Through the long history of the NFL, offenses and defenses have engaged in cycles of attack and retreat. There's been a Bear Front for every Wing-T, a zone blitz for every West Coast concept. And lately, from the high school level up, offenses are stretching the field to its figurative breaking point, and defenses to their literal breaking points, with multi-receiver sets and motion that would have been inconceivable a generation ago. In the last decade, NFL offenses have adopted ideas from college spread offenses and put them to use in record-setting displays of scoring and tempo. In response, NFL defenses are pulling linebackers and defensive linemen off the field to use extra defensive backs -- and they're not just doing it on obvious passing downs. In fact, you could say that the specialized passing defenses of yesterday's NFL are the base defenses of today -- and tomorrow.
In 2011, NFL teams lined up with three or more receivers 49 percent of the time, per Football Outsiders' charting metrics. In 2012, that number climbed up to 51 percent, and last season, it rose to 56 percent. A future in which the three-receiver set is the norm has arrived. Correspondingly, defenses have upped their usage of nickel defenses, the set in which five defensive backs patrol the field (generally at the expense of a formerly indispensable linebacker). Teams ran base (with four defensive backs) 48 percent of the time in 2011, 45 percent in '12 and 40 percent in '13. Nickel sets increased from 40 to 44 to 49 percent over that same three-year span. Nickel is the new base defense, a changing of the guard that was an inevitable offshoot of an uptick in offensive creativity.
Double Nickels on the Dime: The new reality
Seattle Seahawks head coach Pete Carroll, who's coached defenses in various forms and fashions since the 1970s, recently told me that the idea of a fifth defensive back as more than a fifth wheel isn't really new -- but it's certainly a recent point of focus.
"Teams are more apt to be wide open in general [on offense], so there will be more numbers," he said. "But the third-down stuff and the nickel stuff has always been important, and that nickel cornerback was always important. Or the safety coming off the bench, or the cover linebacker you use. That's been around a long time.
"There's been so much passing game in the last 10 years, and I think the nickel -- it's half the game. Half the game, you're in nickel or some kind of substitution defense. So, it's whichever way you want to look at it; maybe that's base and the other part is substitution now. We're divided about 500 plays to 500 plays year in and year out, and it's a big deal. That's why [on defense], we have more than 11 starters. We've got 15-16 starters that we see, and you can tell, depending on the opponent and the situation in the game, how many of those guys we'll move in and out, and feel comfortable doing that."
Vic Fangio, who coaches the defense for Carroll's arch-rival San Francisco 49ers, recently detailed his own take on the importance of the fifth defensive back and who generally pays the price from a snap-weighted perspective.
"That's a position in today's game ... [that] plays a lot. Our starting nose tackles here the last few years, Isaac Sopoaga and last year Glenn Dorsey -- our fifth defensive back has played more than those guys have. You've really got 12 starters on defense [now] -- you've got your 11 in your 3-4 package and when you go to your fifth DB, he's also a starter. That guy has played upward of 60 percent for us in the last few years."
, who play with a 4-2 concept up front a lot of the time, used at least five defensive backs on 59 percent of their snaps last season.
The Broncos will probably use Roby inside and outside, depending on the health of slot corner Chris Harris -- they went with at least five DBs on 69 percent of their defensive snaps last season, and their pass defense took a major hit when Harris was lost for the postseason in the team's divisional playoff win over the Chargers. Harris suffered a torn ACL in the third quarter of that game, with the Broncos up 17-0. Immediately, Philip Rivers went after Quentin Jammer, Harris' replacement, and Denver found itself fighting desperately to eke out a 24-17 win as Rivers abused Jammer with the help of rookie receiver Keenan Allen. Denver took Roby, in part, because there's no margin for error at the slot position anymore.
Building the Perfect Beast: The ideal nickelback
Though some teams implemented three-cornerback and three-safety looks in the 1990s and early 2000s (the Green Bay Packers did so in the Mike Holmgren and Fritz Shurmur era, as NFL.com's Bucky Brooks points out here), a team's slot defender used to be the guy without a true position. Perhaps too small to mix it up with outside receivers or too slow to engage in trail speed battles with downfield burners, this cornerback was a substitution player at best, and an expendable chip at worst. Now, the typical nickel corner is a pure starter and is treated as such. And this player has a unique skillset.
Matt Bowen, who played safety in the NFL from 2000 through '06 and now writes brilliantly about Xs and Os for Bleacher Report, told me flat-out that in the modern NFL, the slot defender might be the most important defensive back on the field. In 2005, when he played with the Washington Redskins, Bowen was part of defensive packages that defensive coordinator Gregg Williams called "Ruby," in which there were three defensive linemen, two linebackers and six defensive backs. Williams used the late Sean Taylor as the point man in the defense -- the multi-position safety/corner hybrid -- because Taylor had such freakish athletic ability and field sense. Now, players like New Orleans' Kenny Vaccaro and Arizona's Tyrann Mathieu carry on that legacy in different ways. And as Bowen said, there's so much to that position; you're ideally taking equally from cornerback and safety skillsets and basically creating a new archetype
"To play nickel now? I think it's really hard. You have to play the two-way go [option routes in which the receiver can turn inside or outside based on coverage] inside the numbers, you have to be able to tackle, and you have to be able to blitz. And blitz is a technique, just like playing man-to-man or running routes. You need practice at that. You can't run in there straight up and down like a pencil, or you'll get decapitated. Because as the nickel, sometimes you blitz, and the tackle is set up on you. How do you beat him? You've got to get him back on his heels -- you set him up, almost like a basketball player driving to the hole.
"All that stuff takes practice. It takes reps. So, those new nickels in today's NFL? They're football players. They have to do everything. It's not just, 'OK, we've got a small DB; let's put him in the slot and we can hide him there.' No, no. I think the nickel right now, in terms of the secondary -- he may be the most important position on the field. In my opinion, if you don't have a [good] nickel [defender], you can't win."
Harris, who has played in the league since 2011 and has been Denver's slot weapon since Day 1, has said that his position provides new reads for quarterbacks to grasp, adding to his positional value.
“I know just from talking to Peyton [Manning], when he’s trying to figure out a defense he looks right at me to tell him exactly what type we’re in," Harris said. "So I’m constantly moving around, showing Peyton different looks, showing him that I’m blitzing and then dropping back in coverage. So since I know that he’s always watching me and trying to figure it out, that’s a huge position. Nickel is definitely a huge position which a lot of quarterbacks are looking at to find what type of defense we’re in. Pretty much, that’s all we run. That’s pretty much our main defense, really.”
), but defensive coordinator Dan Quinn said that he and the team's coaching and scouting groups value those attributes more than ever. Even when you have a once-in-a-generation secondary, you never know when the fifth guy will come in handy.
"There's special coaching that goes into that player," Quinn said. "He plays near the line of scrimmage, he's got run fit techniques that he has to do, so he's a really valuable guy. And he has to have special quickness to play inside, because so many of the guys who play in the slot have that quickness, where maybe a taller, longer guy doesn't have that kind of matchup stuff. He's unique, so when we're evaluating players, we'll say, 'OK -- he's a corner who can play nickel.' And when you're looking for guys who can add versatility, it's nice."
One is the Loneliest Number: Covering from the slot
Remember what Bowen said about the nickel defender setting up tackles like a basketball player would? Well, that basketball metaphor also works when talking about coverage. Nickel defenders have to cover tight ends more and more often thanks to super-athletes like Jimmy Graham and Vernon Davis who are basically power forwards with receiver's hands. These days, though, it's not just tight ends and slot receivers those defenders have to deal with. Offensive coordinators looking for an edge are putting their top receivers in the slot more often than ever.
In 2013, according to Pro Football Focus, the Chicago Bears put Brandon Marshall in the slot 43.8 percent of the time -- 266 out of 608 routes. The Green Bay Packers put Jordy Nelson in the slot 52.1 percent of the time (he was a nightmare for opposing defenses there) and the Arizona Cardinals had Larry Fitzgerald in the slot on 289 of his 599 total routes (48.2 percent). As Greg Cosell of NFL Films told me last year, there are specific reasons for this new wave of mega-slot guys -- offensive coordinators want to see just how on the ball these new defenses are. And it all comes back to skillset.
"It becomes difficult to match up, because a lot of cornerbacks are purely outside corners -- they don't play in the slot," Cosell said. "They're not comfortable playing two-way gos, and you get those in the slot. A lot of cornerbacks grow up playing outside. If they're playing man, they're comfortable with the sideline as a defender, basically. They know that they can play that way, and they're comfortable with certain techniques that you can only play on the outside. There are a lot of good corners who just are not comfortable playing inside.
"Let's say you're playing man-free coverage -- if you're doing that [in the slot], you have no help to the outside. There's a lot more room to defend, and it's just harder."
"It's nothing to flex the tight end out, or flip the receiver and the tight end, so the tight end is in the slot. That [slot defender] is unique, and he's got to be able to play on a number [slot receivers]. There are man-to-man techniques on bigger and smaller players. We train a number of players at that spot, because we know how important it is. You need depth there, just like you need depth at the other positions."
Depth in the secondary can be quite a valuable commodity. The Pittsburgh Steelers played dime coverage (six defensive backs) on an amazing 45 percent of their snaps in 2013, and there were times, especially in their playoff loss to the Colts, when the Kansas City Chiefs used dime as their base defense.
Bowen estimated that depending on the gameplan, the Redskins under Williams would use "Ruby" and other kinds of extra-DB base concepts 30 percent of the time at the very most. Last year, the Bengals led the league with five or more defensive backs on the field 74 percent of the time. Former Cincinnati Bengals defensive coordinator Mike Zimmer took the head coaching position for the Minnesota Vikings in the 2014 offseason -- the Vikings ran nickel or more 68 percent of the time in 2013, ranking second in the league. They acquired former Panthers cornerback Captain Munnerlyn in the offseason, and guess what Munnerlyn will be doing a lot in 2014?
"It doesn’t matter where I play as long as I’m on the field making plays," he said in March, soon after the Vikings signed him to a three-year deal. "I’m the starter at cornerback and slide into the nickel when [opposing offenses] come out in 11 personnel and when they have three receivers in the game, so I’m excited about my role. I’m excited about my role and I’m ready to step up even more and just show some of the young guys how to be a pro. I had to learn from somebody, and now it’s my time to be a teacher."
The Chicago Bears selected Brock Vereen out of Minnesota to serve a similar purpose -- though he'll play safety, he showed in college that he could roam all over the field.
"That’s why we worked so hard to get in position to draft a safety in Brock Vereen, a player that has played multiple positions in the back end of the defense, in terms of playing outside, in the nickel slot and at safety," Bears general manager Phil Emery said after the pick was made. "We see him as a safety. We feel that will be his best pro position. He certainly has the physical tools for it, in terms of the athletic upside. He certainly has the mind for it, in terms of his football and his instincts. And he certainly has the toughness for it. He’s got good experience under his belt. He’s been a productive player and we’re looking forward to his contributions at safety."
Kick Out the Jams: The NFL's best slot defenders
In 2013, Richard Sherman led the league with eight interceptions. He put that number up on 547 snaps and 57 targets. Impressive, to be sure, but what about the season put together by Eagles slot cornerback Brandon Boykin? On 353 snaps and 75 slot targets, Boykin picked off six passes and allowed an opponent quarterback rating of 57.8. Chris Crocker of the Bengals was the only slot guy to allow a lower passer rating (48.2), and he thrived in Mike Zimmer's schemes in Cincinnati. He'll do the same in Minnesota, as the Vikings signed him on Aug. 4. The aforementioned Chris Harris has been one of the most underrated defenders in the league for a while now -- in the slot last season, he picked off three passes and allowed no touchdowns on 393 snaps and 56 targets. Walter Thurmond played very well when the Seahawks went to nickel last year, and the Giants signed him in the offseason to expand and enhance their own multi-dimensional concepts -- Big Blue runs as much three-safety stuff as anyone in the NFL.
Where is this all going? Will the NFL eventually honor slot defenders as All-Pros and Pro Bowlers? Will these players find themselves selected in the first half of the first round of a draft? Will they ever get the big money that the best outside guys do? That's to be seen over time, but one thing's for sure -- NFL defenses have been critically altered in the last few years, and that plug nickel is worth far more than ever before.