Cornerbacks: Cover Snaps Count

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With the limits of television footage, it would be an accurate statement to say cornerback is the trickiest position for those outside of NFL teams to analyze.

That, however, hasn’t stopped the discussion and people are finding new ways to help us all better understand CB play. In recent years, advanced stats such as those provided by this site, have added to this. The use of stats such as pass break ups, times thrown at, and yards allowed have all contributed in this regard, but it’s always missing a degree of context.

Has a guy who has been thrown at 80 times and allowed 60 receptions necessarily been more of a target than a player who was thrown at 60 times and allowed 45 receptions? There’s an important piece of information missing and it’s this extra level of context that we search for at Pro Football Focus, aiming to enhance discussion on all things NFL.
 

So, by way of our game analysis process, we’re bringing you something that will push things a step further. A simple enough premise, we’ll look at how often a cornerback is thrown at and how many receptions he allows compared to how many snaps he has spent in coverage.
 
Up first, we’re checking out the percentage of plays in coverage that corners were thrown at. For this study we looked at all cornerbacks who were in coverage for at least 300 snaps (playoffs included), and it’s no surprise who has been targeted least often: Nnamdi Asomugha.
 
When it comes to having a reputation that QBs fear, there isn’t another player like the soon to be free agent. He was targeted on just 6.58% of the 441 plays he was in coverage. Perhaps more of a surprise is that Miami’s Sean Smith winds up in second place. There are some mitigating circumstances as Smith spent time in the safety spot in their third down nickel defense. Still, it’s reflective of the ability Smith has shown, though his inability to turn break-ups into picks impacts the common view on him.
 
Others in the Top 5 you would expect to see include Asante Samuel and Darrelle Revis. With Samuel, you worry about throwing the ball to him because he’s the kind of playmaker who can turn a game around in one play. Revis, on the other hand, allows so little that it’s not so much a risk to throw in his direction as it’s a pointless exercise. After 2009, where he was thrown at on a staggering 18.27% of plays he was in coverage, teams seemed to realize that was a foolish strategy and the number dropped to 10.32% in 2010 (even with him playing hurt part of that time).
 

Top 20 Cornerbacks, Times Thrown At per Coverage Snaps

Rank	Player	Team	Cover Snaps	Thrown At	TA/COV
1	Nnamdi Asomugha	OAK	441	29	6.58%
2	Sean Smith	MIA	448	44	9.82%
3	Asante Samuel	PHI	446	46	10.31%
4	Darrelle Revis	NYJ	592	67	11.32%
5	Rashean Mathis	JAX	567	66	11.64%
6	Shawntae Spencer	SF	622	77	12.38%
7	Chris Gamble	CAR	377	47	12.47%
8	Kelly Jennings	SEA	625	78	12.48%
9	Sam Shields	GB	543	68	12.52%
10	Vontae Davis	MIA	566	72	12.72%
11	Joselio Hanson	PHI	450	58	12.89%
12	Leon Hall	CIN	563	74	13.14%
13	Ike Taylor	PIT	763	102	13.37%
14	Champ Bailey	DEN	489	66	13.50%
15	Quentin Jammer	SD	576	78	13.54%
16	Bradley Fletcher	SL	601	82	13.64%
17	Ronde Barber	TB	515	71	13.79%
18	Charles Woodson	GB	658	91	13.83%
19	Corey Webster	NYG	576	81	14.06%
20	Kyle Arrington	NE	533	75	14.07%

 

At the other end of the scale, we see some interesting names. Not too surprisingly given how often they’re likely to be targeted on shorter routes over the middle, a number of slot cornerbacks find themselves in the mix. There are, however, a number of starters ranking lowly as well. Players like Brent Grimes and Bryant McFadden both found themselves the guys in the firing line, though they dealt with it in different manners: Grimes managed to make plays on the ball, finishing second in pass deflections, while McFadden ended with a -6.1 grade in coverage.
 

Bottom 20 Cornerbacks, Times Thrown At per Coverage Snaps

Rank	Player	Team	Cover Snaps	Thrown At	TA/COV
64	Antoine Cason	SD	562	100	17.79%
65	Michael Adams	ARZ	359	64	17.83%
66	Leodis McKelvin	BUF	443	80	18.06%
67	Stanford Routt	OAK	548	99	18.07%
68	Jabari Greer	NO	498	90	18.07%
69	Greg Toler	ARZ	524	95	18.13%
70	Derek Cox	JAX	401	74	18.45%
71	E.J. Biggers	TB	438	81	18.49%
72	Alphonso Smith	DET	346	64	18.50%
73	Bryant McFadden	PIT	642	120	18.69%
74	Javier Arenas	KC	390	74	18.97%
75	Brent Grimes	ATL	668	127	19.01%
76	Orlando Scandrick	DAL	401	77	19.20%
77	Drew Coleman	NYJ	385	74	19.22%
78	Glover Quin	HST	607	117	19.28%
79	Perrish Cox	DEN	435	84	19.31%
80	Lardarius Webb	BLT	434	85	19.59%
81	Terrell Thomas	NYG	615	124	20.16%
82	Dimitri Patterson	PHI	402	84	20.90%
83	Jerraud Powers	IND	317	78	24.61%

 

While it’s interesting to see who is targeted the most, it’s more relevant to look at how many receptions a cornerback allows while they are in coverage. In other words, you may be targeted a lot, but if they’re not resulting in anything, then so what. Revis’ 2009, as an example.
 
In something that will come less of a surprise, up at the top again is Nnamdi Asomugha.  Even when quarterbacks get brave enough to throw at him, it’s not likely to end up in a completion.  Similar stories for Asante Samuel and Darrelle Revis, with the most interesting stories coming from guys making this top ten list after not making the targets per coverage snaps list.
 
Despite being targeted on 15.53% of plays he was in coverage, Green Bay’s Tramon Williams allowed a reception on just 7.07% of plays he was in coverage.  Similarly, Josh Wilson moved from 43^rd in terms of how much he was targeted, to ninth in terms of receptions allowed when looking at how many snaps he was in coverage.
 

Top 20 Cornerbacks, Receptions Allowed per Coverage Snaps

Rank	Player	Team	Cover Snaps	Receptions Allowed	REC/COV
1	Nnamdi Asomugha	OAK	441	13	2.95%
2	Asante Samuel	PHI	446	21	4.71%
3	Darrelle Revis	NYJ	592	28	4.73%
4	Sean Smith	MIA	448	24	5.36%
5	Rashean Mathis	JAX	567	39	6.88%
6	Quentin Jammer	SD	576	40	6.94%
7	Bradley Fletcher	SL	601	42	6.99%
8	Tramon Williams	GB	792	56	7.07%
9	Josh Wilson	BLT	451	32	7.10%
10	Sam Shields	GB	543	39	7.18%
11	Brandon Carr	KC	700	51	7.29%
12	Kelly Jennings	SEA	625	46	7.36%
13	Tim Jennings	CHI	621	46	7.41%
14	Ike Taylor	PIT	763	57	7.47%
15	Corey Webster	NYG	576	44	7.64%
16	Stanford Routt	OAK	548	42	7.66%
17	Chris Gamble	CAR	377	29	7.69%
18	Champ Bailey	DEN	489	38	7.77%
19	Leon Hall	CIN	563	44	7.82%
20	Vontae Davis	MIA	566	45	7.95%

 

Meanwhile, those suffering the biggest drops include Richard Marshall who went from 53^rd in targets per coverage snaps, to 78^th in receptions allowed per snaps in coverage. Some of this is down to Marshall moving inside in nickel situations (a study we’ll be looking to do in the future), but it remains an alarming fall, and not in line with other starting cornerbacks who move into the slot in their team’s sub package such as Charles Woodson or Ronde Barber.
 

Bottom 20 Cornerbacks, Receptions Allowed per Coverage Snaps

Rank	Player	Team	Cover Snaps	Receptions Allowed	REC/COV
64	Fabian Washington	BLT	312	35	11.22%
65	Eric Wright	CLV	382	43	11.26%
66	William Middleton	JAX	319	36	11.29%
67	Johnathan Joseph	CIN	371	42	11.32%
68	Michael Adams	ARZ	359	41	11.42%
69	Jacob Lacey	IND	400	46	11.50%
70	D.J. Moore	CHI	446	52	11.66%
71	Jabari Greer	NO	498	59	11.85%
72	Glover Quin	HST	607	73	12.03%
73	Alterraun Verner	TEN	604	73	12.09%
74	Lardarius Webb	BLT	434	53	12.21%
75	Terrell Thomas	NYG	615	76	12.36%
76	Alphonso Smith	DET	346	43	12.43%
77	Bryant McFadden	PIT	642	81	12.62%
78	Richard Marshall	CAR	577	73	12.65%
79	Drew Coleman	NYJ	385	49	12.73%
80	Javier Arenas	KC	390	50	12.82%
81	Dimitri Patterson	PHI	402	53	13.18%
82	Orlando Scandrick	DAL	401	53	13.22%
83	Jerraud Powers	IND	317	51	16.09%

 

Of course, these aren’t numbers you can blindly look at and say that because a player is being targeted less, or allowing fewer receptions he’s a better player. There are a number of other factors to consider. Take the cornerbacks of the NFC West for example, are you really going to say their receptions allowed per time in coverage doesn’t benefit from having a division somewhat lacking in quality QB play? Or that a cornerback playing for the Packers doesn’t benefit from their high sack count. Then, of course, there are players who are targeted more because their teammates are just that good.
 
When Champ Bailey’s Bronco partner Perrish Cox was in the lineup, teams went after him.  Oakland’s Stanford Routt was targeted on 18.07% of all plays with teams looking at him as a safer option than Asomugha. Dunta Robinson’s contract seemed to scare people into believing he was better than he performed, with the playmaking Brent Grimes the guy seeing more action.
 
Let’s pause on Grimes for a minute, he’s an interesting one. Targeted on 19.01% of the plays he dropped into coverage (74^th out of 83), he only allowed receptions on 10.03% and finished second in the league in combined pass deflections and interceptions. Top it with a +7.5 coverage grade, and you have to think that next year teams may shy away and start looking more towards Robinson (who didn’t perform badly, but didn’t exactly earn his mega contract).
 
Looking from the opposite point of view, maybe you’ll expect Shawntae Spencer (targeted on just 12.38% of plays in coverage) to get more treatment after allowing 70.1% of the balls thrown his way to be completed (part of what earned him a -4.5 coverage grade).
 
Ultimately, these numbers are a little offseason fun. They tell us some things we already knew (teams don’t throw at Asomugha, Samuel and Revis if they can help it) and some things we didn’t (they also don’t throw at Rashean Mathis, Sean Smith and Bradley Fletcher).
 
The real value in them is that they add to the discussion about cornerback play.  You can’t truly judge a cornerback and his metrics, without looking at how many times he dropped into coverage.  Even that doesn’t offer as much as grading, but as said, it just adds more context to the debate.
 
So take these number under advisement, but don’t jump to conclusions over all of them … though it is fair to say that Scrabble remains a game quarterbacks don’t like to play.
 
______________
 

We’ll leave you with one further look. Combining the tables above to we can illustrate a mashed-together view of each qualifying corner’s times beaten (receptions allowed), times challenged (thrown at), and challenge opportunities (snaps in coverage) – effectively, catch % per cover snap.
 
Asomugha doesn’t rule this one, as he ranks relatively lower on challenges and challenge opportunities. Players that managed to keep their catch percentage under 50% while racking up higher coverage snap counts like Tramon Williams, Brandon Carr, and Antonio Cromartie benefit.
 
The number itself is rather odd to look at and could be tweaked to be more glance-friendly, but here it is in raw form:
 

Top 20 Cornerbacks, Catch Percentage per Coverage Snaps

Rank	Player	Team	Receptions Allowed	Thrown At	Cover Snaps	Catch% per Cover Snap
1	Tramon Williams	GB	56	123	792	0.0575%
2	Brandon Carr	KC	51	111	700	0.0656%
3	Antonio Cromartie	NYJ	55	115	683	0.0700%
4	Darrelle Revis	NYJ	28	67	592	0.0706%
5	Ike Taylor	PIT	57	102	763	0.0732%
6	Stanford Routt	OAK	42	99	548	0.0774%
7	Brent Grimes	ATL	67	127	668	0.0790%
8	Charles Tillman	CHI	67	111	751	0.0804%
9	Brandon Flowers	KC	55	109	625	0.0807%
10	Tim Jennings	CHI	46	91	621	0.0814%
11	Devin McCourty	NE	58	104	685	0.0814%
12	Bradley Fletcher	SL	42	82	601	0.0852%
13	Chris Carr	BLT	62	100	699	0.0887%
14	Quentin Jammer	SD	40	78	576	0.0890%
15	Antoine Cason	SD	52	100	562	0.0925%
16	Cortland Finnegan	TEN	70	105	713	0.0935%
17	Charles Woodson	GB	56	91	658	0.0935%
18	Corey Webster	NYG	44	81	576	0.0943%
19	Kelly Jennings	SEA	46	78	625	0.0944%
20	Ronald Bartell	SL	50	96	548	0.0950%

 

Bottom 20 Cornerbacks, Catch Percentage per Coverage Snaps

Rank	Player	Team	Receptions Allowed	Thrown At	Cover Snaps	Catch% per Cover Snap
64	Tracy Porter	NO	43	66	434	0.1501%
65	Carlos Rogers	WAS	50	72	462	0.1503%
66	Dimitri Patterson	PHI	53	84	402	0.1570%
67	Chris Gamble	CAR	29	47	377	0.1637%
68	D.J. Moore	CHI	52	71	446	0.1642%
69	Aqib Talib	TB	35	59	357	0.1662%
70	Orlando Scandrick	DAL	53	77	401	0.1716%
71	Drew Coleman	NYJ	49	74	385	0.1720%
72	Kelvin Hayden	IND	38	58	380	0.1724%
73	Eric Wright	CLV	43	65	382	0.1732%
74	Javier Arenas	KC	50	74	390	0.1733%
75	Johnathan Joseph	CIN	42	64	371	0.1769%
76	Michael Adams	ARZ	41	64	359	0.1784%
77	Jason McCourty	TEN	31	52	322	0.1851%
78	Justin Tryon	IND	38	60	342	0.1852%
79	Jacob Lacey	IND	46	62	400	0.1855%
80	Alphonso Smith	DET	43	64	346	0.1942%
81	Jerraud Powers	IND	51	78	317	0.2063%
82	Fabian Washington	BLT	35	51	312	0.2200%
83	William Middleton	JAX	36	49	319	0.2303%