The Logics of Man Marking: Digging Deeper into Marcelo Bielsa’s Defensive System

All Stats Aren’t We
13 min readDec 10, 2020

The other day, I was sent a question from a Twitter DM that includes some of the brightest young minds in football analysis. Despite being a Manchester United fan, Kees van Hemmen has an eye for tactical subtlety: “Anybody read anything good on man marking and how it interplays with aggressive pressing structures and positional play? Been meaning to find something about Leeds/Atalanta that talks about the actual why of them doing it, not just the how.”

A few months ago, I had written about “the how” of Leeds’ defensive system in a piece entitled “The Principles of Leeds United’s Defensive System under Marcelo Bielsa: A Primer”. But despite reading, listening or watching everything I could get my hands on about Marcelo Bielsa’s approach to football, I had never come across anything which explains “the why,” as Kees calls it.

In the absence of anyone more qualified to talk about this subject writing about it, then (and after conversations with far more qualified people than myself on the topic), I thought I would turn my mind to the question of “the why” of man-marking in Marcelo Bielsa’s football system.

A Pragmatic Idealism

When it comes to Marcelo Bielsa, there is a received wisdom which pits him as an incurable idealist, ignoring any evidence to the contrary and stubbornly persisting with his approach even when it seems fruitless. In this instance, though, as is so often the case, the received wisdom is more “received” rather than “wisdom”. There is actually a curious pragmatism to Bielsa’s idealism.

When he was interviewed by El Grafico in 1998, Bielsa’s father, Raphael, made the claim ‘I never saw Marcelo play nor have I seen him manage. It’s not that I don’t like football, it’s because I am a Central supporter and also because I prefer another type of football, one which has less marking and pressing. We talk about it every time he comes home. He has his point of view and he tells me that he has to train his teams to win.’

In this context, Bielsa senior is picking up on two aspects of his son’s football style in particular — the pressing and the man marking — as aspects that he doesn’t like. Bielsa junior, however, justifies the decision to play in this way because of a desire to win.

There is a tendency within modern football to label “negative” football “pragmatic” and “positive” football “idealistic”. Questions should be raised about the use of the labels “positive” and “negative” of what are more often than not, aesthetic judgements. But in the case of Marcelo Bielsa, despite his outspokenness on football being primarily entertainment, he is just as pragmatic as that arch-pragmatist himself: Jose Mourinho. Where they differ is over the kind of football that will be more likely to get you over the winning line.

That said, there is a level of almost arbitrariness to Bielsa’s idealism too. There are times when he has spoken about his tactical system with a shrug and the suggestion that “well, you have to pick one system and this is the one I went for”. This gives his idealism a strange quality — almost a zealotry — which seems, as zealotry so often does, to conceal some sort of inherent insecurity about the idea itself. It’s almost as if there is nothing to suggest the certainty of the idea beyond his holding of it.

Brought together — the idealism and the arbitrariness — and contextualised by the quote from his father, Bielsa’s ideas about football are united by a holism. Yes, it may be the case that the basic system is arbitrary — not intrinsically better than another system in terms of its effectiveness — but there is an internal coherence. Bielsa wants to win playing this kind of football and so any decision that stems from an original arbitrary decision to play “this football not that football” must be made in such a way as to improve the chances of winning.

Bielsa’s System

With the more abstruse elements of Bielsa’s approach to football out of the way, let’s clarify the more concrete aspects. The Argentine is committed to two broad aspects when it comes to a tactical system: on the ball, he approaches the game through a “positional” logic; and off the ball, he approaches the game using a man-marking system.

I consider the aggressive press as straddling both of these aspects. On the one hand, the aggressive press is necessary for a team playing high possession football with players in advanced positions because it buys time for the team to fall into a defensive structure. For Bielsa, that defensive structure is a man-marking structure and so the aggressive press works in such a way as to allow Bielsa’s team time to find their marking responsibility in the event of a turnover.

Returning to Kees’ original question, the nub of the matter is whether there is an inherent relationship between these two aspects: does Bielsa apply a man-marking system because he sees it benefitting the positional approach he has adopted in on-the-ball phases? If so, what is that benefit?

Let’s not forget at this point that Pep Guardiola adopts a positional system in possession but a zonal structure out of possession. If there is a correlation between the in- and out-of-possession phases of the game, then we might be able to suggest one or the other changes their defensive system to benefit their positional approach.

Let’s begin by clarifying the two aspects:

Positional Play

For something that sounds so ominous, positional play is fairly straightforward as a concept (although it gets complicated in practice). It simply indicates any on-ball system that looks to use player movement to generate an attacking edge.

The buzzword that is often thrown around here is “superiorities”. That simply means situations where a team has an overload — where their players outnumber their opponent’s in an area. Positional play is all about fashioning these overloads all over the field in a bid to create dangerous attacking moments.

You could call this spatial manipulation but it’s not just about space. It’s about making sure the players and the ball arrive at the right place at the right time. We’ll go into this more in a bit.


As I’ve already set out in “The Principles of Leeds United’s Defensive System under Marcelo Bielsa: A Primer”, Marcelo Bielsa looks to set his team up man-for-man in out of ball phases.

However, there is a caveat. He applies a +1 Rule in defence and a -1 Rule in attack. Giving the striker the responsibility for pressing two strikers means that he can have a “spare man” — what he calls a “libero” — in defence to help out wherever there is trouble.

Within this general man-marking system, Bielsa implements what he calls a “partial libero” principle. That means that a player is able to leave their marking responsibility when they judge a more dangerous situation to have arisen elsewhere. This is where the spare man comes in. He is supposed to cover any opponent who is left over after any defensive reshuffles.

A Series of Queries

With all the basics in place, we can finally turn to address the issue at hand. In terms of advancing ideas about why Bielsa might prefer a man-marking system to marry up to his positional play system, there isn’t really any scope for an evidential approach at this point. I suspect there won’t be until some form of functional tracking data becomes widely available.

As a result, I want to present a series of queries — thought experiments — to offer some suggestions as to why Bielsa might prefer man-marking as a defensive system. If any of these are plausible at all, then they might offer at least the starting point for some sort of proper investigation at a later date.

Query #1 — Structural Benefits

On the face of it, if there were a benefit from using a man-marking defensive system alongside a positional approach, it would seem likely to come from some sort of structural “fit” that would allow easier transition between attacking and defensive setup.

For Leeds, the most basic attacking shape they look to get into is this:

Given the flexibility of the positional system, the positions given aren’t hard and fast: the winger can underlap, for example, or the central midfielder. The basic approach is this: try to get the ball possessed in a wide area where you can fashion an overload on the ball-near side and get your players attacking the five spaces between the players in a back four (or six spaces in a back three/five).

From this position, the question is whether anything is gained by dropping back onto opponents rather than dropping into space? A few things need to be clarified:

Firstly, it seems unlikely that a man-marking system reduces the amount of running that a team have to do. As this graphic from SkillCorner shows, Leeds United are comfortably the most dynamic team in the Premier League at the moment (not to mention Europe):

Although Manchester City come a close second behind them when it comes to team sprint distances, it seems unlikely that Leeds man-marking system reduces the ground they have to cover in order to get back into a defensive shape. This would indicate that there isn’t a structural benefit to man-marking.

Query #2 — Practical Benefits

Obviously, defensive transition isn’t simply about getting back into defensive structure as quickly as possible. It’s as much about getting back into a functional structure as quickly as possible. Could it be the case that because man-marking systems aren’t aiming for an ideal structure — a 4–4–2 or 4–5–1 setup, for instance — that they actually become more efficient in transition?

Again, it’s impossible to offer anything by way of concrete evidence here. Anecdotally, though, this quote from Kalvin Phillips is instructive:

Of course, Phillips is a defensive midfielder and so the defensive structure is a fundamental aspect of his role. But the final few lines are interesting: ‘“Keep track of your own player and you’ll be in a good way.” I keep that thought in my head.’

No doubt in a zone-oriented defensive system, the players keep the zone that they are responsible for in their head but there is a difference here: the individual is responsible for keeping track of their opposition player. Their spatial relation to their opponent is constantly changing and so is constantly at the forefront of their mind.

Perhaps this carries little to no ramification at all. But it seems as though there could be a potential benefit to marking an individual rather than a space in terms of the practical utility of such an approach.

Query #3 — Benefits of Simplicity

In putting this question to my good friend Nico Morales, he suggested there could be a simplicity factor at play here. His thinking is this: it’s known that Marcelo Bielsa focuses on repetition and pre-rehearsed movements in possession which famously require a huge amount of time and effort to bring into fruition. The man-marking system, Nico proposes, is probably the more simple system to coach compared to a more zonal approach and will therefore leave more time to focus on the possession phase of the game.

On the face of it, this might appear unconvincing: the man-marking system seems fairly complex when it comes down to it. But the beauty of a man-oriented system is that it is entirely commensurable week on week. The structure is decided by the opponent and the only real tweaks will occur in the forward areas where the -1 inferiority can lead to some issues.

Zonally, it’s an entirely different ball game. You will probably be using some sort of complex combination of high press, mid-block or low block, you might have different systems for different periods of the game and you might have to change up your pressing triggers depending on the specific scenario in-game.

For Leeds, this is never really an issue. You’ll be marking your player. You may have to switch which player you mark from time to time. You have to think on your feet and make decisions as a “partial libero” but that will be the same in every game you play.

Query #4 — The Uniqueness Benefits

There is probably one final potential benefit from the man-marking system adopted by Bielsa. It could be the case that he likes the fact that playing against Leeds is relatively unusual within elite football. Except for Gian Piero Gasperini at Atalanta, there are very few coaches who use a man-orientated system out of possession. As a result, there are a lot of quotes from players and managers who have played against a Bielsa team and who have been overwhelmed by the uniqueness of it all.

Of course, there are managers who claim that Bielsa teams are “easy to figure out”. There is a truth to this — there are few managers who are so logical that you can pre-empt them with the sort of success that you can with Bielsa. He’s on record laying out the formations he uses to counter other formations. This should come as no surprise. With his man-marking systems and the basic principles of +1 in defence/-1 in attack, you can guess the structure from the structure of the opposition.

The point is that the reality of playing against the man-marking system is much more difficult than the theory behind it. For players who have spent their entire careers playing in zonal systems, it shouldn’t be too surprising that a week of preparation isn’t enough to ready them for the experience.

Query #5 — The Attacking Benefits

So far, we’ve focused the discussion on the defensive transition element of the interplay between positional play and man marking: the movement from on-ball to off-ball. Could there be any benefit the other way around? Could moving from a man-marking system actually benefit positional play?

I think this is potentially the most difficult question to answer in this subject area. On face value, I would want to argue that the opposite is true: that a man-marking system will mean that any counter-attack will begin from a position in which the team in attacking transition are already close to opposition players.

On top of this, you have the added negative that your players have to drop in the defensive phase. You can’t keep your front three advanced because if the opposition full backs are advanced, then your wingers need to drop deeper.

That said, it seems logical that a man-marking system will mean there is always space in behind the player who is being marked. In attacking transition, Leeds always seem to be able to find space despite starting off close to their men in the defensive phase.

Perhaps it is the case, then, that the man-marking system does lend itself to attacking transition insofar as being close to your man at the beginning of a transition ensures that you can attack the space immediately behind your opponent.

Maybe a better way of expressing this concept would be to say that, coming up against a man-marking system means that you are almost forced to play a man-marking system in defensive transition because that is the structure your opponent is using at the moment of turnover. If you’re man-to-man and lose the ball and track back, you will largely stay man-to-man.

Whether or not this lends itself to any attacking benefit for the man-marking team, I don’t know. I’ll leave that to smarter tactical minds than my own to explain. I do think, though, that there is a germ of an idea there to be explored.

Query #6 — The Pressing Benefits

One of the aspects that has been left largely ignored here is the pressing element of Bielsa’s approach. In some senses, this is logical because the pressing aspect is not unique to the man-marking system but common to all high possession approaches, as we discussed earlier.

But there is the possibility that rather than the interplay between positional play and man-marking it is the interplay between pressing and man-marking that draws Marcelo Bielsa to it. In both cases, the press is used to buy time for the rest of the team to fall into a defensive structure. But does an aggressive press complement a man-marking rather than a zone-oriented defensive approach?

This is probably the strongest line of attack in attempting to come to an answer to the question at hand for this reason: an aggressive press works against a transition towards a zonal structure but doesn’t necessarily have to work against a man marking system.

The basic principle would be this: in pressing, you are moving towards the ball and therefore towards a player. That overlaps with the tenets of a man-oriented system rather than a zone-oriented one. As a result, by pressing aggressively in a man-marking approach, you should be aiding the defensive structure rather than detracting from it.


I began this article with a question about the interplay between aggressive pressing structures, a man-marking system and positional play. As I was careful to stress, I have not attempted to give a definitive answer to the question because, unfortunately, it is almost impossible to apply any sort of empirical evidence to the inquiry.

However, I hope this article helps to move the conversation along that Kees van Hemmen prompted. The topic is an important one and deserves further scrutiny. And no doubt more statistically-inclined individuals might be able to take these ideas and fashion them into hypotheses that can then be furnished with data and made to look more or less plausible.

Thanks should go to Tiago Estêvão and Nathan Clark who helped me to clarify a lot of these ideas in my mind as I was writing this piece.

You can follow Jon Mackenzie on Twitter @Jon_Mackenzie.

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All Stats Aren’t We

A Leeds United blog which focuses on the tactical and statistical aspects of the game