Writers of Pro Football Prospectus 2008

12 Jan 2010

Stat of the Day: Top 10 CB in Run Plays

Mike Tanier and I were talking last week, and he made a good point: At this point, FO has compiled so many stats that we've got a ton of interesting numbers that we don't even get a chance to use. We've game charting, we've got the specific special teams material, we've got the individual defense stuff... a lot of these numbers are automatically compiled for the 2009 season and stay sort of hidden until we use some of them in playoff previews or in Football Outsiders Almanac 2010.

This stuff shouldn't stay hidden. There are a lot of really interesting numbers that help tell us which teams and players were particularly good or bad in 2009. Numbers also help show us how teams played, what their schemes looked like and what the strengths and weaknesses of those schemes are.

So in that spirit, I hereby pledge to run a new stat list on Football Outsiders every weekday until Super Bowl XLIV. They won't necessarily come with commentary -- I'll leave that to the reader discussion -- but I want to share with all the readers some of the information we don't necessarily update on the site each week.

To start, in honor of Charles Woodson getting voted Defensive Player of the Year, here's the list of the top 10 cornerbacks in run Plays this year. Plays means any time a player is mentioned in the standard play-by-play, so both solo tackles and assists. In general, players in zone coverage will appear higher on this list, and Green Bay's move to a more zone-based scheme this year is a reason for Woodson's strong year, although someone then had to explain why Tramon Williams made only five run tackles all season. The one player above Woodson is quite a surprise, and I never would have guessed the name without seeing the numbers.

By the way, I've noted recently that Woodson was second in the league in run tackles; stat changes by the league moved Ronde Barber ahead of him, so he's now third.

Terrell Thomas, NYG: 40
Ronde Barber, TB: 36
Charles Woodson, GB: 35
Reggie Corner, BUF: 27
Drayton Florence, BUF: 26
Brandon Flowers, KC: 25
Glover Quin, HOU: 24
Richard Marshall, CAR: 22
Cedric Griffin, MIN: 22
Derek Cox, JAC: 22

Oh, and for those wondering, Darrelle Revis had 20 run Plays. Nnamdi Asomugha had 19, which means he actually had more tackles on runs than he did after complete passes (15).

Posted by: Aaron Schatz on 12 Jan 2010

31 comments, Last at 14 Jan 2010, 8:34am by Packer Pete


by Packerpalooza (not verified) :: Tue, 01/12/2010 - 12:15pm

Woodson is incredibly tough as he throws his body around with abandon. He also must have very strong hands as he dragged down running backs with one hand that had already brushed off a defensive lineman's attempt at a tackle.

His shoestring tackle at the goal line against the Ravens was beyond awesome.

by Grant (not verified) :: Wed, 01/13/2010 - 4:42pm

That was a play that separates the men from the boys. Woodson flew through the air - knifing his way through offensive linemen - to land flat on his face and get only the ankle of hard running Ray Rice with one hand. Not the hardest tackle you'll see, but one that perfectly showed the intangibles of Woodson. Not too many guys make a tackle like that - or even attempt it.

by Formersd (not verified) :: Tue, 01/12/2010 - 12:22pm

Both Buffalo CBs are here (#4/#5). I'm thinking that's more a product of the front seven than the tackling abilities of Corner and Florence.

by Aaron Schatz :: Tue, 01/12/2010 - 12:23pm

BUF corners have been high in run tackles for a couple years for both that reason and the fact they play a lot of zone.

by ammek :: Tue, 01/12/2010 - 1:31pm

Do you keep tabs on the number of missed tackles by cornerbacks? Barber must rank high on that list too.

by Hurt Bones :: Tue, 01/12/2010 - 6:26pm

Domonique Foxworth would be near the top of that list.

by Bvandy (not verified) :: Tue, 01/12/2010 - 11:17pm

Assante Samuel was #1 w/ 19 missed tackles. Barber was #2 with 16. Foxworth was #4 with 11 missed tackles.

by andrew :: Tue, 01/12/2010 - 12:22pm

Winfield was hurt much of the year, but wonder where he was before and after his injury...

by Bill Prudden (not verified) :: Tue, 01/12/2010 - 12:33pm

Aaron -

Could you tell us, with Reevis and Asomugha at 19 and 20 tackles, where that puts them? Top 20?


Bill Prudden

by MJK :: Tue, 01/12/2010 - 12:46pm

I wonder...

One of the big problems in using "tackles" as a metric for how good a CB is is that, in the pass game, "tackles" are generally a bad thing for a CB, because it implies that (1) a receiver near the CB got open, and (2) said receiver caught a ball and hence the CB allowed the offense to gain positive yards. Of course there are exceptions--making a tackle on a -1 yard swing pass is a very good thing and a necessary skill for a corner--but in general, judging a CB by tackles tends to penalize guys like Asomugha because QB's tend to avoid them, and they are often covering the opposing team's best WR and hence not in a position to make tackles in the run game.

But your comment about Asomugha made me wonder if looking at the RATIO of run tackles to pass tackles might be one good metric of evaluating a CB's quality. The fact that Asomugha has more run support tackles than pass tackles could be one indicator that he is a very good CB. Consider:

* A team with a good pass defense will face more run plays, in general (unless they're playing the Eagles), so its CB's will have more opportunities to make run tackles and fewer opportunities to make pass tackles. So conversely, CB's with high run-tackle to pass-tackle ratios are likely on teams with better overall pass defenses.

* Within a given team, assuming the opposing team isn't running a crazily skewed run-pass ratio, the number of run tackles a CB makes should be positively correlated to the number of plays when he is on the field--meaning more run tackles for one CB versus another within a given team's scheme will probably mean the first CB played more than the second. However, more pass tackles for one CB versus another generally means that the first CB was letting his receivers get open more often than the second, meaning he is weaker in pass coverage. So the ratio of pass tackles to run tackles should be correlated to the total number of times a CB let his guy get open in the passing game versus the total number of plays he was on the field.

You still have the problem that zone CB's make more run tackles than man CB's, which would skew things comparing corners across teams (unless you somehow normalized to the number of run tackles the CB's on a given team made the previous year, or something, assuming the team ran the same scheme).

One way to test this hypothesis would be to see if you could calculate the ratio for as large a sample of CB's as is feasible, and see if pass tackle to run tackle ratio is strongly (negatively) correlated to either the quality of their respective team's pass defenses (or specifically to their defense against #whatever receivers), or to said player's salaries (including only CB's that have played a number of years i.e. that aren't still on their rookie deals).

The point of salary would be to assume that NFL personnel departments know who the "good" corners are and good performance is usually rewarded with higher salary.

by Thok :: Tue, 01/12/2010 - 9:21pm

Won't starters almost always have a higher ratio of run tackles/pass tackles than nonstarters? The nonstarters will mostly be used in passing downs (as nickle/dimebacks in 3rd and long situations, for example.)

by The Ninjalectual :: Tue, 01/12/2010 - 10:19pm

assume that NFL personnel departments know who the "good" corners are and good performance is usually rewarded with higher salary

Nate Clements?

"Just look at that pumpkin."
-John Madden, looking at the moon.

by staubach (not verified) :: Tue, 01/12/2010 - 1:18pm

More tackles for many of these CBs could also be a product of playing on teams with poor offenses and/or poor defenses that force them to be on the field more often. A better metric might be the total # of tackles/ # of defensive plays.

by ammek :: Tue, 01/12/2010 - 1:25pm

Thomas and Woodson would still come out well. According to Pro Football Focus, Thomas played 1002 regular-season snaps (14th most among cornerbacks), Woodson 984 (20th). Barber was 4th with 1059.

by BucNasty :: Tue, 01/12/2010 - 3:40pm

Even better would be to only count opposing running plays, like with ASR.

Another reason Barber could have high run tackles, besides playing a lot of zone on a bad team that probably faced more runs than average, is that he blitzed a lot. In particular, he blitzes out of nickel, so not only are there less linebackers but he's right over the line. He's also pretty good at it.

by ammek :: Tue, 01/12/2010 - 1:21pm

Woodson's stat should probably come with an asterisk, since in the middle part of the season at least he was lining up at safety as much as cornerback.

I believe the same thing was true for Terrell Thomas.

by JasonK :: Tue, 01/12/2010 - 1:42pm

No, Thomas started at CB all season. Aaron Ross was the CB who the Giants tried to play at S later in the season. Ross was supposed to be the starter at RCB, but had lingering muscle injuries (either hammy or quad, I forget which) that kept him out of the lineup for most of the year. Plus, Thomas' play justified his keeping the starting CB spot when Ross retured. He was the best DB on the team in 2009.

I think Thomas' run tackle total is at least partly a function of him being the RCB in the base defense. The Giants D was weakest on runs to the offensive left (injuries at WLB + Osi taking too many wide-angle rushes = 31st in ALY around Left End), so runs to that side often had to be cleaned up by the secondary. Thomas also played the slot in the nickel defense, which is the CB most likely to be in on running plays in that formation.

by E :: Tue, 01/12/2010 - 2:46pm

Your notes about Thomas' position (offensive left, sometimes slot) are true, but I'm sure that the same could be said of many CBs in the league - on almost every team, someone has to be playing on the defense's weak side and some corner will have an inordinate number of opportunities to make tackles. Thomas stepped up and made those plays.

I'm not that surprised to see Thomas at the top of this list (I wouldn't have guessed it, but it doesn't seem out of line either). I'd go further than saying he was the best DB on the team in 2009. In a year when the Giants D was porous, I think he was the best defensive player on the team. #1 in the league in run tackles by a CB, and he was decent in coverage too even though his safety "help" came from CC Brown, Aaron Rouse and Michael Johnson.

by Mr Shush :: Tue, 01/12/2010 - 9:38pm

I was a big fan of Thomas coming out of college, and hoped the Texans would draft him (CB having been a perennial major need since before Kubiak was hired). I particularly remember him having a great game against Brady Quinn/Jeff Samardzija era Notre Dame, shutting Samardzija down pretty comprehensively. I'm glad to see he's doing well in New York.

by Packer Pete (not verified) :: Thu, 01/14/2010 - 8:34am

I don't recall Woodson ever lining up at safety alongside Nick Collins. Woodson often moved to the slot receiver or covered the tight end, putting him almost in a linebacker position when the ball was snapped, but I don't think he lined up in a deep safety position, certainly not for an entire game.

by Will Allen (not verified) :: Tue, 01/12/2010 - 2:08pm

Percentage of tackles, run or pass, short of the first down stick would be an interesting number, or, even better, percentage of tackles resulting in an unsuccessful offensive play, by DVOA definition.

by JasonK :: Tue, 01/12/2010 - 2:18pm

In other words, the "Stop Rate" stat that appears in PFP/FOA.

by TTP (not verified) :: Tue, 01/12/2010 - 2:21pm

Right. Raw tackle totals really don't tell us anything about a particular individual (other than the number of tackles made, of course). At the very least, these numbers need to be normalized by opportunity to have any meaning at all.

by Podge (not verified) :: Wed, 01/13/2010 - 6:07am

I think Yards After Catch allowed is a decent stat for evaluating corners - a corner who doesn't allow many yards after the catch on passes when he is in coverage can probably generally to be assume to be decent in coverage to be close enough to the guy to make a tackle, and at actually tackling the guy.

by Dean :: Tue, 01/12/2010 - 2:50pm

Given that corners generally line up wide and given that their primary responsibility is coverage on WRs, it's not feasible to see them making tackles inside the proverbial box.

Ammek above made a good point about wondering about missed tackles.

I'd like to see the number of plays into the flat on a given CBs side of the field - screen passes, sweeps, off tackle runs, end-arounds, etc. - to see how many times a CB had an opportunity to make the tackle, and then use that number as a denominator in a tackle/opportunity ratio.

by Roger Cossack (not verified) :: Tue, 01/12/2010 - 3:49pm

I think Beanie Wells can explain why Tramon Williams made only five run tackles all season. Amirite?


by tom barone (not verified) :: Tue, 01/12/2010 - 4:34pm

Terrell Thomas proves that at least someone on the giants defense made a tackle on a run play.

by zenbitz (not verified) :: Tue, 01/12/2010 - 5:25pm

Note distinct lack of "run stopper" Nate Clements, although he did miss the last few games.

by greybeard :: Tue, 01/12/2010 - 8:49pm

And with "last few games" you mean last 10 games. Shame on him not to do in 6 games what others did in 14-16 games.

by dk240t :: Tue, 01/12/2010 - 5:48pm

Wow. Glover Quinn, Houston's rookie 4th round CB? I don't even think he started the first half of the season.

I'd like to see that on some sort of rate or per-play basis.

by Dr. Mooch :: Wed, 01/13/2010 - 10:40am

I'd really, really like to see additional exploratory statistics on this. My first hope would be that we have some game charting on missed tackles. Given that, I'd like to see several percentages: 1) run tackle rate (run tackles/run plays for which the player was on the field), 2) in on play rate ([run tackles + missed run tackles]/run plays for which the player was on the field), and 3) a sort of tackle effectiveness (run tackles/[run tackles + missed run tackles]).