It doesn't take just the playoff or finals to exhibit schools spirit. It doesn't even take school rivalry. THIS creates the school spirit that is so prevalent at HS soccer events. IMO I see soccer games more reactive than in football games, because of the amount of subject decisions regarind fouls and infringements. Now think of soccer.
All infringements are immediately on the play.
A foul almost always occurrs in the vicinity of the ball. So everyone is watching the same thing, the same players, the same incident. This makes soccer a more exciting spectator sport, and can go the negative way. This is usually one or two players. Sometimes the boys teams hang around during the girls games and they get a little roudy.