This season I have been tracking some of the top CBs in football. Using coaches film, I look at every single pass play the CB was involved in, and determine whether or not they did their job in coverage. This project was inspired by Cian Fahey (I think he is a BR writer/draftnik now?) who did a similar project a few years back, as he found that even the advanced targets and catches CB metrics many sites began putting out did not tell the whole story. Who were they covering? Was it actually their fault? Were they benefiting from poor QB play?
A couple of notes about my process:
For every eligible pass play, a CB either receives a "Success", "Shutdown" or "Failure" if he's in man coverage, or a "Good", "Great" or "Poor" if he's in zone. This is fairly subjective by its' nature, but I obviously try my best to be consistent. I do take into account situations, a CB is not going to get a "Failure" if the QB has 7 seconds to throw and hits the WR for a 10 yard gain who comes running back towards the QB after finishing his route. Letting up a 9 yard curl on 3rd & 10 is not a failure in the 1st quarter, but 4 down territory in the 4th quarter? It would be. Hopefully you get the gist.
CB gets beat by the WR, in other words, the WR gets in position where a completion can be reasonably expected to occur. Whether it does or not is irrelevant.
WR is able to run most, if not all, of his route but is unable to achieve a position where a completion can be reasonably expected to occur.
WR is able to run his entire route, but the CB remains in a position throughout where a completion would be next to impossible to occur.
CB leaves his zone open long enough that a completion could be reasonably expected to occur, or if CB is simply beat by WR in his zone.
CB does his job, covers his zone, and prevents any good looks from occuring in his zone.
Varies. Generally if multiple WRs cross into the CBs zone, aka it's a difficult play for the CB, but he holds it down, or if the CB shuts down the WR entering his zone.
Ah, speaking of man and zone coverage, that is another tricky part of all of this. I am not a football expert, and even if I was, I would not be able to truly know what a CB's responsibility on any given play was without seeing the playcall. Fortunately when it comes to man coverage, their responsibility is blatant, but it becomes a lot murkier in zone. All I can say is I try my best and look at the context of any given play, but when it comes to zone, those are the numbers I have the least confidence in. For some teams (Jaguars) who play plenty of man and zone, even determining whether that CB is playing man or zone can be tricky. For other teams (Vikings), it is very clear from the get go what type of coverage they're running. Personally I use a couple of cues to determine what coverage I believe a CB is in: hip direction, where the CB is looking, and what the rest of the defense is doing.
I mentioned eligible pass plays earlier, let me elaborate. I look at every pass play, but I don't judge the following pass plays
Designed quick passes. You can often tell if a QB is making 1, or no, reads after the snap. You see it a lot on goal line fades, are in the flat to the HB if the QB identified a hole pre-snap. I'm not crediting a CB for good coverage when the ball got out in 1 second and the QB didn't even look the way of the CB, UNLESS the CB's man is the target on that play, as then I am judging your coverage with the ball in the air.
Zone coverage where all pass catchers converge to the opposite side of the field.
With that out of the way, let's get to the juicy stuff, the stuff that I think people will find more value in and are more interested by: The charting stats. I've recorded every reception given up, which entails who the WR was, the down distance and quarter, and the general route ran (I go with "general" because WRs do not run their routes as textbook as in Madden!) I am very confident in the accuracy and relevance of this charting data, as there is very little subjectivity, especially when it comes to man coverage, as opposed to the success/fail data which involves more subjectivity.
I have already looked at Rhodes, Lattimore and Ramsey. Currently working on White from the Bills and Mills from the Eagles (I wanted to look at a CB who is not considered great). For the first guy we'll look at, I'm going with Rhodes, as he was the easiest to chart and most enjoyable.
From their second game, and until the end of the season, the Vikings put Rhodes on any notable WRs and had him follow them for over 3/4ths of the game. Rhodes played almost exclusively man coverage, and lot of press, and in my opinion did a tremendous job. Antonio Brown, Julio Jones, Mike Evans, Michael Thomas, AJ Green, all shadowed, and arguably shut down, by Rhodes in 2017. He is an extremely physical, and handsy, CB (definitely gets away with his fair share of holds but nothing egregious). Very quick athlete, when WRs make their break Rhodes seems to just snap himself towards them without missing a beat. Rhodes is definitely at his best when he is up on the line and in position to jam WRs, as it not only lets him get extra physical and mess up their break, but it lets him get into trail technique which he does very well playing. Rhodes makes it clear as day what coverage he is playing, which made my job easier. If he's in zones, he'll have his hips towards the QB pre-snap, if he's in man, he'll be squared up against his WR (and often wrapping his arms around each other). While I've only looked at 3 CBs, I already have a hard time imagining there being any corner play much better than this.
vs Antonio Brown, Julio Jones, Mike Evans, Michael Thomas, AJ Green (5 games)
Allowed just 19 catches on 38 targets for 210 yards. That is an average of 3.8 receptions and 42 yards per game given up in his meetings with who were perhaps the 5 best healthy WRs in the NFL this season.
Allowed a passer rating of just 70.4 while in man coverage. Impressive considering he was more often than not covering the opposing team's best WR.
The Jaguars play a ton of cover 3, and while Ramsey can certainly play zone, I think he is best served in man coverage. Almost every time he got the opportunity to play press man, the WR failed to get any separation, especially on vertical routes. Due to their use of zone, and the fact that they have 2 great corners, Ramsey just stayed on the left side more often than not, but he was given shadow duties many times. Sometimes during key drives down the stretch Ramsey would follow around the opposing #1. It was not always easy to determine what coverage Ramsey was in, and all too often he was asked to play off the WR which doesn't mesh well with this whole system I'm using, making for a lot of judgement calls. Hard to outrun, but susceptible to the double move form shiftier WRs.
Only 1 accepted penalty called on him, and it was in the final game of the season. I recall he was also flagged on a TD he let up to AB, which was declined. Considering how physical he is, that is impressive.
Was directly responsible for 26 incompletions.
QBs had a 54.9 passer rating when throwing to WRs he covered.
Lattimore is just a rookie but already one of league's top flight CBs. Excellent mix of athleticism and size/physicality helped him to seamlessly transition to the NFL at a position that historically has a steep learning curve. On top of being a rookie he dealt with some injuries. He initially stayed on the right side of the field and played more conservative coverage, but by the end of the year he was tasked with following around opposing top WRs and playing a ton of press man. Not quite as explosive as Ramsey or as fluid as Rhodes, makes up for it by already having a knack for reading routes right before they unfold.
No TDs allowed in man coverage. Only 2 TDs allowed overall, 1 of which, that was allowed to Rudolph in week 1, could be argued was not Lattimore's fault.
Prior to ankle injury, allowed just 14 catches for 126 yards over 8 games and 245 cover snaps. Upon returning, he allowed 22 catches for 373 yards over 6 games and 198 cover snaps. Ankle injury could have played a role, as he did appear a bit flat footed, but also worth noting that in all but 1 of those final 6 games he followed opposing top WRs, which included following Julio twice.
Another rookie phenom, White brings great ball skills and positioning to the table. Unlike the other CBs looked at thus far, White was by and large a zone cornerback in 2018. The Bills primarily played basic cover 2 and cover 4, with White manning the left side and rarely moving. He did a great job in his role, but it was pretty limited as he was essentially asked to simply back pedal and occupy space, more or less, and hope the pass rush could force an errant throw. Got more comfortable in his role as the year went on and rarely had miscommunications or missed assignments in zone. Probably made his zone coverage look easier than it was. Can be physical, and lined up across from TEs later in the season on occasion, despite his slender frame.
Faulted for only 13 catches for 193 yards and 0 TDs, while grabbing 3 INTs and drawing 0 flags in final 8 games (not including blizzard game).
Over 60% of counted coverage snaps were in zone.
Good tackler, allowed just 3.5 YAC per catch allowed.
One of the trickiest CBs to track yet as his stance in man and zone coverage appeared to be the same and he always tended to have his eye on the QB (normally tell-tale sign of zone) even in what I could only deduce were man situations (no safety help, other CBs playing clear man, etc.). Peters sets himself apart from the other CBs as an extraordinary playmaker, even on routine tackles he is going for the rip more often than not. QBs often overthrew his targets in what I assume were attempts to throw a ball in a place where only the WR could catch it out of fear of Peters. He generally gave his man an 8+ yard cushon, although as the season winded down he was lining up right off the LOS more and more. Regardless of how he lined up, Peters often immediately bailed and would start back pedaling off the snap, letting the WR reach him or even get a step on him, before entering a trail technique. I would say this is all just part of his game as playmaking CB constantly looking to bait the QB. There were only a handful of plays where he jumped routes he shouldn't have and could have allowed major gains, and only a few actually came to be. Chiefs ran a ton of cover 1, and surprisingly I would say the single high safety shaded toward Peters' side more often than not, but honestly I did not track that and could be wrong; though I will say at the very least he certainly wasn't being left on an island.
Allowed opposing passer rating of 44.8, lowest recorded yet.
Lined up almost exclusively at LCB on plays I counted.
Allowed just 1 TD and picked off 5 passes in final 10 games.