A hallmark of a Pat Narduzzi defense is being disruptive upfront. Not simply being able to stop the run, but penetrating in the backfield to keep pressure on the quarterback whether simply dropping back or those running the option or spread. The linebackers are going to play closer to the line, and look for chances to make plays up-front rather then contain.
The risk to his defense is that it also leaves the corners on an island with little help. It’s one of the reasons Pitt was so bad against the pass and led the conference in surrendering passing plays of 20 yards or more.