The Pittsburgh Steelers defense has seen a drastic transition in philosophy and scheme since Dick LeBeau left for Tennessee and Keith Butler took over as the defensive coordinator. Under LeBeau the team remained a 3-4 defense, who ran sub packages, like the nickel and dime defense, when the offensive deployment called for such a change.
When Butler took over, he and Mike Tomlin began sculpting a team which was based on the sub packages, moving to their base 3-4 defense on rare occasions during games. Becoming more of a zone coverage defense, the Steelers focused on rushing only 3 or 4 players with regularity, while dropping everyone else into their unique coverage schemes.