The Pittsburgh Steelers have certainly had some great defenses during the Super Bowl era and four of them wound up making the 30 best of the last 30 years rankings that Aaron Schatz of Football Outsiders put together for ESPN.com.
Schatz’s rankings are based on Football Outsiders’ DVOA (defense-adjusted value over average) metric and coming in at No. 30 overall is the 2004 Steelers defense with a DVOA of -18.6% and Schatz writes of that unit:
Pittsburgh has ranked No. 1 in defensive DVOA five times, more than any other franchise during this 30-year time frame.