Discipline in practice and in a player's studies are important, but that's not the kind of discipline I'm talking about here. I'm talking about the kind of discipline that prevents penalties.
Penalties against an offense in football are usually very forgiving. False starts, a five-yard penalty, and holding, a 10-yard penalty, can sometimes be tough to overcome, but they're manageable and can sometimes prove to be irrelevant (such as when the team ends up scoring).
Defensive penalties, however, will more often than not give the other team a fresh set of downs. That gives them a greater chance to score and ensures the Tide's offense starts closer to their own end zone.
Roughing the passer, face mask, horse collar, helmet-to-helmet and the list goes on. For Alabama, however, the defense rarely gives the other team free yards.
One has to look no further than the 2012 BCS National Championship game for the perfect example.
Alabama had one single penalty throughout the entire game. You would think Nick Saban was happy with that, but during the game, you could see he was completely irate that a penalty was received. He wasn't mad at the officials, but mad at the player.
He stresses it not just on the field, but in practice as well. The Crimson Tide play a clean game throughout.
No opposing defense will get a free ride to the end zone because no Alabama defender will lose his cool and go all Ndamukong Suh on the other guy.