be even more true in one-team regions, where a person might click Like for a team out of pure civic pride while possessing zero affinity for the sport that team plays.

We also have to look at how this map declares its winners. In this regard, it is closer to an electoral vote map than a popular vote one. A team wins all of a zip code by taking a simple majority of the Likes in that zip code. Just like in a political election, how many people didn’t vote at all is irrelevant to the result; it’s winner take all whether everyone casts a ballot or one lonely guy does. Knowing 40 percent of the Facebook Likes in a certain area favored a certain baseball team doesn’t tell us how many people in that area don’t care for baseball at all. For all we know, the results could be skewed by a hardcore group of fanatics fulminating amid a sea of baseball apathy.