Lunatic theory that seems to make more sense than it should.

While watching Fox Sports Pittsburgh, I noticed they're running this ad for eHarmony, where they show a happy couple reflecting on how there's no way they should have gotten together because he's a Steelers fan and she's a Browns fan. And while they talk about how happy they are, I just keep waiting for the guy to respond to one of her statements with "Yeah, you just keep talkin'." (Yeah, it's the ESPN ad with the Ohio State and Michigan sweatshirts necking, and the caption "If it wasn't for sports this wouldn't be disgusting" all over again.) S'anyway, I just want to file the data away that for when this pops up on the news, a double homicide involving creative use of a towel and a rawhide bone. If it doesn't they're not that passionate fans of the teams and we don't need to see this ad.

And then the mind makes another jump, where could this happen? Certainly not in Cleveland, not in Pittsburgh, it's just too explosive a mix. The only way I could see it working, other than them being both ridiculously displaced from point of origin, is if it's in Youngstown or Sharon (the traditional border checkpoints between Steelers Nation and Browns Nation) And of course that sort of violence is naturally suppressed by the mob's presence there.

So that gets me thinking: For every firmly established rivalry between teams within driving distance, (Now I mean both really nasty, and lasting 50 years or more), does their exist a traditionally mobbed up area which serves as an impulse control buffer zone? The more I looked at the data, the more sense it made. Giants/Eagles and Giants/Redskins have New Jersey. Yankees/Red Sox have Rhode Island. They kept lining up. The only one I can't work out is around Chicago, because I don't know the geography there if there's a preferred direction of bad towns exiting the city. If it's uniform around the city, it solves Bears/Packers, Bears/Lions, Cubs/Cardinals, but I can't determine.

So here's the thing, I recognize it's a completely crackpot notion, and I know it's probably two completely different sets of data that just happen to line up on maps, but I need the counterexample. Can somebody please give me a counterexample?