This can be very effective if you want some pressure and you want the middle of the field covered up. The top safety is in a yellow zone which is covering up post routes. i would move your corners in blue zones up where your top safety is to cover the flag routes. Pinch your linebackers and if you have a fast LB, he can get through or cause havoc on the line which my cause more pressure. This is a good defense to use against the run as well if you are having trouble stopping offenses under center. Pending on your opponent, this will work most of the time.