Giants vs Dodgers is probably still the most violent rivalry's in American sports if they stayed in NYC wow
It’s bad enough when they only share a state - a Giants fan got beaten into a coma by some asshole Dodgers fan/fans a few years back. That becomes an annual occurrence if they both stay in New York. Throw in the Yankees and it gets a bit more out of hand.
Which brings up another point - not only are American cities and teams more spread out (name ANOTHER league outside America that has to deal with FOUR time zones and have teams regularly cross a Goddamn CONTINENT...the CFL doesn’t count) but leagues are set up in such a way that crosstown rivalries aren’t much of a thing. With the exception of a few massive cities, it’s one team to a metro area here, and in those large cities, you don’t get enough bitterness - or the opportunity for it - to justify anything close to rioting. The Mets don’t play the Yankees enough for it to be anything more than a novelty. The Dodgers and Angels don’t give two shits about each other. Chicago has potential, but the hate seems to be one-sided - Cubs fans kind of look down their noses at the White Sox, and even Sox fans don’t rise above bitterness (though there’s plenty of that - Obama’s biggest lie as President has to be when he said he didn’t hate the Cubs. I’ve been to Sox games and seen firsthand how hated the Cubs are and I know he was full of shit.) But even that isn’t enough for rioting.
Really, the only fandom in America that has any potential for hooliganism is college football, and someone pointed out earlier that the cops would stop that in its tracks. Even incidents like when some fuckheads poisoned Auburn’s historic trees were met with unequivocal condemnation from even Alabama fans and officials. Rioting and hooliganism would not be tolerated.
Even at the smaller levels, it’s not tolerated. I attended Ohio University in the early 2000s, and the hockey fans were the closest things we had to hooligans and even then they were barely a 2/10 on the hooligan scale. All they did was come up with edgy chants and curse a lot (after every OU goal, the fans all united in a chant of “We’re gonna kick the shit out of you, and your mom, and your dad, and your girlfriend too!”) At one point during a heated game with Penn State (a rival to OU at the time...and if I may be serious for a minute here...fuck Penn State) a couple of OU fans started shouting racial slurs at a Penn State player (I think the player was Asian, but I don’t know and it doesn’t matter; I wasn’t at the game and heard about it secondhand.) Everyone not only condemned it but trended into “overreact” territory, telling the fans to cut the off-color chants that included the word “shit.” Fortunately the slurs stopped and the run-of-the-milk profanity did not.
Hooligan culture just isn’t there and there are too many things working against it, including that Americans don’t seem to live and die with a particular team in a particular sport. In Europe, it’s always been all about soccer first and foremost, and everything else is just details. In America, fandom has evolved and is far too regional and often all over the place, and rivals evolve from incidents and not familiarity breeding decades of contempt, and then such rivalries dissipate when there’s no reason for them to keep up.