Despite the headlines each of their offenses continue to receive, I believe the Green Bay and Pittsburgh defenses are huge reasons why these teams can make extended runs during the postseason. Each unit has righted the ship after some midseason struggles to re-emerge as solid units. The Packers have held their last three opponents to 12 points per game and helped the team enjoy a plus-7 margin in turnover differential. Although their pass rush hasn't heated up to this point, the presence of Clay Matthews and Julius Peppers off the edges is sufficient enough to disrupt the timing and rhythm of a quarterback attempting to lead a late-game charge from the pocket. The Packers are 7-1 this season when allowing fewer than 30 points. With an offense that's returning to form, Green Bay's D doesn't need to be dominant to engineer a run -- just steady.