It's been "bizarro world" in Chicago, where the Bears headed into the offseason with a relatively stable offense but question marks all over the defense, reversing a near annual trend that usually involved offensive uncertainty and a trust in the defense.

Whether it was trying to stop the run, rush the passer or cover the pass, the Bears failed miserably on the defensive side of the ball in 2013. Using just about any form of measurement, the defense was one of the league's worst, but they've made a number of moves to ensure that won't be the case again in 2014. Let's take a look at them, and see why the improvements should be enough to vault Chicago into NFC contender status this season.

Weak at every level

The search for positive grades on the 2013 Bears defense comes up empty, save for a plus-0.4 overall grade for Lance Briggs on his 565 snaps and a plus-0.3 overall for Tim Jennings.