This weekend, the Los Angeles Dodgers play host to the San Francisco Giants in a meeting of bitter divisional rivals. Indeed, as you may remember, the rivalry became so heated last season that it resulted in the death of Johnathan Denver, a Dodgers fan who got in a fatal altercation with Michael Montgomery—a Giants fan—while visiting San Francisco for a Dodgers-Giants series. 

Unfortunately, the violence that took place between Denver and Montgomery is one that is no longer unique in sports. Over the years, more and more of these incidents seem to appear in the headlines every season as bad blood and overly passionate fan bases mix together to form a deadly combination. 

It never has to be this way—after all, it's only a game. But, for whatever reason, too many fans over the past few years have decided to make wins and losses the reasons to form personal vendettas. In sports like soccer and baseball, these issues have reared their ugly head the most significantly. And as you'll see from A History of Fatal Fan Violence, it's an unsettling trend that needs to come to an end.