Signature Stats: First Downs Allowed – Cornerbacks

| January 28, 2013

For five seasons Pro Football Focus has been dedicated to breaking down the NFL on a play-by-play basis like no other. Speaking for the rest of the staff that has meant long hours and an inability to make full use of all the data we create.

Only now the 2012 season is coming to a close, and with PFF more developed, are we starting to really delve into some revealing numbers. The upshot? Shiny, brand new Signature Stats available for discussion before they even hit the premium website — Signature Stats like this one:

First Downs Allowed in Coverage

It’s a relatively simple concept. We wanted to see which cornerbacks not only gave up the most first downs or touchdowns, but also who gave up the most relative to how often they’re in coverage. After all, someone in coverage for 500 snaps is infinitely more likely to give up results to the offense than a player in coverage for 300.

Now to the data.

Chain Movers

Where better to start than the raw numbers showing who gave up the most first downs? In that respect, the first walk of shame belongs to Sean Smith, who was beaten for 40 first downs and six touchdowns in 2012. Those 46 combined first downs and touchdowns were one more than Cary Williams and Patrick Robinson, both of whom had 45 as their magical number. How about that, two of the three are about to be free agents. Interesting.

 

Name
1st Downs
Touchdowns
1st Downs & TDs
Sean Smith40646
Cary Williams39645
Patrick Robinson36945
DeAngelo Hall41344
Corey Webster35843
Antoine Cason38543
Dunta Robinson38442
Quentin Jammer34842
Josh Norman38240
Cassius Vaughn35540
Tramon Williams38240

 

Per Snap Struggles

However, as I said earlier, how can we really judge those guys given their opportunity to give up first downs are widely different to others? So instead of looking at who gave up the most, let’s look at who gave up the highest percentage relative to their coverage snaps (with a minimum of 300 snaps in coverage).

Well, that man would be the Carolina Panthers’ Josh Norman. Life is rarely easy in the NFL, and when you’re a fifth-round rookie thrust into a starting lineup things can go wrong. Norman gave up a first down or touchdown on 8.95% of his coverage snaps, earning his -7.4 coverage grade for the year. Still, rookies will be rookies, and his career won’t be defined by this season.

The man with the second-highest rating is a far more interesting case. With his numbers added up for the two teams he played for Aqib Talib, often tasked with manning up with a team’s best receiver, allowed a first down or touchdown on 8.75% of plays. He may be incredibly talented, but don’t be thinking he’s a shutdown cornerback when you go to pay him.

 

Name
Snaps
1st Downs & TDs
1st Downs & TDs by Snap
Josh Norman447408.95%
Aqib Talib343308.75%
Cassius Vaughn472408.47%
Joselio Hanson332278.13%
Nolan Carroll415337.95%
Cortez Allen340277.94%
Cary Williams578457.79%
Dunta Robinson540427.78%
Buster Skrine451357.76%
Josh Robinson451347.54%
Derek Cox399307.52%
Corey Webster574437.49%
Eric Wright310237.42%
Sean Smith624467.37%
A.J. Jefferson357267.28%
Patrick Robinson619457.27%
Jimmy Wilson346257.23%
Quentin Jammer589427.13%
DeAngelo Hall625447.04%
Keenan Lewis531376.97%

 

The Shutdown Crew

Still, it’s not all bad. While some guys disappointed, others impressed, and none more so than the 49ers’ left cornerback in their nickel package, Chris Culliver. He gave up a first down or touchdown on only 3.45% of his snaps in coverage, a staggeringly low amount when you consider that the next lowest score is that of Leon Hall, with 3.75%.

 

Rank
Name
Snaps
1st Downs & TDs
1st Downs and TDs by Snap
1Chris Culliver493173.45%
2Leon Hall507193.75%
3Sam Shields342144.09%
4Prince Amukamara434184.15%
5Casey Hayward433184.16%
6Champ Bailey586254.27%
7Adam Jones414184.35%
8Antonio Cromartie527234.36%
9Kareem Jackson635284.41%
10Alterraun Verner579264.49%
11Robert McClain379184.75%
12Chris Houston541264.81%
13Richard Sherman590294.92%
14Brandon Browner446224.93%
15Josh Wilson658335.02%
16Brandon Flowers436225.05%
17Chris Harris Jr.493255.07%
18Antoine Winfield609315.09%
19Kyle Wilson511275.28%
20Asante Samuel472255.30%

 

Sometimes it’s not just about the yards you give up, but the impact of those yards. Do they move the chains or don’t they? There’s a big difference between allowing a 9-yard completion on 3rd-and-10, or giving up a 3-yard completion on 4th-and-2. So looking into who’s giving up touchdowns and first downs is a real indicator of which cornerbacks are truly shutdown.

Stay tuned for more stats like this as the PFF Signature Stat area continues to grow.

 

Follow Khaled on Twitter: @PFF_Khaled

  • http://pulse.yahoo.com/_SPDBNJBVID2QI63SVWQIKLGO3M rene

    Fitting that the Dolphins have three corners in the bad boy list.  That team has been rebuilding for 5 years and still doesn’t have much talent.

    • Anthony Famiglietti

      That’s because Sean Smith is a press corner, Nolan Carroll is more of a zone corner and Jimmy Wilson is a converted safety. After they traded Vontae Davis and Richard Marshall hurt his back Miami was forced to play mismatched corners in a mismatched scheme. That having been said Sean Smith spent most of the year shadowing opposing number 1 receivers, guys like Andre Johnson and AJ Green. And with their safeties both placing in the top 5 (while the pro bowl safeties were in the bottom 10) Miami’s corners saw a lot of passes thrown at them. I also cannot stress enough that after they settled into a scheme in the second half of the season Miami gave up 210.25 yards per game. That includes both games against Brady. Oh and Miami just had four players on the field at the Pro Bowl and had four others in Jones, Clemons, Fields and Pouncey get snubbed who deserved to go as well.

    • Emmett Buck Stiernagle

      Miami has been in the top of the league for least passing td’s for a few years now, do research before you make stupid comments

  • carl

    Culliver is a beast. Where would you say he could improve his game, Khaled? I think his work vs backshoulder throws could use improvement.

  • Galerus

    Thanks, but I think that is someway misguided stats. ‘Cause some CBs may be targeted more often than others and snaps don’t answer the question about their defensive skills on play-by-play basis. May be it is better to count percentage of thrown at them balls?
    Sean Smith, Keenan Lewis and DeAngelo Hall had to defend crazy amount of times, while Chris Culliver had about 66% of their numbers, and Shields about 33%!

    p.s. Just for example look at young-nobody Keenan Lewis and mega-star Camp Bailey. They got almost comparable number of snaps (531 and 586 respectevely). Bailey got slightly more snaps which in your study favors him. but look at number of passes thrown at them – 112 to Lewis and just 74 to Bailey. Despite fewer snaps Lewis was more offen involved in defending situation and all considered he has a little bit better results in 1stD-TD percentage in that regard – 33,0 to 33,8.
    I understand that my piont got flaws ’cause sometimes CBs prevent passes from throwing in their ways by good coverage, but we don’t know that for sure. And thrown passes are sure thing.

    Thanks :)

  • Tplum

    If this is a Signature Stat why don’t I see it when I look at signature stats?

  • Simbic46

    The amout of pressure put on the Qb has a lot to do with it also.

  • McGhee

    Can we get an exact breakdown of how this stat works? Does it only count plays that the player was directly involved. For example, does Champ Bailey get a TD on his stat here if another CB allows a TD while he is on the field? Or is it only counted against him if the player he is covering gets a TD/1st down? Does it take in account of the safety blowing coverage and allowing a WR to go deep when Bailey is playing zone? Just would like a detailed explanation on what terms are being held against these players.

  • http://profile.yahoo.com/IDSH77MQBRZUMIC4SGVF5LYGCM Mike Jones

    not sure that is this is very useful.
    would like to see a breakdown that involved targets and percentage of snaps covering the opposing teams #1 receiver.

  • http://www.facebook.com/mike.nelson.165685 Mike Nelson

    some are targeted more because they are weak