His defense was quite effective in Indy. He has produced two top-10 units in total defenses, six top-10 units in rushing defenses, four top-10 units in scoring defenses and four top-10 units in turnovers created. His defenses weren't as effective in Chicago but my understanding is that they did better when he took back over the play-calling. We'll see how it works here. Because of Marinelli, we have reasons to be hesitant about the Cover-2 scheme, but there are teams (Tampa and Indy) that got it right to the point that it helped them win Super Bowls. Lovie Smith's version of it in Chicago also was pretty effective. Kiffin wasn't able to replicate its success here, though, and neither was Marinelli, so we'll see.
Most likely, how effective it is is going to come down to personnel, and I fear that's where we will fall short since our front office rarely gives its coaches the personnel it needs. We'll stumble across a few difference-making players like Parsons, but then put nothing around them to help maximize their effectiveness.