Sports are the modern replacement for war.
People’s sympathies and loyalties to a team have come to replace the loyalties that people felt in the past towards their nation; and the passion, outrage or joy that is evoked when a team wins or loses a game is the same as what people in olden times experienced when a nation won or lost a war against another nation.
Different teams have different ideologies, ways of training, histories… Teams can be endowed with cultural identities just as nations can.
However, war nowadays–modern war–is something that evokes totally different (and more complex) sentiments in people.
But sports and sporting events evoke the same type of feelings that war did in the past, when battles took place mostly man-to-man.
It’s almost like a re-enactment of past events. A Karmic re-enactment of the feelings evoked by war that people have brought over from their past lives.