I'll play devil's advocate here a bit. The idea that the NHL fundamentally controls fighting in the league is not true. They have the control to discipline players as per the CBA, but if the fighting isn't criminalized, then it's just two people going at it and that's consensual and not illegal. What mechanism do they have to control fighting? Harsher monetary penalties, suspensions, and the precedent for such. But that's it. This is why referees/linesmen only break up the fight when it's tilted or when it's gone on for a while; it's safer for them to intervene if the fight is essentially over, and the referees aren't trained officers. I believe the penalties for fighting are also part of the negotiation with the players' union, so until the players want the fighting out of the game it probably won't happen. The compensation for having fighting in the game? MONEY. YOU MAKE MILLIONS. Take fighting out of the game, you take money out of the game, and you take money away from players (both in terms of hockey-related revenue and in future negotiations).