Never understood how can people be so temperamental to start a fight because someone talked bad about team you like. As if cursing or beating other teams fan would make any help for your team to win. I understand if someone starts a fight to protect family member or someone who is weak. But to start a fight because your team has lost.
Now on the topic. Shouldnt raise of gambling do opposite, increase violence ? I dont have any stats, but I think that people lose more bets and money than win. Whenever a person looses money, he isnt happy about that. Increase of gambling should me more money lost and that would increase the amount of unhappy and angry customers, ready to release their anger any second on any object or person. This should lead to two parties (those who won money and their team won, and those who have lost) conflict in sports viewing center. But, like I've said above, there is no reason for that, as violence wont return money or could make games final result different.