The fastest-growing trend in the Champions League is using a hybrid defender to switch shapes on the fly.
Once upon a time, not all that long ago, each soccer team had a formation and each defender in that formation had a position. You could play in a back four with two center backs and two fullbacks, or you could play in a back five with three center backs and two wingbacks, but in either shape the central and wide defenders had pretty different job descriptions. When a former fullback like Carles Puyol or Sergio Ramos decided it was time to stop scampering up and down the wing, he simply moved into the center back pair and let somebody else take over his wide gig. There wasn’t really a third option.
Then the whole juego de posición scene blew up. Good teams decided they loved long, slow possessions, and good coaches put a lot of thought into choreographing them, including working out ways to contain counterattacks. They started getting creative at the back. The best possession teams these days practice detailed, phase-by-phase shape changes as they work their way up the field, and the best defenses respond with versatile formations of their own. Teams increasingly want two center backs at one end of the pitch and three at the other. Sometimes they switch between a back four and back five during a single phase of play, just to keep opponents on their toes.
There are different ways to pull off a variable back line, but one of the most popular right now involves tweener defenders who can play like center backs one moment and fullbacks the next. More often than not they’re veteran wide players who haven’t fully converted to a central position but have a foot in both camps. This hybrid role has gotten so popular so fast that half the Champions League is doing it and we’re barely even talking about it yet—in fact, I’m not sure anyone’s even bothered to give it a name.
Reader, meet the elbow back.
He’s this year’s least hyped but fastest-growing tactical trend: part outside center back, part fullback, all flexibility all the time. Think Kyle Walker at Manchester City, Danilo at Juventus, Nacho at Real Madrid, Mario Hermoso at Atético Madrid, Óscar Mingueza at Barcelona, César Azpilicueta at Chelsea, Marcos Acuña at Sevilla. If your favorite big club doesn’t occasionally use some version of this role, chances are they will soon. Let’s talk about why it’s a thing.
The Basic Idea Behind Elbow Backs
The easiest way to think about why you might want a shape with two center backs in some situations and three in others is to start from one of the bedrock ideas in soccer tactics, the plus-one principle. Don’t worry, this isn’t going to devolve into one of those coaching courses about sub-sub-principles. The plus-one thing is as simple as it sounds. In most situations, it’s a good idea to have more players on your back line than the other team has forwards, but not so many more that you've got redundant players just standing around. Take the number of opposing attackers and add one. That’s the efficient number of defenders.
Conveniently, this principle applies for different reasons both in and out of possession. In defense the reason is straightforward. One-on-one defending is a roll of the dice, so you want to give yourself more than one chance to keep anyone from breaking through your back line. And since forwards do all kinds of stuff on and off the ball to drag defenders out of position, you want to make sure you’ve got a guy staying home to protect the most valuable real estate on the field, in front of your goal. You want a spare defender. Of course you could crowd the middle of your defense with six or seven or ten outfield players if you felt like it, but since adding a body to the back line subtracts a body from somewhere else where he could be pressing or attacking, you don’t want too many spare defenders. Voilà: plus one.
On the ball, the plus-one principle works a little differently. You may have seen tactics Twitter drop buzzwords like “numerical superiority” and “the free man,” which are just different ways of saying you want to have more attackers than defenders in a certain part of the field so that somebody will be open. But which somebody, and which part of the field? Ideally both the guy on the ball and a teammate he’d like to pass to would be unmarked, so really an attack has two plus-one problems to solve at the same time. First, how do you get an attacker in space where he can receive the ball, face play, and have time to pick the next move? And second, how do you give him a good passing option in whatever part of the field you want to move to next? Both of these questions can matter for the shape of the back line.
But there’s another, less tactics-board-y but arguably more important reason that the elbow back role is popular right now: it just suits some guys. If there’s an a priori solution to soccer, nobody’s found it yet, which means real-world tactics are less about finding one perfect formation and more about fitting your best players on the field where they can do the things they’re good at. For a certain kind of defensive talent, those strengths may fall somewhere between the usual job descriptions of a center back and fullback. That’s okay! A wide winger can do the attacking part of a fullback’s job, and a pair of conventional center backs can handle your more physical defending in front of goal. Coaches are coming around to the idea that some players, typically experienced fullbacks, have too many valuable skills—distribution, defensive chops, tactical nous—to bench them just because they can’t body strikers in the box or sprint up and down the sideline for ninety minutes. To get the best out of these guys, they’re turning them into elbow backs.
What Elbow Backs Are Good For
To try not to make this all boring tactics theory, I’ve spent some time combing through the Champions League knockouts, looking at different ways this trend’s playing out right now at the highest level of the sport. The examples in the rest of this letter will be tied to the specific situations that seven elbow-ish backs faced in six matches. Together I think they cover most of the role’s advantages, which I’ve been thinking about in five categories:
- Shape changes in the buildup
- Rearranging a block
- Overlaps and underlaps
- Rest defense
- Reactive defense
Advantage 1: Shape Changes in the Buildup
But first, some boring tactics theory! The most common reason teams use elbow backs is to make different shapes as they move the ball up the field. Why? Well, mostly because of the plus-one principle, but you’ve already got that part. Let’s think through why it matters in the buildup.
Pop Quiz #1: What’s the point of defense? If your answer was something along the lines of “to keep the ball away from your goal,” pat yourself on the back for signing up for this blowoff class. (We also would have accepted “omfg who cares just get to the point.”) The goal is in the middle of the field, which means the fastest route to goal is up the middle of the field. Also, ball carriers in the middle of the field can move anywhere, while ball carriers on the sidelines are just trying not to dribble out of bounds and embarrass themselves in front of the ballboy. The middle is valuable. Defenses will generally let you move the ball forward a little bit if you want to go outside, and try to force you backwards if you want to come back inside.
Pop Quiz #2: What kind of passing options should you offer the guy on the ball? I’m not sure there’s a right answer to this one, but for possession teams the idea is usually “one safe outlet on either side and at least one ground pass option in the direction of goal.” You want a diamond—or as Andrea Pirlo would call it, a support rhombus. The safe outlets should be far enough away that whoever’s marking the ball carrier can’t just follow the pass and chase it down, but close enough that some other defender won’t have time to cut out the pass or close down the receiver before he can control it. By definition, a safe outlet should be at an angle the defense is willing to give you, which means forward if you’re passing to the outside of the field and backward if you’re passing to the middle.
The point of all this is that if you’re gunning for Maximum Control, i.e. a buildup that’s pretty much guaranteed to be slow and steady unless the defense really wants to risk overcommitting to the press, you’re going to need a bucket.
It’s no coincidence that so many of the top possession sides—Chelsea, Barcelona, Man City sorta, maybe Real Madrid soon, even Atlético Madrid for slightly different reasons—have switched to a back three in the last few months. Control and safety can be pretty appealing when you’ve been playing nonstop since last June and everyone’s legs feel like tubes of Gogurt left in the sun. (Might be worth noting that the handful of high-possession teams that have resisted the back three trend are almost all in the Aggressive Style and tend to have a dubious defensive record.)
But even if you decide you need a back three, you won’t always need a back three. At the start of the buildup, a goalkeeper who’s comfortable on the ball can serve as the bottom of the bucket. And if you make it safely to the attacking half, opponents will often drop into a low block and leave just one striker up by the center backs, which according to our plus-one rule means two center backs should hang back while one scoots closer to the action. Over the course of a single long buildup, the most efficient shape might go from four at the back to three to two. That’s a lot of opportunity for an elbow back to do elbow back-y things.
Because elbow backs almost all play for possession sides, their teams tend to look similar in the first stage of the buildup (two center backs split wide on either side of the keeper, elbow back in the fullback space) and the attacking set (elbow back controlling the halfspace in a 3-2-5 or 2-3-5). It’s the middle stage where you’ll see the most variety depending on the team’s tactical preferences and the opponent’s shape. But we’ll get to that in a second.
Here’s Sevilla chugging through a full cycle of possession shapes. When Marcos Acuña, the elbow back, sends the ball back to the defensive third at the start of the clip, the center backs split to the corners of the box and Acuña stays up the sideline like a left back in a back four. As play reaches the middle third, Acuña tucks in to play as a left center back in a very wide back three (so wide that there’s room for a midfielder to slip into the gaps and make it a back four again if needed, a trick Man City also loves to pull with Rodri). But when the ball gets to Acuña, the five yards between him and the sideline offer just enough room for the wingback to drop to his left and open a lane for a progressive pass straight up the middle of the diamond to Óscar Rodríguez. That kind of distribution is one of the skills that separates elbow backs from wide backs, who receive more forward passes than they play. For the final act, as Dortmund retreats into a 4-5-1 low block, Sevilla’s two center backs tend to Erling Håland while Acuña pushes up and in to collect stray clearances and circulate possession. Back four, back three, back two. A safe and efficient buildup.
Advantage 2: Rearranging a Block
Okay so yeah, like I was saying, the second stage of the buildup is where you’re most likely to see elbow back teams get creative. In the middle third there’s a natural equilibrium between a team taking it slow in possession and a defense that stops in a mid block to apply some compact pressure. The attack will drag the block from side to side with circulation and scramble it with rotations, patiently trying to open holes. Being flexible at the back can help with that.
Pirlo’s Juventus is especially adventurous with this kind of thing, thanks to Danilo’s comfort playing as a center back, fullback, or defensive midfielder. They might be a little too adventurous, to be honest—it’s not always clear players are on the same page. In the clip below, Danilo notices Adrien Rabiot lagging behind the midfield as Juve reaches the part of the field where they’d normally switch from a back four to a back three, so he jogs inside to pin Porto’s left mid, Otávio, and give Rabiot his outside center back spot. It would be a clever rotation except Federico Chiesa makes an early run over the top, leaving Rabiot no wide outlet pass on the right wing. There’s a hole in the bucket. Some quick circulation lets everyone reset, and on the second go-round Matthijs de Ligt has a nice little support rhombus to buy him some time for a diagonal out to the wing, where Chiesa’s holding in place this time. Danilo, the elbow back, has cycled through three positions in thirty seconds to help his team break through the block.
The problem with improvised shape changes is that any miscommunication or miscontrol can end in disaster, as Juve found out less than a minute into the Porto game when a rushed transition from a three-back defense to a back four buildup led to a turnover inside the six yard box and the most embarrassing goal you’ll see in Champions League play. For a crisper example of how to do this stuff, there’s no better team in the world right now than Manchester City.
A lot of the hype around the current City juggernaut has focused on João Cancelo’s role as an inside fullback, but it’s Kyle Walker on the other side who does elbow back duty. Here he starts on the right of a back three, then spreads out to the sideline so Rodri can draw out the press, and finally sprints upfield like a conventional overlapping fullback, providing width while Riyadh Mahrez comes in from the wing to receive the linebreaking pass. Clockwork.
Advantage 3: Overlaps and Underlaps
Walker’s not the only elbow back who still breaks out his old fullback tricks now and then. Positional play at the back is one way to break through a block, but you can also try to speed things up with a runner from deep, either swinging around the outside of an inverted winger like most fullbacks or shooting the channel inside a wide forward. The second approach is especially popular with teams like Real Madrid and Barcelona that play an elbow back inside a fullback-turned-wingback, allowing for easier rotations on the underlap.
Of course it also helps if your opponent likes to man-mark like Atalanta. When Nacho takes off from his left center back hole here, Ruslan Malinovskiy goes with him, scrambling Atalanta’s press. The payoff comes a few passes later, when Nacho—who’s free to stay upfield because Ferland Mendy offers natural cover at wingback—sees Vinicius Jr. occupying the left wing and cuts inside on a second underlapping run. Just twenty seconds after he was playing center back, Nacho’s laying the ball off to Karim Benzema and making striker runs in the box, leaving Atalanta in the defensive configuration known at Coverciano as “drunk conga line, wedding reception, two a.m.”
Advantage 4: Rest Defense
They may make the occasional run from deep, but elbow backs are a lot less likely than fullbacks to occupy the wing in the attack. Most of them became elbow backs in the first place because they’re too old to beat guys on the dribble or track all the way back after a run in behind. They’re better sitting deeper to pick probing passes and cut out counters before they can get to the wing. That position in the attacking set, typically about 10 or 15 yards off the opponent’s widest midfielder, is where the elbow back plays “rest defense”—literally resting and protecting space while his team tries to find a way to score.
It’s kind of cheating to sneak a clip of Mingueza against PSG in here, because he was really just a right center back in this game, a lot less elbowish than usual. And for good reason—his purpose in life here wasn’t to help Barça do fancy positional play, it was to keep Kylian Mbappé from scoring another hat trick. In the first leg, Sergiño Dest had played right back in a back four but wound up pinned deep the whole time to cope with the world’s most dangerous left winger. In the rematch, Dest, now a high wingback, was free to attack; Clement Llenglet and Frenkie de Jong doubled up Mauro Icardi in the middle; and Mingueza gorilla-glued himself to the back of Mbappé’s shirt, following everywhere he went.
It wasn’t the most restful form of rest defense, but it worked. While Barcelona’s other two center backs defended like center backs, Mingueza could go wherever he needed to cut out wide counters and keep recycling the ball back into the box, which is as good a description as any of how elbow backs operate in the attacking half.
Advantage 5: Reactive Defense
Teams that use elbow backs are not, as a rule, teams that spend a lot of time backed up against their own goal, so while there are theoretical advantages to having a guy who can defend in the box as a third center back or one-on-one on the wing like a fullback, it’s rare to see someone rotate intentionally between both jobs in a defensive set.
Unless, of course, that someone plays for Diego Simeone.
To be clear, Atlético Madrid’s back six in the first leg against Chelsea was a mistake. It had worked for Simeone to neutralize Sevilla’s wingbacks a month earlier, but against Chelsea, who are less reliant on their wingbacks, it mostly just neutralized Atleti’s attempts to get out of their own half.
Like Mingueza, Mario Hermoso didn’t do as many elbow back things in the Champions League as he usually does in La Liga, where Atleti’s default shape is an unbreakable 5-3-2. But his wide defensive rotations with Thomas Lemar against Chelsea offered hints of how an elbow back can be useful in defense. When the ball was in the middle, Hermoso man-marked Olivier Giroud, breathing down his neck every time he tried to drop off the back line. When play swung over to their side, Lemar would bump up into midfield and Hermoso would be left one-on-one with Callum Hudson-Odoi. That’s not a spot your average center back, say Stefan Savić, would be comfortable, which is probably why Simeone stacked two players outside Savić on the other side of the back line. On the left, Hermoso could get physical with a striker like a center back or square up against a slippery wingback as needed. Sounds like a job for an elbow back.
Look, I’m not saying every club’s going to start converting their over-the-hill fullbacks to elbow backs. Pulling off these positional rotations is tough, and if players don’t nail it, the risks of getting bent out of shape at the back can heavily outweigh the potential rewards. But for teams that have what it takes—the ball skills, the structured possession, the right wingback or winger outside him, and of course a guy whose talents fit the role—an elbow back can add something special in pretty much every phase of play. Fluid positioning is already a must for the best attacks. At the moment, adding some flex at the back is looking like it might be the next evolution of positional play. ❧
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