Plugging the Holes: AFC North

Troy Polamalu's health could be the key to the entire AFC North. Rich Gabrielson/Icon SMI

Football Outsiders continues its "Plugging the Holes" series, in which it targets the offseason issues facing each team in the NFL by division.

Previous editions: AFC West | NFC West

Baltimore Ravens: Is there trouble ahead for the defense?

"Trouble" is a relative word, especially since the Ravens' defense isn't about to resemble the Lions' anytime soon. But some negative trends in 2009 need to be addressed in the offseason. Football Outsiders' DVOA metrics had Baltimore as the third-most-efficient defense in the NFL and seventh against the pass. But a closer look reveals that much of that pass defense success came from the excellent play of the linebackers and safety Ed Reed. Baltimore was the best team in the NFL at shutting down the opponent's tight end, and third best at defending passes to opposing running backs. Wide receivers had much greater success, with the Ravens ranked in the middle of the NFL pack. Some of the trouble against the pass can be attributed to a decline in the front seven. Baltimore's Adjusted Sack Rate dropped to 23rd in the NFL, although the defense was still stout against the run.