It also depends on what style of play you want. Navy plays a conservative defense, perhaps even more conservative than Coach Ted Roof's scheme. The reasoning behind that is because Navy knows that if you get a high number of possessions in a game, the more talented team will generally win out in the end. With a bend-don't-break defense, Navy can artificially limit the number of possessions in a game and force opponents to beat them with efficiency, something that Navy has been incredibly good at. Two years ago, Navy held Notre Dame to only 6 possessions and won the game because of that. A lot of people forget that this type of defense - bend-don't-break - was lauded only a few years ago and claimed to be perfect when paired with our offense because it limits the amount of possessions in a game, and since we were one of the most efficient teams offensively we had a great chance at beating better teams, such as the Clemsons, Alabamas, and Ohio States of the world
Now, everyone is saying that an aggressive defense is the key and perfectly paired with our offense. I don't think that's exactly true. If you give up big plays and scores, then you put the offense in a hole that forces us to deviate from our base offense and requires us to air out the ball, which we've seen does not have good results. Frankly, I think a lot of the animosity behind Coach Roof's defense came from the fact that it wasn't fun to watch, in the same way many people hate Coach Johnson's offense. I think a lot of people want to see something more aggressive because it is more fun to watch. My philosophy is: the best defense is one that works. It doesn't matter whether it is conservative or aggressive, as long as it works