Worst Cornerback Charting Stats 2012

by Rivers McCown

Yesterday we looked at the cornerbacks with the best charting statistics in our game charting project, so we'll balance that out today by talking about the worst.

As usual, the typical caveats about the game charting apply: This is imperfect data based on the game charting project, which means it comes off limited television camera angles, and it is charted by a group of volunteers plus a handful of FO staff members. Sometimes a cornerback will benefit because he happens to be in coverage when a quarterback throws a bad pass, even if he wasn't covering close. Sometimes a cornerback will benefit from a better pass rush, because it's easier to cover when you don't need to cover for six seconds. As we always say, these stats should not be seen as absolute statements on player value. They're just part of the story.

These tables rank all cornerbacks with at least 40 charted passes. As we do with the cornerback charting stats in the book and on the player pages, we've removed passes marked as Hail Mary, Hit in Motion, Tipped at Line, or Thrown Away. We've also removed wide receiver screens, which aren't really a good way to measure cornerback coverage because a cornerback in man coverage is going to (or at least, is supposed to) immediately get blocked out of the play by another wide receiver.

Because of this year's delay in posting the stats, we at least are able to provide you with our most accurate numbers. These stats have been analyzed to give half-credit on plays where we list two defenders in double coverage, or where we listed DEFENDER1 as "Hole in Zone" but also list a specific defender as responsible for that zone. We also have both actual numbers and the metrics adjusted for the quality of receivers each cornerback had to cover.

Pass interference is included, although no other defensive penalties are included. With defensive pass interference, the defender flagged is almost always the player who was in coverage on the intended receiver; with illegal contact or defensive holding, the flag often comes far away from where an actual pass may be thrown.

We'll start with the cornerbacks who allowed the most yards per pass according to our game charting.

While looking at this bounty of data, I thought you might enjoy a brief interlude from Andy Benoit, who writes about these guys from a scouting perspective for us. Here's his take on a cornerback who, for the convoluted and flimsy purpose of building suspense, I will call Player X:

"[Player X] is on the cusp of being a top-10 cornerback. He operates well in true man coverage, makes plays on the ball, and is a very effective tackler in space near the line of scrimmage. It’s vital that [Team Z] find someone to play across from him."

If you want to spoil the game, click here to see where that quote came from. If not, I'll try to make it a little more obvious in this one:

"(Team Z) recognized their futility at this position and dealt their 2013 second-round pick to (Team J) for corner (Player X). The supremely talented, mercurial, fourth-year pro immediately supplanted (Player G) in the starting lineup and gave (Team Z) a capable man-to-man defending playmaker. The second-rounder was a steep price, as it will likely be a high second-rounder, but (Player X) has shown the ability to be worth it."

If you seriously haven't figured it out yet, or have trained yourself so as not to spoil surprises like this, you lead a more saintly life than I.

Player X (the last blurb about him comes from here) is Vontae Davis, who is probably the most surprising entry on this list. I don't bring up these scouting blurbs to pick on Andy, I just found his reports on Davis to be a huge departure from what we are now looking at statistically. I didn't watch every Colts game with an emphasis on Davis or anything, but I do spend a lot of time with the AFC South because I root for the Texans. At no time did I thought Davis lived up to Andy's opinions of him. I can appreciate the physical talents, but I don't think he has shed the "mercurial" label yet.

While I happily made the case that I don't think the top of the cornerback tiers can tell us too much yesterday, I do believe that the outliers on the bottom jive with conventional wisdom a bit more. To me, the most practical applications we find with advanced statistics is not who is the best, but who is the worst. That goes double for regression-based systems like Playmaker Score and the Lewin Forecast. As long as the data is indeed looking at the "right" things (i.e.: not how going to a junior college is going to make Jason Pierre-Paul be bad at sacking a quarterback), it seems to me that a system is better measured by who it picks as bad rather than who it picks as good. Other than Davis, the only guy on this list that is a surprise is Aqib Talib, and he played to keep balls in front of him with such regularity that it's not hard to see why he made the list.

In unsurprising news, DeAngelo Hall made a list of bad cornerbacks on Football Outsiders. If you were around for Humble Leader's Sloan Analytics panel, you may remember Hall as "the most overrated player in the NFL." This year did nothing to change that reputation.

Our worst cornerback, Rashean Mathis, at least has a few pretty legitimate excuses. A) He was coming off an ACL injury in 2011 and B) he was 32. Mathis was benched by the end of the season despite that meaning that Aaron Ross would see increased playing time. If you aren't familiar with Aaron Ross' NFL work last season, watch this incredible segue I came up with to get to him...

Next, we'll look at the worst cornerbacks in Success Rate. Success Rate, to remind everyone, is the percentage of passes that don't manage to get at least 45 percent of needed yards on first down, 60 percent of needed yards on second down, or 100 percent of needed yards on third down.

Ross made comments alluding to the fact that this was a vacation year for him in Jacksonville. Well, he certainly played like it. He's emblematic of the weirdness that was Jacksonville's recent free-agent spending: Ross was never good when pushed into a starting role for the Giants, but for some reason the Jaguars brought him in to start anyway. The Jaguars started last season with Derek Cox, Ross, and Mathis looking like a respectable, if not amazing, collection of corners. They ended it with guys like Mike Harris, Kevin Rutland and William Middleton making starts.

Don't worry too much about Morris Claiborne's appearance here, Cowboys fans. Even the best cornerbacks tend to struggle early in their careers, and Claiborne was playing plenty of press-man. If you're going to worry about anything, worry about why they changed defensive coordinators after investing big money and draft value in Claiborne and Brandon Carr.

Finally, let's take a look at those who allowed the most YAC.

If you asked me which type of player would lead the league in YAC allowed, yeah, I'd probably have gone with someone like Leonard Johnson. Johnson, an undrafted rookie from Iowa State, was only on the field because the Bucs dealt Talib away and dealt with an injury to Eric Wright.

Complete numbers for all players, along with the great analysis and master wordplay you've come to expect from us, will be in Football Outsiders Almanac 2013 at some point in mid-July.