37. Tyrann Mathieu, S, Cardinals
There's a lot of discussion as to whether Mathieu is a better safety or slot cornerback, but the point is moot, because he covers both positions so well. More than that, though, he's a force multiplier in James Bettcher's defense because he's a rover in the truest sense of the word. From tracking receivers in man coverage across the formation, to pattern reading slot receivers up the seam, to blitzing off the edge, to converging in zone coverage and helping over the top as a center-field defender who has the raw speed to keep up with any receiver in the league, there isn’t much he can’t do. What Mathieu may do best (and what the Cardinals allow him to do that other teams might not) is to guess right in the open field. He'll bait receivers and then close to pick off passes. He'll play off-coverage and move in for a tackle with very bad intentions. And if you're taking a slant across the field with free space in front of you, then you better keep your head on a swivel, because the Honey Badger is coming fast, and he don't care. That bold style leads to the occasional coverage lapse (he gave up five touchdowns last season, per Pro Football Focus), but his team will gladly deal with the occasional negative effects of his playing style because he's utterly unique in his positional versatility and complete commitment to whatever it is he's doing on the field.
