For the life of me, I can't understand why.
Let me back up and concede that Arrington's reputation as a subpar cover corner precedes him. But while he had his share of struggles early on this year—and what member of the Pats secondary didn't?—that reputation also precedes reality.
Arrington has bad habits—including his occasionally maddening refusal to get his head around on balls in the air—but no player is perfect. He improved steadily over the course of the season, such that by the end of the year his skills as a strong cover corner were hard to ignore.
The numbers bear out Arrington's improvement in the second half. After a first half in which he allowed a 76 percent completion rate and 11.7 yards per attempt, Arrington yielded the lowest completion rate (43.8 percent) of any player in the Pats' secondary (all stats per Dave's Breakdown, a great source for charting Pats secondary stats).
The eye test yields the same results. ProFootballFocus' evaluation metrics grade Arrington positively in eight of the last 10 weeks of the season (including playoffs) after a first half in which he graded positively in just four of the first eight weeks.
Not Just a Slot Corner
A lot of people attribute his improvement to his move to the slot corner position, and it's true that he flourished after moving inside following the acquisition of Aqib Talib. But he also outperformed his reputation on the outside, playing well against tough covers as the season progressed.
Never was this more evident than in the AFC Championship Game, where Arrington had to move to the outside following the early injury to Talib.
Arrington, who was matched up against the lightning-fast Torrey Smith on many plays, yielded just three catches for 49 yards on seven targets over 66 snaps. More impressively, Arrington showed that he is capable of playing press coverage against a true burner, demonstrating both re-routing and mirroring skills that far exceed his reputation.
Let's take a look at one play in particular.
Arrington is lined up at the top of the screen, showing press against Smith.
Though this screenshot is a little early, Arrington is going to stagger his feet (outside foot forward, inside foot back) before the snap to leverage Smith inside. That's by design. In a third and long situation, the Pats would rather the Smith catch a slant between the hashmarks (with the safeties back to make the tackle) than have a shot at a big gain along the sidelines.
As soon as the ball is snapped, Arrington engages with Smith. It's classic press—Smith isn't able to get anywhere close to a clean release off the line, so he can't use his straight-line speed to get separation.
Arrington is playing Smith as physically as Bill Polian's rules allow, riding him out past the line of scrimmage and rerouting him inside. Smith is running nowhere close to the 10-yard out drawn up for him, and it's all because of Arrington.
Smith has fought his way to the outside, but has no separation established. Arrington's physical coverage has destroyed Smith's advantage in speed, throwing off the timing route to the outside.
It's important to note that Arrington is doing this without safety help over the top. Football fans saw Smith dust none other than Champ Bailey in the divisional round, so for Arrington to bump Smith off the line and stay with him as he turns upfield is nothing short of impressive.
The pocket has collapsed on QB Joe Flacco, and Smith is nowhere close to open. Arrington has mirrored him perfectly on the out-route, pursuing Smith tightly across to the sideline. Flacco simply has to throw the ball away.
This is exactly the kind of tight, physical coverage Pats fans should want to see from their corners. It's why Arrington allowed a lower completion percentage this season than Aqib Talib, and a lower yards per snap than Devin McCourty.
Arrington didn't record an interception this season, one year after notching a league-leading seven. Still, he totalled 11 passes defended in 2012 (second on the Pats behind McCourty), including eight PDs in the last eight games of the regular season.
His improvement in that category largely came after his move to the slot position, which may have something to do with being able to keep the play in front of him. As mentioned above, he struggles to get his head around on balls, and thus he has to guess where and when the ball is coming in.
Even still, his 26 PDs over the last two seasons leads the Pats by a wide margin, and if New England can acquire enough depth to keep Arrington as a playmaker in the slot, all the better.
Run Defense/Special Teams
Coach Bill Belichick values DBs that can play the run (one reason why the trade for Aqib Talib made sense), and Arrington is the best run-stuffing CB the Pats have (assuming McCourty sticks at safety). He grades out as the 17th-best CB in the NFL against the run based on ProFootballFocus' metrics, receiving only one negative score all season (Week 11 vs. the Colts).
But that's not even the extent of Arrington's value. He's a core special teamer, where he's 17th in the NFL in total special teams tackles (13) and third on the Pats' coverage team behind specialists Matt Slater and Nate Ebner.
All this, and he's only 26—with room to grow and a demonstrated willingness to learn.
Although the market for CBs is inflated in a passing league, Arrington might still be had relatively cheaply. At 26, a two-year deal that keeps his cap hit manageable (he had an $825,000 base in 2012) should be doable for both sides.
As a fan? All I ask is that you look beyond Arrington's talk-radio reputation and appreciate him for what he is: a good, versatile, hard-working corner with room to grow.