Back in November after Spurs first began experimenting more regularly with three at the back, manager Mauricio Pochettino made a point in one of his press conferences that a change in formation does not necessarily mean a change in system.

Sounding somewhat annoyed by the line of questioning, Pochettino said, “We played with different formations last season against - I don't want to be repetitive - Watford. And against Arsenal at the Emirates and against West Ham. Against Monaco we played with four at the back again. Maybe they're different formations from the beginning but at the end the same philosophy and the same principles.”

This is the key point for understanding how Pochettino’s 3-4-3 actually works and why we can use the formation regularly: It’s not actually that different from how we played all of last season.

Formations in themselves are not that important in the big picture.

Before we talk about Poche’s 3-4-3, we need to make a note up front about how formations actually work in soccer. Though I don’t see it as much as I once did, there is still sometimes an idea amongst soccer fans that a change in formation by definition means a change in system.

Another way of stating the same idea is that fans often act as if formations and systems are the same thing. Thus a 4-4-2 is assumed to always be different than a 4-3-3 or a 4-2-3-1 or even a 3-4-3. But the actual differences between these formations can vary a great deal depending on many different factors.

Indeed, the differences between two teams that play the same formation can vary a tremendous amount. Tim Sherwood and Diego Simeone both frequently use the 4-4-2 but no one would ever confuse Sherwood’s drunk yelling YOLO 4-4-2 with the disciplined, physical 4-4-2 Simeone uses.

So, to take Spurs as an example, many fans have suggested that Pochettino has changed his approach this year relative to last year’s. In some fairly superficial ways that might be true.

To be sure, he has varied his formations more this year than at any other point in his career. And to the extent that it has taken him time to figure out how to get this team playing the way he wants them to, it’s fair to say he has “changed” this season.

That said, what’s striking about the 3-4-3 that he seems to have landed on is that it looks a lot like the 4-2-3-1 of last season in several key ways. We’ll break them down below.

Both the 3-4-3 and last year’s 4-2-3-1 keep three defenders in deep positions and use those three defenders in similar ways.

I won’t spend too much time on the point about splitting the center backs because we already have covered that. But this might be a helpful way of talking about how the center backs work in both last year’s 4-2-3-1 and this year’s 3-4-3: Think of the typical three man midfield. It can be a 4-3-3 or a 4-4-2 diamond; it doesn’t really matter.

In many teams that use a midfield three, though not all, the roles played by the there players are something like this: The two outside players in the trio are box-to-box midfielders who are expected to get up and down the field vertically, assisting as needed on the defensive side but also making late support runs into the box in the attack. The central player in the trio is responsible to stay deeper, recycle possession from a deep central position, and sweep up whatever messes get left behind by the more aggressive outside runners.

The roles of the back three in Pochettino’s system actually look a lot like that, but for defenders. The outside defenders are what we might call line-to-line center backs, meaning they work in the channels on either side of the center back in the space between the goal line and halfway line.

Last season, Toby Alderweireld and Jan Vertonghen played in these wider center half roles whenever Eric Dier, ostensibly a defensive midfielder in the 4-2-3-1, dropped off into a deeper central position. This is something the team did from the very first match of the season. Note where Dier and Alderweireld are receiving the ball even in the first game against Manchester United, which came before the emergence of Dele Alli or the decision to partner Dier with Mousa Dembele in midfield.

Dier:

He’s not receiving a ton of passes, but of the ones he is receiving, a considerable portion are in the part of the field where you more common expect to find a center back than a defensive midfielder.

Now Alderweireld:

The vast majority of the passes Toby received even in his first ever league game for Spurs are received in spaces where you expect to find a right-sided center back in a back three or even a right back rather than the right-sided center back in a back two.

The difference in the number of passes the two players receive hints at another important point. The reason that Pochettino uses his center backs in this way is that they are instrumental in his attacking strategy. I have linked to this piece multiple times, but it tells the story well: Spurs were the only team in the top six last season whose most common passing combinations all involved defenders and who relied on direct attacks to create more than 25% of our shots.

The passes attempted chart for Toby from the same fixture against Man United last season illustrates this point nicely:

Interestingly, one of the changes we have seen in the past six weeks is that Pochettino now seems to favor Alderweireld in the deep central role and Dier in the right-sided role. But the responsibilities seem to basically be the same. The above is from Alderweireld, the right-sided center back in last season’s 4-2-3-1. Below we have Dier’s passes attempted against Chelsea last week:

Obviously he is playing fewer passes than Alderweireld did in that weird opening fixture last season, but the types of passes he’s making and the places where he is making them from are quite similar.

What our right-sided center back needs to do is find room in the defensive half-spaces (the space between where wide players and more central players will typically play) to receive the ball and pick out more aggressive, ambitious passes. This holds true whether Spurs are playing the more conventional 4-2-3-1 we saw for most of last season or the 3-4-3 we have seen more regularly in recent weeks.

This role is vital for the Tottenham attack because one of the things that comes from having a fairly defensive manager like Pochettino is that our front six generally does not include an elite passing midfielder, like Modric or even an Ander Herrera-type playmaker, and so that passing has to come from somewhere else. For Pochettino, it usually comes from the center backs.

Both the 3-4-3 and last year’s 4-2-3-1 use similar strategies in the attacking third.

A second point of similarity between the 4-2-3-1 of last season and this year’s 3-4-3 is that both systems use the advanced attackers in similar ways. Tottenham tends to be an extremely narrow team in the attack for a few different reasons.

The first point is that the commitment to the high press dictates how the team sets up. To press effectively, teams need to be compact. If players are spread out across the field, it is impossible to press well because pressing well requires that multiple players attack the ball in order to both apply pressure to the man in possession and to cut off the passing lanes that would give the man in possession ways to get rid of the ball. One or two players cannot do that.

As a result, pressing teams have to keep a compact shape so that they always have enough players near the ball in order to press when the pressing trigger is activated.

The second thing driving player position in Pochettino’s system is that though Pochettino teams typically have high possession numbers, the system is not meant to produce high amounts of sustained, long-term possession. Rather, the system is designed to attack directly, turn the ball over, win the ball back quickly, attack directly, turn the ball over, repeat.

Interestingly, the top four possession teams in England right now reflect these different approaches to possession. The first and fourth teams on the list, Manchester City and Arsenal, want sustained possession that allows them to control the tempo, wear the opposition down, and probe the defense for weaknesses. The second and third teams on the list, Liverpool and Spurs, want a high number of short bursts of possession ending with quickly taken shots. (Recall that City and Arsenal produce the highest quality chances in the EPL while Liverpool and Spurs lead the league in shots attempted.)

Whether it is the 3-4-3 or last year’s 4-2-3-1, this narrow positioning (and the underlying philosophy that explain the narrow shape) is present. The Chelsea fixture is actually a good example of this. Christian Eriksen routinely played almost more like a right inside forward, operating in the attacking half space as an advanced creator much like David Silva has done for City over the years. This role was virtually identical to the role he plays in the 4-2-3-1.

Likewise, Dele Alli took an advanced central position that often turned him into a de facto second striker as he made vertical support runs off of Kane that led to both of the Tottenham goals. This is the same sort of role he played in last year’s 4-2-3-1.

That said, we should note at this point that the 3-4-3 does add a wrinkle that the 4-2-3-1 generally does not. In last season’s 4-2-3-1, we had four defenders plus Dier as a sort of defender-midfield hybrid, Dembele as a central midfielder, and then four attacking players. The 3-4-3 complicates that picture.

In games where we start Dembele and Wanyama in midfield, we end up sacrificing one of last year’s attacking four for Wanyama. The trio of Alderweireld, Vertonghen, and Dier play in similar ways (with Dier and Alderweireld seeming to have swapped roles, admittedly) but Wanyama and Dembele are then used to provide additional muscle in midfield ahead of the back three.

However, in most of the games where we have used the 3-4-3 this season, we have functionally ended up with something that is almost more 3-3-3-1:

Lloris

Dier, Alderweireld, Vertonghen

Walker, Wanyama, Rose

Eriksen, Alli, Son/Sissoko

Kane

Theoretically we’re still playing 3-4-3 only with Eriksen partnering Wanyama rather than Dembele. But Eriksen is a very different sort of player than Moose and so he ends up as less an orthodox central midfielder and more an odd kind of central midfield/attacking midfield hybrid. I suspect that we’ll see something very like this when Erik Lamela returns from injury.

This, then, is perhaps one of the most encouraging things about the 3-4-3: It allows us to stay in the same basic system, but it not only maximizes Wanyama’s abilities, it also allows us to rest Dembele without breaking our midfield in the way we did whenever Dembele rested last season. (That Pochettino was able to find a tactical solution to the Moose-needs-a-break problem speaks to his creativity as a manager.)

Both the 3-4-3 and last year’s 4-2-3-1 use the fullbacks in similar ways.

Finally, we’ll end on a brief note about the fullbacks. The obvious downside to playing as narrowly as Spurs routinely do in the attacking third is that this can make your attack quite easy to defend. And there have been a number of matches this season where our attack has looked quite stagnant due to too much sustained possession in the attacking third and not enough of the knowledge or ability needed to break down bunkered-in defenses. (Hey guys, we’re playing West Brom on Saturday!)

The way Pochettino fixes this problem is obvious, of course: He pushes his fullbacks far up the pitch. Indeed, even last year in the 4-2-3-1 both Danny Rose and Kyle Walker routinely played more like wingbacks than fullbacks, providing the primary attacking width for the team. That has continued this season.

The risk to playing wingbacks, of course, is that they leave space in behind them that clever opponents can exploit. Tottenham’s fix for that problem last season was dropping Dier off and pushing Vertonghen and Alderweireld wide to deal with those wide attacks from the opposition.

We still see a lot of that this season. But there is an additional patch for that problem with this year’s team: Victor Wanyama. Though he is a significant liability in the attacking phases of play, Wanyama is a fantastic destroyer who covers a tremendous amount of ground. And as Chelsea have shown with N’Golo Kante in their own 3-4-3, if you have an industrious destroyer in midfield who can cover a lot of lateral ground, that can further help deal with the risks of pushing your fullbacks so far forward.

Conclusion

The success of Pochettino’s 3-4-3 is not that it is an entirely new way for Spurs to play. Rather, it is a way of playing that is wholly consistent with Pochettino’s general philosophy that also adds a few additional layers of complexity and nuance to the system. Put another way, 3-4-3 allows us to do all the things that 4-2-3-1 did last year, but it also introduces variation into the system by allowing us to play more of a de facto 3-3-3-1, it gives us a solution that actually works quite well when Dembele is not available, and it maximizes Wanyama’s abilities as a midfield destroyer.

This won’t be a popular comparison, but one of the things Brendan Rodgers did very well at Liverpool is that he was able to think creatively about how to maximize the talent he had in his squad. This is how he ended up playing a diamond midfield for much of the final Suarez season and how he hit on his own version of the 3-4-3 to mask some glaring deficiencies in his team for much of the year after Suarez left.

Unfortunately for Rodgers, his own ego and the often enormous amounts of time he required to figure out the best system (and the bad results he frequently got while figuring it out) meant that he was not a good long-term solution for Liverpool despite some real strengths he had as a manager. Pochettino reminds me a bit of Rodgers in that he has been able to creatively tinker with his squad in order to get the most he can out of his players while staying true to a general attacking system.

That said, because Pochettino is a far better manager than Rodgers, he has been able to figure out a good system a bit faster than Rodgers could and the results Spurs got while Poche was finding that system have been far superior to Liverpool’s results during Rodgers figuring-it-out phase.

This, then, is another reason that Poche is an ideal manager for a club like Spurs: Though he has his weaknesses, the things he does well are perfectly matched to the things that a club like Tottenham need from their manager.