Best Cornerback Charting Stats 2011

Best Cornerback Charting Stats 2011
Best Cornerback Charting Stats 2011
Photo: USA Today Sports Images

by Aaron Schatz

So, it's time to start going through all the various numbers we have for 2011. I want to apologize for taking so long to do some of this. The game charting project ended up running a bit long this year trying to catch up with missed game. Other features haven't been updated yet because we had a bad run of interns taking forever to do projects or straight-out disappearing on us. That's one reason, for example, why the player pages have not yet been updated with 2011 data and 2009-2011 similarity scores. Hopefully we'll be able to make those updates soon. (I also was holding out until I finished with a new version of DVOA that normalized every season to 0% and looked at questions about the "red zone bonus," but it doesn't look like that will be ready for another few weeks.)

Anyway, the game charting has been complete for a few weeks, and now we've had a chance to do some cleaning on it where two charters disagree, and overall I'm ready to toss out some numbers. These are updated versions of the numbers I ran here in December. 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. I removed all safeties except for Antrel Rolle, who is often playing as a cornerback when the Giants are in nickel (which they are an awful lot of the time). As we do with the cornerback charting stats in the book and on the player pages, I've removed passes marked as Hail Mary, Hit in Motion, Tipped at Line, or Thrown Away. I'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. Right now I'm only looking at primary defenders, so this is not adjusted to account for double coverage, or plays where the charter marks a hole in zone but lists an appropriate zone defender in the second DEFENDER column. There are no opponent adjustments yet. However, pass interference is included. 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 fewest yards per pass according to our game charting.

Top 10 Cornerbacks in Yards/Pass, 2011
Player Team Charted
Yd/Pass Rk Success
Rk Avg. Pass
Cortland Finnegan TEN 56 4.3 1 64% 6 7.8 2.6 14
Brice McCain HOU 50 4.4 2 70% 1 9.9 3.4 44
Asante Samuel PHI 61 4.4 3 67% 3 14.7 2.0 2
Chris Culliver SF 50 4.9 4 54% 36 10.5 2.7 17
Ike Taylor PIT 98 5.1 5 63% 8 13.5 2.5 10
Alterraun Verner TEN 49 5.2 6 61% 12 10.0 2.3 6
Aqib Talib TB 45 5.3 7 62% 11 12.5 4.5 65
William Gay PIT 75 5.5 8 56% 29 10.4 2.7 19
Will Allen MIA 42 5.6 9 60% 18 9.9 3.3 36
Richard Sherman SEA 81 5.6 10 68% 2 14.1 2.5 8

Cortland Finnegan had an excellent year and demonstrates the kind of year-to-year variability we've found to be a problem with these cornerback charting stats. He was also near the top of the league in 2009, but in 2010 he ranked 65th in Success Rate and 76th in yards per pass. Which cornerback are the Rams getting next year? Perhaps we need to look at whether cornerback charting stats have more consistency if we look at them two or even three years at a time. The flipside to Finnegan's inconsistency would be Asante Samuel's consistency. Samuel ranked first in both yards per pass and Success Rate in 2010, then third in both for 2011. Yes, this is the guy the Eagles are trying to trade because they want to be able to move Dominique Rodgers-Cromartie outside and play more man coverage. Samuel is still really good and would be a huge addition to any team that plays primarily zone coverage.

In between Finnegan and Samuel, that's 2009 Houston sixth-round pick Brice McCain taking advantage of the Texans' newly vigorous pass rush to blanket opposing receivers. Culliver, Verner, and Allen also fall into the nickelback category. And we talked about rookie Richard Sherman's phenomenal year a bit when we did the midseason update

Notice someone missing? When I ran the midseason update on game charting for cornerbacks, Darrelle Revis ranked first in the league in both yards per pass and Success Rate. Now that we have stats for the entire season, he ranks 16th in both stats. Now, that's still nicely above average, and given the variability in cornerback stats I noted just above, the drop shouldn't be seen as incontrovertible evidence that Darrelle Revis is no longer the best cornerback in the National Football League. I would still take him ahead of everyone else (unless I was absolutely wedded to playing a zone scheme; then I would probably take Samuel).

Why did Revis fall so much in this final tally of cornerback charting stats? First of all, we were missing a lot of Jets charting when I ran that first batch of numbers in December, so Revis' numbers were based on a smaller sample size than those of other starting cornerbacks. The other reason for Revis' drop is that Revis himself apparently struggled a bit during the second half of the season. Check out his charting stats split into before and after the Jets' Week 8 bye:


Yd/Pass Success
Avg. Pass
Weeks 1-7 31 3.9 68% 16.5 1.7
Weeks 9-17 50 7.8 56% 11.3 3.8

This could be noise. It could be evidence that the knee injury that limited Revis in practice during the final two months of the season was a bigger deal than anyone realized. It could also be evidence that Revis has lost his place as the best cornerback in the league. Could be. I don't think it is.

Fortunately for the Jets, this falloff from Revis was offset by surprising improvement from Antonio Cromartie:


Yd/Pass Success
Avg. Pass
Weeks 1-7 36 7.4 50% 14.1 1.8
Weeks 9-17 38 6.2 71% 17.8 2.7

Next, we'll look at the top 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.

Top 10 Cornerbacks in Success Rate, 2011
Player Team Charted
Yd/Pass Rk Success
Rk Avg. Pass
Brice McCain HOU 50 4.4 2 70% 1 9.9 3.4 44
Richard Sherman SEA 81 5.6 10 68% 2 14.1 2.5 8
Asante Samuel PHI 61 4.4 3 67% 3 14.7 2.0 2
Richard Marshall ARI 50 7.1 35 66% 4 11.1 4.1 59
Chris Gamble CAR 61 6.2 15 66% 5 13.9 2.9 23
Cortland Finnegan TEN 56 4.3 1 64% 6 7.8 2.6 14
Dimitri Patterson CLE 53 6.1 13 64% 7 10.2 4.5 63
Ike Taylor PIT 98 5.1 5 63% 8 13.5 2.5 10
Carlos Rogers SF 99 6.5 19 63% 9 12.7 5.5 76
Brent Grimes ATL 48 6.1 14 63% 10 15.6 4.7 68

This table has some of the same names, and some surprising ones. Chris Gamble and Richard Marshall were both horrible in 2010, and both were a lot better in 2011 -- one with a new defensive coordinator, and the other with a new team.

This next table is more for conversation than for any kind of evidence of which players were or were not very good this year.

Top 10 Cornerbacks in YAC Allowed, 2011
Player Team Charted
Yd/Pass Rk Success
Rk Avg. Pass
Keenan Lewis PIT 47 6.5 18 45% 69 11.2 1.3 1
Asante Samuel PHI 61 4.4 3 67% 3 14.7 2.0 2
Jason McCourty TEN 98 6.8 31 57% 24 11.4 2.1 3
Kareem Jackson HOU 56 10.1 74 46% 63 16.4 2.1 4
Antonio Cromartie NYJ 74 6.8 28 61% 14 16.0 2.2 5
Alterraun Verner TEN 49 5.2 6 61% 12 10.0 2.3 6
A.J. Jefferson ARI 95 7.9 49 46% 66 13.8 2.3 7
Richard Sherman SEA 81 5.6 10 68% 2 14.1 2.5 8
Leon Hall CIN 45 8.2 55 51% 49 13.4 2.5 9
Ike Taylor PIT 98 5.1 5 63% 8 13.5 2.5 10

One more tidbit for today. I talked above about Asante Samuel's great year. What about the other Philadelphia cornerbacks? Well, it turns out we don't actually have the minimum 40 charted targets for any of the other Eagles cornerbacks. So I'll just present them all in one table so Eagles fans can have fun debating whether the team is making the right move by trying to deal Samuel. There's also a strong debate to be had about whether the Eagles were just using Nnamdi Asomugha wrong, or whether he's really not as good as we all thought.

Philadelpia Eagles Cornerbacks 2011


Yd/Pass Success
Avg. Pass
Asante Samuel 61 4.4 67% 14.7 2.0
Joselio Hanson 39 7.6 49% 10.6 3.3
Nnamdi Asomugha 36 9.0 56% 15.8 2.5
Dominique Rodgers-Cromartie 33 6.9 61% 13.6 5.8

Next week, I'll flip the script and run "10 worst" tables for cornerback charting stats.


78 comments, Last at 17 Apr 2012, 7:49am

1 Re: Best Cornerback Charting Stats 2011

Man, for a couple years I've wondered why Samuel isn't considered in the same breath as Revis and Asomugha. After watching them both play in 2011, I've got to say there's no comparison: Samuel is better in every phase and at no point did I see anything that Asomugha did better. Asomugha didn't seem notably more effective than DRC. I'd take Samuel over Revis even and not feel bad about it. Not saying he's better, but that he's the cream of the crop when it comes to #1 CB's...

(I am also remembering Eli's quotes this year about he won't even look Samuel's way because he's so unpredictable and tries to bait QB's into making throws he knows he can break up...)

11 Re: Best Cornerback Charting Stats 2011

One thing to note is that the past two years Samuel has been much better than his first two years with the Eagles:

I'm sure there is some lingering free agent who fell short of expectations dogging him.

13 Re: Best Cornerback Charting Stats 2011

Am I reading those charts wrong? His 2009 stats look awful good (like 9 interceptions and ranking #1 in stop rate and #4 in yard/play good), meaning he's been Top 5 for 3 years at least (and suffered none of the up and down WTF-ery of other top CB's...)

(Sure, his run support was bad in 2009... but so what?)

19 Re: Best Cornerback Charting Stats 2011

The perception of Samuels is that not only is he bad at run defense, he's indifferent at it. So sort of like how Jeter's artificially low range exaggerates his success rate, Samuels is only so-so at the run tackles he attempts -- and he doesn't attempt many.

Asomugha seemed totally lost in zone coverage early in the season last year, but much better in man. Samuels excels in zone. Philly ran a lot of zone. Hence Samuels doing better than Asomugha last year.

By the way, any chance Cromartie and Revis simply traded jerseys starting in week 9?

49 Re: Best Cornerback Charting Stats 2011

No, he's definitely bad at run defense by any conventional measure - he's tiny and has terrible technique (so he's just as likely to hurt himself as bring down a runner) and he's been known to give an "ole" on more than one occasion or drop pursuit when he really should have taken another few steps after the ball carrier.

14 Re: Best Cornerback Charting Stats 2011

And one final thing, his 2008 numbers are eerily similar to Asomugha and Revis. His 2009 & 2011 numbers easily outpace Asomugha. Essentially, with Revis' down year in 2011, Samuel has comparable numbers in 2008-2011 to Revis and better numbers decisively than Asomugha. So... the FO numbers prove my point.

48 Re: Best Cornerback Charting Stats 2011

Fair enough. But I think putting his 9 interception Pro-Bowl lock season into your argument for why "public perception" is low might work against that idea.

Anyhoo, he's definitely some one who the public resists - it's amazing how much the fans in Philly are indifferent to him. He seems like he's a "me first, get paid" kinda guy, only he's never a distraction and there's no real substance to that perception...

2 Re: Best Cornerback Charting Stats 2011

As a lifelong Iggle and NFL fan, I would say:

a) they used Nnamdi wrong, it was pretty clear,
b) Asante is still better than him, and everyone not named Revis Island.

It's fine to trade him...depending solely on what they get back of course. A stud LB? A pro-bowl Safety who wants more money for 1-2 more years? An interior run-stuffer and a high-draft choice? Etc.

9 Re: Best Cornerback Charting Stats 2011

I'm not sure there's any upgrade the Eagles' need that would be worth the downgrade of losing Samuel. Maybe a high pick, but I have no idea what he could bring. They don't need an LB anymore, a Pro-Bowl safety upgrading over Allen wouldn't be equal to the downgrade from Samuel to DRC (and perilous depth at CB it would bring).

of course, I'd be up for them dropping Jenkins and Babin because both DT and DE are problem spots (especially now with Parker gone and no one either proven or with upside behind the awful Babin), but the Eagles' front office clearly disagrees with me.

5 Re: Best Cornerback Charting Stats 2011

I actually think the most interesting story of the entire season was Asomugha. It of course gets no attention compared to His Holiness, but it's far more interesting to me.

I am, of course, an idiot, but I would not have put any other cornerback I've ever seen in the same category as Asomugha in Oakland (and I did see him a fair amount, being a Broncos fan). However, he clearly did not perform at that level last season. One one hand, the defense had much publicized schematic problems, particularly early in the year, that probably at least contributed to his issues. On the other hand, he is a 30-year-old converted safety, so he could just be in his decline.

6 Re: Best Cornerback Charting Stats 2011

Here's the thing I kept thinking while watching him this year: man, he looks like he has guys blanketed, but when the ball comes out, he never seems to put his body in exactly the right position to make a play on it. Him getting manhandled by Victor Cruz in two games was the clearest example of that - he looked like he had the coverage all sewn up... but then the ball would just zip by him or get snatched away. I wonder how much of his rep was built on the fact that no one ever threw his way because he LOOKED like the was no way to get a pass past him... He just doesn't have even halfway decent ballhawk skills - and maybe that's just bias from watching him play across from the league's #1 (or at worst #4) ballhawk...

4 Re: Best Cornerback Charting Stats 2011

Yeah, I think there's a good chance they have another ring by having not just a decent CB, but one of the best in the league on their roster. Him "dropping the interception" in the 2007 is such wildly over-stated non-sense - he was a great player who managed to come "this close" to winning the title right then and there with a great play...

7 Re: Best Cornerback Charting Stats 2011

I'll be shocked if Captain Munnerlyn doesn't have strong representation in the 10 worst lists. He seemed to be tied to the whipping post most of last season.

10 Re: Best Cornerback Charting Stats 2011

Also - hey, look, it's Eagles' fans favorite whipping boy Dimitri Patterson in the Top 10 on success rate (also 13th in YPA)! I always said he was unfairly maligned and a victim of instability at the safety position behind him in 2010. He genuinely was playing at a Pro Bowl level (stat-wise) that year in the first half of the season...

40 Re: Best Cornerback Charting Stats 2011

Someone can correct me if I'm wrong (and I'm sure they will!), but I'm pretty sure Patterson was the 3rd corner in Cleveland last year. My opinion when he was in Philly was that he was a first rate dime corner who was capable of playing the nickle (but didn't because of Hanson), but is overmatched (severely) as a starter.

12 Re: Best Cornerback Charting Stats 2011

Re. Revis's drop-off in the second half: the 5 yard decrease in average pass distance may shed some light. It seems that maybe opponents started throwing a lot more short hooks and slants, therby greatly increasing the percentage of completions and raising the YPA. I remember the Bills doing this with Stevie Johnson. Revis tends to give the receiver a decent amount of room underneath in non-short yardage situations.

18 Re: Best Cornerback Charting Stats 2011

It's amazing that a lot of Pats fans (not really one's here, but in general) seem to think that losing Samuel wasn't a big deal. I don't think the Pats could have afforded all of them, but they aren't perfect at knowing when to get rid of guys. Both Richard Seymour and Asante Samuel have performed well since leaving NE.

I've always thought of Asante as a great player, and his stats over the past three years in Philly have really been great. I think the one knock is that he isn't great at man coverage, but there is tremendous value in being the best off-man/zone corner in the NFL.

Am I wrong in thinking that he has a good HOF case. Great player for a long time. Has a run with a dynasty (he was there in '03-'04). Has a ton of the circumstantial things that HOF voters might like more than other people, like a ton of playoff INTs and four playoff pick-6's (as well as another that he returned to the 2).

16 Re: Best Cornerback Charting Stats 2011

Asante Samuel is still being talked as a "primarly zone corner" while he does play primarly man-coverage, just off most of the time, and with his eyes in the backfield a lot, and gathers consistently very good grades.

Chemical - I do value your opinion a lot, and while I think a debate exists around Babin (I personally think his "liability" against the run is perfectly acceptable when you have a very good offense that allows him to rush the passer a lot), the Eagles dropping Jenkins would be one of the dumbest move possible considering his impact on and off the field.

47 Re: Best Cornerback Charting Stats 2011

Well, my opinion on jenkins is actually, "he's about the worst possible dude to pair with Babin" in that they are both up the field rushers who play the pass first and can get corralled or manipulated away from the play with irritating frequency. In essence, Jenkins is a better version of Babin - he's less of a liability against the run - so if you put them next to each other, you're just begging for debacles like the Seahawks game. Jenkins is good (and unique disruptive due to his speed), but if you're going to play Babin for significant downs (and the Eagles are married to that idea), you need a steady, disciplined player beside him. What woudl make the most sense, of course, is losing Babin and getting a disciplined, run-oriented DE. Teams that commit to the ground game against a side of the field that goes Jenkins/Babin, Chaney, Samuel/Allen are going to have a ton of success both modest and highlight play-ish...

17 Re: Best Cornerback Charting Stats 2011

Call me a homer, but I'm amazed that Lardarius Webb (on the Ravens) wasn't anywhere in this article. Was he close?

22 Re: Best Cornerback Charting Stats 2011

Given that there are at least 100 cornerbacks who see regular time in the NFL is there any chance of seeing more than a top ten?

25 Re: Best Cornerback Charting Stats 2011

Man I can't wait until the Eagles trade Samuel for a 3rd round pick, which they'll then trade down from.


26 Re: Best Cornerback Charting Stats 2011

As a Steelers fan that's always like Ike and Gay, I'm glad to see it wasn't (just) my black-and-gold tinted glasses saying that they both played well. Sad to see Gay go, and that Ike's season is going to be remembered for 1 play, but that's the breaks.

"Cortland Finnegan had an excellent year and demonstrates the kind of year-to-year variability we've found to be a problem with these cornerback charting stats."
Maybe its not the stats. Maybe its the cornerbacks that are variable. That doesn't mean the stats are wrong, just that you can't put as much weight to them.

44 Re: Best Cornerback Charting Stats 2011

Looking at the charting Keenan Lewis should be ready to step in (ranked 18). Although I wouldn't be surprised to see more of Cortez Allen (who covered Gronkowski well last year) or Curtis Brown (was drafted 3rd last year).

27 Re: Best Cornerback Charting Stats 2011

The stats appear to perfectly confirm my impression of Kareem Jackson: he can't cover worth a damn, but at least he can tackle after giving up those 10 yards a pass. If this was 1972, maybe he'd be a better corner than Samuel . . .

45 Re: Best Cornerback Charting Stats 2011

Possibly, but 1. The Texans already have two good safeties and 2. I suspect that as a safety he'd just get lost and constantly be in the wrong place. Run support from CB and tackling the guy you're supposed to be covering don't require too much football intelligence. Playing safety (especially free safety) does.

60 Re: Best Cornerback Charting Stats 2011

The 49ers pretty much play the same defense regardless of who they're playing. They trust the front seven to shut down the run allowing the safeties to play over the top, all the corners get help. Johnson had a good game but they were able to take everyone else away.

33 Re: Best Cornerback Charting Stats 2011

little bit of a flawed stat. i would hope that asante would have better numbers covering #2 and #3 wideouts than nnamdi would have covering #1s. ( and the same for other corners on this list.) also how is the lack of pass rush on certain teams affecting corners. the jets have absolutely no pass rush so revis and cromartie are required to lock up with their wrs longer than lets say ike taylor or even the philly duo.

38 Re: Best Cornerback Charting Stats 2011

Yeah, I've always wondered if it would be possible to chart FO's CB stats against time spent in coverage. That way we could see which CBs are getting killed because they have to cover for a long time and which ones suck regardless of how long it takes the ball to get to them.

54 Re: Best Cornerback Charting Stats 2011

Yes. FO measures quick sacks and long sacks, which is very useful in telling us which QBs hold onto the ball too long and which have bad o-lines. The same principlal should apply to CBs who have to spend longer time in coverage.

Also there has to be consideration given to how many other defensive resources are committed to helping a given corner. Cromartie I'm sure gets a lot more coverage help than Revis island does. Not sure how you would measure that though.

51 Re: Best Cornerback Charting Stats 2011

Philly lines up right and left, yes - and this also depends on what you mean by #1 and #2. Samuel normally lined up across from Hakeem Nicks and Asomugha from Victor Cruz. Early in the year, most folks would have said Samuel was covering the #1 and Asomugha the #2 (or even #3) receiver. Not sure how much game-charting accounts (or could ever even speculate about) the #1, #2, #3 designations of a situation like that. Look at the Cowboys as well - how are we going with wideout rating there. Samuel covered Austin and Bryant in equal measure if I'm recalling things correctly and Asomugha ended up in the slot a lot in those games... (plus, who were the 1, 2, 3 in Washington? Aren't all of them #3's?)

36 Re: Best Cornerback Charting Stats 2011

It would be interesting to plot scatter graphs of the different variables to see if three are correlations between some of them and to see if certain players / systems group themselves.

Is a spreadsheet available of the first table for all corners?

42 Re: Best Cornerback Charting Stats 2011

I wonder how much of the desire to trade Asante is based on his performance on the field as opposed to him being a headache off it?

46 Re: Best Cornerback Charting Stats 2011

I think the majority of the reason for trading Asante is the fact that he's 31, and DRC is 26 (and Samuel costs $8.5M more than DRC). Still, though, since Asomugha's the same age as Samuel and costs more, I can't really say there's great logic there.

If it were me I'd just freaking find a way to keep all of them.

55 Re: Best Cornerback Charting Stats 2011

There's also the argument that the Eagles were not getting the most out of their 3 good CBs. I remember reading somewhere (I think here but I'm not sure), that teams played a lot fewer 3+ WR sets vs. PHI than against other opponents last year. Teams new they had 3 good corners so obviously they sent out formations that prevented PHI from fielding its best team. ISTR that 2 TE sets were hurting them.

Fact is that 3+ Pro Bowl level CBs is probably a roster inefficiency, especially is you are paying them all like PHI is paying their guys. Of course if you trade one and then one of the other 2 goes on IR you will become history's rgeatest monster.

56 Re: Best Cornerback Charting Stats 2011

This effect was probably further increased since the Eagle's d-line was not good against the run, and the linebackers in general were just awful.

Few teams might have 3rd receivers who can beat DRC, but they have plenty of linemen who can push Babin out of the way, and plenty of running backs who can run around, through, and over the linebackers.

If I were the Eagles I'd think long and hard about trying to trade one of their corners and Babin together for a superior end.

62 Re: Best Cornerback Charting Stats 2011

Not sure about not getting the most out of 3 good corners, but maybe not getting the right kind of guys for their defensive scheme. Nnamdhi and DRC are pure man corners and you might say Nnamdhi is a press-man corner, while Samuels is a zone corner. Already, the defensive coordinator is going to have problems fitting them into the defense.

On top of that Nnamdhi only plays on the (defensive) right side, while Samuels only plays on the (defensive) left side. When you switch their alignment and assignment, they're not as good in their new role, not as comfortable, and it showed. The funny thing was, despite Nnamdhi being a press-man corner on the right, the Eagles shifted him to the slot where he struggled. I think Greg Cosell and Mike Mayock covered how Nnamdhi struggled in his new role.

Though, it does make sense if you have two good man corners and one zone corner to trade the zone corner and switch to a man-based scheme.

59 Re: Best Cornerback Charting Stats 2011

I'm a Giants fan, but I have to say Darelle Revis dominated the Giants when the teams played on Christmas Eve. He gets away with a lot of stuff that should be penalties, but he swallowed Nicks up and Cruz did nothing on the few plays he covered him.

63 Re: Best Cornerback Charting Stats 2011

I would love to see the Jets/Revis/Cro with a decent pass rush. These guys have to play with such a terrible pass rush, and do such a great job.

64 Re: Best Cornerback Charting Stats 2011

The perception is that Revis is much better than Cromartie,
however, statistically their numbers are usually pretty similar.

65 Re: Best Cornerback Charting Stats 2011

Aside from the obvious concern that it's hard to compare corners who have different assignments—obviously if Asomugha has the best receiver every play his numbers will be worse—these number don't seem to take into account the fact that having fewer targets is a sign that your coverage is good. There's a selection effect—focusing on targets already removes the corners most successful plays from the sample. More interesting than success rate might be the number of unsuccessful plays each corner has. That won't tell us if a corner is really good or just a back up who doesn't play very much. But you also could look at the number of snaps each player played and compare to the other corners on the team. In the Eagles case, it looks like Samuel was getting targeted a lot—maybe he was baiting the QB. Looking just at the Eagles (if I understand these above numbers right) here are the number of unsuccessful plays each had:

Rodgers-Cromartie 13
Asomugha 16
Hanson 18
Samuel 20

That doesn't make Samuel look like the best cornerback. Of course all these players are just separated by a few plays. But then consider that Asomugha was in on the most snaps (according to data I found on Pro Football Focus Asomugha played 890 snaps, Samuel 769 snaps, and Rodgers-Cromartie 452 snaps). When I run those numbers here is the percentage of snaps on which each player failed to stop his man:

Asomugha 1.8%
Samuel 2.6%
Rodgers-Cromartie 2.8%

And wasn't Asomugha usually on the other team's top receiver? I think I would on the basis of these number I would still take Asomugha over the other guys.

66 Re: Best Cornerback Charting Stats 2011

PS I have now wasted way too much time trying to find complete snap counts for CBs in 2011. But I was able to find counts for a lot of the corners listed here. Nnamdi Asomugha actually gave up the fewest plays (had the fewest "unsuccessful plays") per snap of any players I could get data for. Cortland Finnegan was a very close second with 1.8% unsuccessful plays, followed by Richard Marshall with 2.0%. That sounds intuitively to me like a pretty good list of the best corners. Frustratingly, I couldn't find a snap count for Darrelle Revis (I would also really like to see the stats for Lardarius Webb and Brandon Carr).

For comparison, Brice McCain actually had an unsuccessful play on 3.8% of the snaps he played (and that was probably covering inferior receivers). I also looked at the CBs from the worst CBs article. The worst that I could find data for was E.J. Biggers, who had 51 unsuccessful plays. That meant he blew it on fully 8.7% of the snaps he played.

67 Re: Best Cornerback Charting Stats 2011

You've hit on an important question. The problem is getting accurate participation data; without all-22 footage, guys are lost outside the TV picture. If we knew which DBs were on the field for each pass play, then it would be possible to come up with both non-target and unsuccessful play percentages that would indeed be illuminating.

68 Re: Best Cornerback Charting Stats 2011

There are a couple problems here. You are relying on PFF being accurate with participation data (they aren't), and just because a corner isn't thrown at doesn't mean he did his job. It could mean the QB was sacked before he could even look down field, it could mean another corner simply did his job even worse, he could be covering a secondary or tertiary read, or he could be covering a clearing route, he could have more safety help over the top or more linebacker help underneath.

Also, the Eagle's fans on this site said Asomugha and Samuel played a specific side, they didn't match up to specific receivers.

69 Re: Best Cornerback Charting Stats 2011

I'm sure PFF isn't accurate, although I figure it's at least in the ballpark. I guess not having the all-22 is why no one has this data online. Even the snap count it were accurate, it would be a crude measure. It doesn't tell you how many times the QB was sacked or how many of those snaps were running downs. Presumably the third and fourth corners are in more often on passing downs. It would probably be better if we knew the number of snaps each CB was in where a CB was targeted in man coverage.

But we can still at least roughy compare Asomugha and Samuel. Even if PFF's numbers were wrong—PFF says Asomugha was in on 121 more plays than Samuel—they were both starting corners. According to these numbers Samuel yielded for more plays than Asomugha—25% more. Now if QBs had a greater success rate going at Asomugha may be they should have picked on him more often. But it does seem a reasonable assumption that the starting CB who was beaten more often was probably the worse corner.

71 Re: Best Cornerback Charting Stats 2011

I agree - these numbers seem VERY iffy as raw data. Also, you're not taking into account injury time - both Samuel and Asomugha missed time due to injury, which should matter. Normalized for injury, I can't imagine a way Samuel and Asomugha don't end up with more less the same # of snaps played - there's just no scenario in which Asomugha was on the field and Samuel was not. I even looked at randomly at a handful of their goal-line formations and Samuel was still on the field.

72 Re: Best Cornerback Charting Stats 2011

I'm not sure what you mean by normalized for injury. I don't trust the PFF numbers, but I think Asomugha did have more snaps because Samuel had to sit a game in December—can any Eagles fan confirm this? I think you're probably right that he was in every play when he was healthy. But it doesn't matter whether Samuel had fewer snaps because he was injured or because he was benched. If the FO numbers are correct, that means Samuel gave up MORE plays in FEWER snaps.

76 Re: Best Cornerback Charting Stats 2011

PFF's snap count data aren't perfect, but when I've compared them to other sources they've been very close. For instance, the Chicago Tribune had an article listing Bears' 2011 snap counts using "NFL-generated playing time statistics the Tribune acquired," which I assume is an independent source of player participation data. They counted fewer total snaps than PFF (which I believe is because PFF includes plays canceled by penalty in their total and the Tribune's source does not), so the totals not directly comparable, but if we compare what percent of the team's snaps each player played then they're very close.

On offense, the largest discrepancy was 1.02% of the team's snaps, for Dane Sanzenbacher - the Tribune had him on the field for 37.64% of the Bears' snaps (379/1007) and PFF had him on the field for 38.66% of Bears snaps (404/1045). That could be because PFF is off by a bit, or the Tribune source is off by a bit, or he just happened to be on the field for a lot of plays which were canceled by a penalty. On defense, the largest discrepancy is 0.70% of the team's snaps, for Major Wright: 53.75% of snaps according to the Tribune (581/1081) vs. 53.05% of snaps according to PFF (592/1116). (PFF also has snaps for 3 players who don't appear on the Tribune list, Chris Harris, Mario Addison, and Nick Reed - I believe that those guys all did play but were off the roster by the end of the season, so that's probably why the Tribune skipped them.)

70 Re: Best Cornerback Charting Stats 2011

It occurs to me that we can also extrapolate from this data to get the total number of yards each CB yielded in man coverage. Presumably FO doesn't list that because they thought rate stats would be more useful. But it is still interesting. Looking at the Eagles again we see that Asomugha actually gave up the most yards:

Rodgers-Cromartie 228
Samuel 268
Hanson 296
Asomugha 324

These are all pretty low numbers. The same math tells us that Devin McCourty managed to yield 996 over the course of the season by himself. Of course as Jerry points out without the all-22 it is hard to know who was on the field the most. Hanson was presumably on the field a lot less. Tuluse is probably right to say the PFF snap number are somewhat off, but they suggest that Asomugha was on for quite a few more snaps than Samuel. For fun I took the number of yards each corner surrendered per snap they were on the field. Then to get rid of the decimal I multiplied by 1000, essentially normalizing to for a full season of play for a starting CB. When you do that, these are the amount of yards each Eagles corner would have surrender if over an uninterrupted full season of starting (I don't have snap numbers for Hanson):

Samuel 349
Asomugha 364
Rodgers-Cromartie 504

Samuel beat Asomugha by this measure, although it's close. For various reasons—some teams have a better pass rush, play more zone, etc.—you can't necessarily compare these numbers across teams. But it's interesting that Samuel and Asomugha's normalized numbers are the best of any CB I could measure except one: Cortland Finnegan would have surrendered just 214 over the same length season of play. That blew away the rest of the field. I don't have the snap numbers for Revis, but there's no way he comes close. For comparison sake, E.J. Biggers once again would have done the worst. Over a normalized season he would have allowed a truly awesome 1,505 yards.

73 Re: Best Cornerback Charting Stats 2011

If you're a PFF subscriber, they have data on yards allowed per coverage snap under their "signature stats" tab. Out of the 111 players who played at least 25% of their team's coverage snaps (about 175 snaps), here's how the Eagles corners ranked:

3. Samuel 0.65 yards/play
6. Asomugha 0.70 yards/play
25. Hanson 1.01 yards/play
37. Rodgers-Cromartie 1.12 yards/play

Elite numbers for Samuel and Asomugha, and good numbers from DRC and Joselio Hanson.

They also have a separate tab that shows coverage performance in the slot. Out of 44 qualifying cornerbacks, the Eagles corners ranked:

2. Asomugha 0.75 yards/play
22. Hanson 1.22 yards/play
44. Rodgers-Cromartie 2.65 yards/play

Nnamdi was nearly the best, DRC was the worst, and Hanson was the most average.

74 Re: Best Cornerback Charting Stats 2011

Thanks, Dan. That's interesting. One thing that strikes me is that they tracked just 175 coverage snaps. That's just 11 per game. Opponents threw 520 passes against the Eagles. I suppose there were a lot of passes in the flat to RBs etc. But that's still surprising to me. Do the Eagles run that much zone?

75 Re: Best Cornerback Charting Stats 2011

I meant that it's their rankings out of the 111 cornerbacks who played at least (roughly) 175 snaps in coverage. 175 is just the minimum to qualify (actually it's more like 173). The Eagles corners ranged from 271 snaps in coverage (Hanson) up to 540 (Asomugha). (I assume they're counting some plays with sacks or scrambles to get over 520 pass plays.)

77 Re: Best Cornerback Charting Stats 2011

75 comments, and nobody's talking about the rookie for the Seahawks that schooled all but one person on that list, and in only TEN GAMES STARTED, no less? Richard Sherman might be the Peyton Manning of CBs in a few years if his trend continues.

78 Re: Best Cornerback Charting Stats 2011

Ten games started is a really, really small sample size, and cornerback charting stats often fluctuate wildly from year to year. Sherman obviously had a terrific rookie season, but it's far too early to conclude he'll actually be a good player over his career. Fred Bennett posted similarly impressive numbers as a rookie back in 2007, never reproduced that level of performance, and was out of the league by the middle of 2010, to give one example I'm painfully familiar with. Maybe Sherman will be great, but I wouldn't get too excited just yet.

Save 10%
& Support Aaron
Support Football Outsiders' independent media and . Use promo code SCHATZ to save 10% on any FO+ membership and give half the cost of your membership to tip Aaron.