All these Baseball and American Football rivalries pale into utter insignificance when compared to the dark years of British football hooliganism in the 80's & 90's.
Or Rangers/Celtic now!
But the sectarian violence between Rangers and Celtic fans is, at it's core, more about religious divisions than football rivalry. The organised football hooliganism from the 80's and 90's in England was all about the rivalries between football clubs, and which club had the hardest Firm.
And don't talk to me about Rangers fans. I'll never forgive those fuckers for trashing Manchester city centre a few years ago. Now, because of them, we Mancunians can't even watch football games on the big outdoor screen in the centre of our own city.