Between The Posts: Defensive Improvements?

The Tennessee Titans focused on the offensive side of the ball, and much of the talk, thanks in part due to Marcus Mariota, has been centered around that side of the ball. I actually like the front office's strategy here. While the team has been criticized for ignoring a defensive squad that underwhelmed in 2014, focusing on making one side of the ball dominant is an attractive option, especially considering that many of the league's top-performing teams have done just that. That said, Whisenhunt and co have a lot of work to do to make the Titans offense feared to any degree.

The Front Office seem to be comfortable upgrading the defense primarily through free agency. Brian Orakpo, Da'Norris Searcy, and Perish Cox are all clear upgrades over what the team trotted out last season, and that's even true if we grade them as simply 'average' when the 2015 season is in the books. Which addition to the defensive roster do you think will make the biggest difference this season.