John Parolin of ESPN Stats & Information writes that the Patriots' epically poor regular-season defense has improved considerably during their postseason run to the Super Bowl:
A cursory glance at the New England Patriots defense paints the unit as everything from mediocre to historically bad. It gave up 411.1 yards per game in the regular season, the highest total of any Super Bowl participant in history.
New England ranked 31st in the NFL in both passing yards and total yards allowed, and also gave up a league-high 22 touchdown passes in the red zone this season.
However, the Patriots’ defense has been a different unit this postseason, allowing only 325.0 yards per game and improving in a number of statistical categories.
Some of it can be attributed to opposition, but the impact of personnel continuity can’t be overstated. For much of the season, the Patriots defense was without linebacker Brandon Spikes and safety Patrick Chung.