Writers of Pro Football Prospectus 2008

07 Jun 2013

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.

Bottom 10 Cornerbacks in Yards/Pass, 2012
Defender Team Passes Tgt% Rk Yd/Pass Rk Suc% Rk PYD YAC Rk Adj Yds Rk Adj Suc Rk Rec
Rashean Mathis JAC 45 14% 73 10.7 87 42% 81 13.8 3.8 63 11.2 87 38% 85 25
Nnamdi Asomugha PHI 63 16% 51 10.4 86 46% 70 13.7 5.0 78 9.7 80 47% 65 37
Aqib Talib 2TM 62 21% 21 10.2 85 44% 74 14.1 5.3 81 9.5 78 46% 71 35
A.J. Jefferson MIN 48 11% 85 10.1 84 32% 87 13.1 2.7 28 10.0 86 33% 87 31
DeAngelo Hall WAS 92 18% 40 10.0 83 44% 77 11.9 4.8 75 9.7 81 46% 70 56
Jacob Lacey DET 35 12% 78 9.8 82 44% 76 9.5 6.3 84 9.8 84 46% 73 20
Corey Webster NYG 91 21% 13 9.7 81 47% 68 15.3 4.6 73 9.1 73 47% 68 50
Vontae Davis IND 54 19% 30 9.7 80 43% 79 14.5 2.5 14 9.9 85 41% 82 33
Patrick Robinson NO 100 21% 16 9.6 79 52% 45 15.2 6.8 85 8.9 72 53% 36 47
Buster Skrine CLE 84 17% 49 9.3 78 41% 83 12.8 3.5 54 9.1 75 42% 81 54

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.

Bottom 10 Cornerbacks in Success Rate, 2012
Defender Team Passes Tgt% Rk Yd/Pass Rk Suc% Rk PYD YAC Rk Adj Yds Rk Adj Suc Rk Rec
A.J. Jefferson MIN 48 11% 85 10.1 84 32% 87 13.1 2.7 28 10.0 86 33% 87 31
Aaron Ross JAC 49 13% 77 9.3 76 36% 86 11.3 4.0 70 9.7 82 33% 86 31
Antoine Cason SD 97 22% 7 7.4 41 40% 85 11.4 2.6 17 7.3 35 40% 84 60
Morris Claiborne DAL 59 16% 53 8.4 65 41% 84 13.4 3.1 43 7.9 54 41% 83 37
Buster Skrine CLE 84 17% 49 9.3 78 41% 83 12.8 3.5 54 9.1 75 42% 81 54
Josh Norman CAR 79 18% 42 8.9 71 41% 82 12.0 1.9 3 8.3 69 42% 80 50
Rashean Mathis JAC 45 14% 73 10.7 87 42% 81 13.8 3.8 63 11.2 87 38% 85 25
Cary Williams BAL 93 21% 15 8.2 62 42% 80 13.5 1.8 2 8.0 58 44% 79 56
Vontae Davis IND 54 19% 30 9.7 80 43% 79 14.5 2.5 14 9.9 85 41% 82 33
Joselio Hanson OAK 46 12% 80 9.0 74 43% 78 10.1 2.1 7 9.2 77 45% 75 35

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.

Bottom 10 Cornerbacks in YAC, 2012
Defender Team Passes Tgt% Rk Yd/Pass Rk Suc% Rk PYD YAC Rk Adj Yds Rk Adj Suc Rk Rec
Leonard Johnson TB 52 11% 84 8.4 64 59% 16 12.7 7.3 87 8.2 65 58% 16 27
Josh Wilson WAS 87 17% 48 8.8 70 56% 21 12.2 7.0 86 8.5 71 57% 17 41
Patrick Robinson NO 100 21% 16 9.6 79 52% 45 15.2 6.8 85 8.9 72 53% 36 47
Jacob Lacey DET 35 12% 78 9.8 82 44% 76 9.5 6.3 84 9.8 84 46% 73 20
Brice McCain HOU 49 14% 74 8.9 72 52% 46 9.6 6.2 83 9.6 79 51% 48 28
Alterraun Verner TEN 71 16% 56 7.5 43 54% 36 10.7 6.0 82 7.7 49 53% 38 40
Aqib Talib 2TM 62 21% 21 10.2 85 44% 74 14.1 5.3 81 9.5 78 46% 71 35
Sam Shields GB 45 15% 60 8.9 73 60% 12 15.9 5.3 80 9.2 76 57% 18 17
Darius Butler IND 41 13% 76 6.3 18 55% 28 11.7 5.0 79 6.8 26 54% 29 20
Nnamdi Asomugha PHI 63 16% 51 10.4 86 46% 70 13.7 5.0 78 9.7 80 47% 65 37

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.

Posted by: Rivers McCown on 07 Jun 2013

44 comments, Last at 05 Jul 2013, 1:31am by Cheap Nike Free Run UK

Comments

1
by fb29 :: Fri, 06/07/2013 - 12:35pm

(announcer voice): Rivers has grabbed hold of Andy's cornerback scouting ability and ohhhhhh BODY SLAM!

2
by justanothersteve :: Fri, 06/07/2013 - 12:44pm

Interesting that Johnson, Josh Wilson, and Shields are in the bottom ten for YAC and are 16, 17, and 18 in Success Rate. I'm guessing that all three were generally successful, but when they were beaten they were badly beaten.

6
by Jonrd :: Fri, 06/07/2013 - 1:07pm

Confirms what I thought I was seeing while watching the Bucs - Leonard Johnson looked like a capable corner most of the time, but he missed that tackle on Danario Alexander for the 80 yarder plus allowed 80 and 40+ yard passes to Julio. Two plays like that will cost you when you're talking about 52 passes total. I still think he can be an adequate starter in the league, and a nickel back at the least. Just hope he beats out Eric Wright for that spot this year.

3
by Shake (not verified) :: Fri, 06/07/2013 - 12:50pm

At the start of the season Vontae Davis looked like a guy that had shown up been handed a playbook and thrown out onto the field as a starter... for good reason, he started 3 games for Indy before he'd been with the team for a month. While he could still be shaky at times later in the year he looked much much better.

5
by Bobman :: Fri, 06/07/2013 - 1:05pm

Looking at the college players available and the Colts draft picks, one could surmise that the staff thinks they are at least adequately set and not featuring two of the worst CBs in the league.

7
by jedmarshall :: Fri, 06/07/2013 - 1:13pm

He was also hurt early in the year. I thought he played significantly better in the latter part of the year. I don't think he's great, but he's a more than capable starting corner and I'm anxious to see how he does next year with a familiarity with the system and a competent CB (i.e. not Cassius Vaughan) on the other side.

15
by Aaron Schatz :: Fri, 06/07/2013 - 4:36pm

That comment inspired me to look, and boy, are you correct. Obviously, five-game strings are small sample sizes, but...

Weeks 1-8: 19 passes, 10.9 adjusted yards per pass, 25% adjusted success rate
Weeks 13-17: 36 passes, 9.2 adjusted yards per pass, 53% adjusted success rate

4
by Bobman :: Fri, 06/07/2013 - 1:03pm

I wonder how this corresponds to the "Most Ineffective Pass Rush By Team" charting project....

8
by CaffeineMan :: Fri, 06/07/2013 - 2:14pm

Any chance of getting the splits for both of Talib's teams?

9
by Parmenides :: Fri, 06/07/2013 - 2:33pm

Josh Norman, the receiver will catch the ball, but then be immediately tackled.

10
by theslothook :: Fri, 06/07/2013 - 2:39pm

Did Cassius Vaughn bribe Rivers to leave him off this list? I am simply baffled at how he didn't end up at or near the bottom of every major category.

13
by Vincent Verhei :: Fri, 06/07/2013 - 4:01pm

Vaughn was in a virtual tie with Joselio Hanson for the last spot on the Worst Success Rate list. One more catch would have made the difference.

Vaughn ranked in the 50s in yards allowed per pass, which is below average but not catastrophic or anything.

11
by Revenge of the NURBS (not verified) :: Fri, 06/07/2013 - 2:55pm

Random thoughts:
Interesting that Talib was playing to keep the ball in front of him, but then still was one of the worst at allowing YAC. Keeping the ball in front of you doesn't do much good if you don't make the tackle.

Nnamdi Asomugha's fall from "elite" status is apparently so well established in these parts that his presence on this list doesn't even warrant a mention.

As a Colts fan, not surprised to see Vontae Davis here, although I do agree with those who have said that he improved later in the year. Gotta be partly a function of being traded right before the season and thrown out there without knowing the playbook. Also not surprised to see Jacob Lacey on here.

16
by Sifter :: Fri, 06/07/2013 - 6:03pm

You posted exactly what struck me - Talib keeping guys in front of him and conceding a lot of YAC doesn't make sense. Was it down to 1 or 2 plays? Or is Talib a bit overrated? I know Pats fans crowed about the difference he made to their secondary, mainly by pushing every other DB down a peg...and while that's nice, if your #1 CB isn't as good as everyone thinks then the gains may not be as big as everyone thought.

17
by Anon E. Mouse (not verified) :: Fri, 06/07/2013 - 6:39pm

This isn't exactly rocket science analysis but passing yards per game declined from an average of 285.33 to 253.42 once Talib came to the Pats. But then they also gave up more rushing yards (96.7 before, 108.4 after). Not really a big difference in yards allowed per game, without any adjustments for opposing talent.

24
by JT (not verified) :: Sun, 06/09/2013 - 10:07am

I would be very curious to see a breakdown of Aqib Talib's stats and rankings first strictly with the Bucs, and then solely with the Patriots. From what I saw he did not play well at all last year with Tampa Bay, but then played much better with New England.

12
by Quixzlizx (not verified) :: Fri, 06/07/2013 - 3:56pm

You have Aaron Ross as a NYG in the table. I know he'll probably be there as a Giant next year, but there's no sense in jumping the gun.

14
by Aaron Schatz :: Fri, 06/07/2013 - 4:29pm

Will fix.

18
by Nate Dunlevy (not verified) :: Sat, 06/08/2013 - 9:59am

I have never seen a bigger gap between actual performance and fan perception of that performance than with Vontae Davis.

If you ask Colts fans, they'll tell you he was awesome.

Fans are so eager to justify the high price for acquiring him, that they simply forgot how awful he was for most of the year.

22
by theslothook :: Sat, 06/08/2013 - 6:18pm

Would you be surprised if he had a good turn around season this year? I also think improved defensive quality in general will make him play better. Or maybe this is all wishful thinking on my part.

32
by FrontRunningPhinsFan :: Mon, 06/10/2013 - 11:59am

I think the scouting report part of the article about him is pretty spot on. The chance he has a good year and improves is mostly based on his mecurial personality. When Brandon Marshall was with the Dolphins, there was a big stink during practice early one season (maybe even training camp - I'm too lazy to look it up) because Marshall shoved a ball in Vontae's face and was screaming at him on the field. This initially quickly snowballed into "Here we go with Marshall again" then it turned out he was screaming at him for being hung over and telling him he was being a bad teammate and needed to get his act together. So basically, he deserved it.

He's got a lot of physical talent but the question is, does he have the drive? He never really seemed to in Miami which is why they were fine getting rid of him. In my opinion, his year (and career) are wholly dependent on him devoting himself to being great.

Fire Jeff Ireland.

19
by DEW (not verified) :: Sat, 06/08/2013 - 11:47am

There's a lot of correlation between yards/pass and YAC, it seems, but the names that stick out are the ones that appear both on the Y/P and Success Rate tables: Mathis, Jefferson, Davis, and Skrine. Guys that allow the opposition to complete passes often and deeply. The guys that the opposing QB looks for on 3rd-and-17.

33
by FrontRunningPhinsFan :: Mon, 06/10/2013 - 12:00pm

Deleted as I accidentally replied to wrong comment.

But still - Fire Jeff Ireland.

36
by Noah of Arkadia :: Mon, 06/10/2013 - 2:46pm

Would you consider putting your sig on probation until the year plays out? Miami had a solid offseason, I thought.

------
As Mr. Sloan always says, there is no "I" in team, but there is an "I" in pie. And there's an "i" in meat pie. Meat is the anagram of team... I don't know what he's talking about

37
by FrontRunningPhinsFan :: Tue, 06/11/2013 - 7:47am

Ok fine. I think they had a good one too, but more in spite of him than because of him. I think the players like the coaching staff in place and they threw boatloads of money at free agents.

As far as the draft goes there's obviously no way to know that yet.

Of course winning the offseason is not the same as winning the regular season, but I'm more hopeful this year than last year, and last year I was more hopeful than I had been for a long time.

38
by Noah of Arkadia :: Tue, 06/11/2013 - 9:52am

Pretty much sums up how I feel, except for the "in spite of" bit. I think what Ireland did this year was include the coaches in his decisions more. Which goes back to the coaches again, but the fact is Ireland didn't have to do that. He could've been a dick and signed whoever he wanted to sign.

------
As Mr. Sloan always says, there is no "I" in team, but there is an "I" in pie. And there's an "i" in meat pie. Meat is the anagram of team... I don't know what he's talking about

39
by theslothook :: Tue, 06/11/2013 - 3:31pm

Whatever happens this year will have less to do with Ireland's decisions and more to do with Tannehill's progression. If he has a sophomore slump, then it probably won't matter what free agents the dolphins had brought in.

40
by Noah of Arkadia :: Wed, 06/12/2013 - 12:10pm

Yup, everything depends on Tanny continuing to grow.

------
As Mr. Sloan always says, there is no "I" in team, but there is an "I" in pie. And there's an "i" in meat pie. Meat is the anagram of team... I don't know what he's talking about

20
by HailToST21 (not verified) :: Sat, 06/08/2013 - 12:08pm

I'm not sure that D'Angelo Hall can rightly be called "The Most Overrated Cornerback" anymore, due to the fact that he took a massive pay cut in DC this offseason. It seems like he's getting paid closer to his true value now. Last year, I would have called Asomugha the most overrated. This year, let's find out! I think Aqib Talib is the frontrunner at the moment.

29
by apk3000 :: Mon, 06/10/2013 - 8:03am

I would say that Hall couldn't even be called overrated for the past couple of years. The only people who don't think he sucks are DeAngelo Hall and Dan Snyder.

21
by Jon Goldman (not verified) :: Sat, 06/08/2013 - 5:34pm

Happy to see that Buster Skrine is, in fact, as terrible as everyone thought/thinks he was/is.

42
by herewegobrowniesherewego (not verified) :: Thu, 06/13/2013 - 1:20pm

It was as clear to me as "Pope defecates in forested area," to paraphrase a Big Lebowski line.

There'll be a lot of trouble if he still starts ahead of McFadden, which looks possible after the first workouts. Although I think Horton can get enough out of Haden and Ward to make up for the rest of the D-backfield.

23
by slipknottin :: Sun, 06/09/2013 - 7:31am

Aaron Ross was actually a very good starter for the giants, but only in the postseason

25
by Anonymously (not verified) :: Sun, 06/09/2013 - 9:57pm

I dunno. Seeing Nnamdi on this list after seeing him on the best corners list a few years ago should make everyone question the value of this exercise.

Moreover, having Nnamdi go from shutting off an entire quarter of the field in OAK to being a flop in Philly should make everyone question everything they think they know about assessing individual talent in this, the most team oriented of all our professional sports.

26
by Karma Coma :: Sun, 06/09/2013 - 11:43pm

Is it really "the most team oriented?" More than pair skating, for example, or beach volleyball?

27
by RickD :: Mon, 06/10/2013 - 12:33am

"Seeing Nnamdi on this list after seeing him on the best corners list a few years ago should make everyone question the value of this exercise."

I don't understand.

"Moreover, having Nnamdi go from shutting off an entire quarter of the field in OAK to being a flop in Philly should make everyone question everything they think they know about assessing individual talent..."

I think the consensus opinion is that Asomugha was a much better CB in Oakland than he was in Philly, and the stats support that conclusion.

Rather than assert the futility of the entire exercise, while blaming Asomugha's precipitous decline in performance level as something due entirely to the team he was playing on (as if the Raiders were some kind of defensive juggernaught), maybe we should accept the simpler explanation: he used to be great, but he isn't any longer. And these statistics demonstrate objectively and unambiguously that his level of performance dropped a lot.

That's what statistics are for: to tell you what happened. You can get into a discussion about why things happened the way they did, and certainly statistics should be included in that discussion. But simply rejecting the statistic because it doesn't provide a guarantee of future success (even when it is aligning extremely well with casual opinions of a given player's performance level) - this is, well, something I don't understand. You're really not debunking the value of the statistic here. It's doing exactly what it's supposed to be doing.

28
by theslothook :: Mon, 06/10/2013 - 3:09am

Seconded...I think scheme being named the primary culprit for why nnamdi going from shutdown to trash is pretty much a stretch no matter which way you look at it. Despite however you measure db performance, giving up huge yards to receivers as a corner is pretty much the definition of not doing your job well.

That said, schemes and talent around you do indeed impact your nominal performance. Unless nnadmi absolutely tears it up with the 49ers, its more than likely he will be no better in sf than he was in philly.

34
by Karl Cuba :: Mon, 06/10/2013 - 12:02pm

Thirded, if that's a thing. The stats actually showed that he began to decline quite precipitously in his final year in Oakland.

As a 49er fan I hope he can regain his old form but I'm not counting on it and as he has no guaranteed money, neither are the niners.

30
by ChicagoRaider :: Mon, 06/10/2013 - 8:23am

I do not see how Oakland failed to populate this list more. Take it from me, these stats do not capture the awfulness of the Oakland secondary last season.

31
by CBPodge :: Mon, 06/10/2013 - 11:10am

Please can we have the annual stats for Hole In Zone? Has he improved on last year, or regressed? How many NFL players did he outperform?

35
by Ryan D. :: Mon, 06/10/2013 - 1:09pm

+1

41
by mrh :: Wed, 06/12/2013 - 12:51pm

Maybe Sanford Routt didn't make the 40 play cutoff. Otherwise I can't see how he didn't make the list.

43
by Robert Ferringo (not verified) :: Tue, 06/25/2013 - 8:28pm

How did Janoris Jenkins not make any of these lists?

I know he fluked his way to some touchdowns. But he was not an NFL-caliber corner last year. His two-week stretch against the Patriots and Packers alone should've landed him in the Top 10. He was awful for most of last year.

44
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