The revision to the cut blocking rules took away a lot of their cheap tactics.
You can't do cut blocking outside of the tackle box. Navy was very adept at diving at defenders' knees and ankles outside of the tackle box when the said defender was doing lateral pursuit.
Also, if you're not a lineman, then you can't cut block someone from the side. This takes away the blindside chop block. I call it a chop block, since the first Navy blocker would grab on, and hold the defender up high, while a second non-lineman blocker would dive at the defender's knees or ankles from the side, making it almost impossible to see at times, much less avoid.
Technically this wasn't chop blocking, since the high blocker would release a split second before the second blocker made an impact. This is what all but crippled Joe Schmidt in 2014, ended Eric Jones' career in 1991, left Bryant Young hobbled in 1991 against Tennessee and Penn State, and also hobbled Chris Zorch in 1990 for the Tennessee and Penn State games.
At least from the front, a defender can use some footwork to avoid the worst of the chop block part, since he can see the cheap shot being taken.
Now that it's illegal to do the above, Navy has had to resort to more conventional blocking, or God forbid, using clean cut blocking (where you aim your shoulder at the defender's hip or upper thigh).