Can't let the animals run the zoo.
I have yet to have a player score from the bench. It is absolutely within the power of every coach to limit the amount of goals a player scores. If 3 is the rule, it is amazing how they start passing after two to make sure that 3rd doesn't cut their playing time off. It really creates players who work together, and they look for that kid who hasn't scored when the game is 2-0 or 3-0 instead of 15-0.
Very few soccer games are won after someone is down 3-0, and in reality almost none after 2-0. If the zookeeper lets all of the animals know the rules, and puts them in the proper place in the zoo to keep the rules in place, the zoo runs pretty well.
Don't send me a bunch of emails about animal rights, "players aren't animals", etc. Please.