I think that the "lack of a pass rush" thing is just an easy term for the uneducated to throw out there. ... If you have the speed to get to the QB, you can actually send people. Scheme can compensate for lack of an elite edge rusher, and we are seeing more and more blitzing from this team. This is indicative of the players getting what the coaches are trying to do, and the coaches trusting their players ability to reach the QB.
Let's consider pass protection schemes. At it's most basic, pass blocking schemes are set up as a "mug" protection. Often, you hear the "cup" protection, but it is more of a "mug". Cup protection forms a semi-circle pocket, mug protection has the guards and center staying more stout in their protection, as the tackles bring the ends upfield. This facilitates sliding much better than cup protection schemes. Too much emphasis is placed on edge rushers simply beating a tackle, end, or back (usually a combination) and getting a shot on the QB as he hits his hitch step. Largely, Belichick was responsible for this line of thought with the way he utilized the real LT. It really is much more than that, though. Pass rush is primarily about taking away avenues of escape. Be it sliding, throwing lanes, or hot reads, the rush needs to take these away to be effective. As an example, take a look at the best pocket slider in the NFL, #12. He is extremely tough to get after because he understands where the pressure is coming from, where in the pocket he can move to, and where his help is. When Brady is pressured effectively, teams understand how he moves. He has an initial slide, usually caused by an edge guy getting upfield. Brady then slides towards the B gap and uses the forward momentum of his step to deliver a strike either downfield or to a zone vacated by an extra rusher. When he is taken down, the defense beats a guard or center and puts a guy directly into the slide. This is accomplished by interior rush. The inverse of this situation is also true. Inside rush can also flush a QB into an end. We are seeing this type of complimentary pass rush from the Patriots recently. They understand how QB's move in the pocket and take advantage of it. The safeties and ILB's are becoming highly proficient rushers, and it is showing more and more on the field as the inside rush becomes a halmark of this Patriots team. Yes, they do need an elite edge guy to create a true swarm, but they are compensating quite well.
