The tactical fluidity that makes PSG so impressive

Aside from the centre-backs who remain in their positions, these anchoring positions can be taken up by players moving into these spaces.

Image caption,

In yellow, you see the five areas of the pitch PSG look to occupy at all times. In this example, the striker position is occupied by one of the midfielders pushing up as striker Ousmane Dembele has dropped into a midfield position.

For example, left-winger Khvicha Kvaratskhelia might start in the left-wing position before moving infield resulting in left-back Nuno Mendes filling that position. The key however is that - that area is anchored by a player.

These rotating movements can be described as zone replacements. PSG have specific areas that they need filling according to the coach. When a player leaves that area, another player rotates into that position or "replaces that zone". This helps keep the side balanced. Although they appear spontaneous, there is a level of coordination and predictability to them.

Image caption,

Khvicha Kvaratskhelia moves centrally. Nuno Mendes replaces that zone by moving from a back-three position to now playing on the left flank. The shape of the side remains balanced.

The floating players by comparison are the players who find themselves in the middle of the pitch - not bound by the positional instructions of the anchors.

These players have more license to roam freely, often combining with one-touch passing in close proximity. Naturally, defending against technical players with no true position is a task most teams struggle with.

Image caption,

The anchoring players are seen in white with the floating players given more freedom in yellow. Note striker Dembele on the ball in midfield.

How PSG players know where to rotate

When on the ball, PSG's two centre-backs are often joined by a third player to form a back three.

If the right-winger moves inside, the right-back, Hakimi, fills the space out wide. If the winger stays wide, Hakimi attacks more centrally. From this central position, he is able to pick up the ball in midfield or push further up as an extra attacker.

Mendes, the left full-back with equally as much license to attack, has a different reference point. He is asked to form part of the back three in build-up. If however the defensive midfielder - often Vitinha - drops into the backline, Mendes now has license to push up.

At this stage, his point of reference is now the winger. If the winger has moved inside, Mendes moves to the flank as somebody has to fill this space. If the winger is out wide, Mendes can now play in a free role centrally.

Based on these steps, different players end up centrally with true freedom so it can look like every player is able to move where they please. In actuality, the PSG players are going through the instructions in their head as they decide where to move.

Image caption,

Vitinha (yellow) is in a defensive midfield position. This means Nuno Mendes forms part of the back three while winger Kvaratskhelia stays out wide (white). Hakimi stays out wide on the right because his winger is positioned centrally (blue).

Ballon d'Or winner Ousmane Dembele is given the most freedom of the PSG players, and rightly so. He is perhaps the only player free to move where he feels best and is frequently seen posing difficult questions of defenders by moving into positions that they are reluctant to move into.

His ability to receive on the ball, turn and drive before passing or shooting with both feet make him an invaluable player across the pitch. Reacting to his movements, PSG's nearby players, often the wingers moving inside, or the midfielders or full-backs pushing centrally, move forward - leading to goals being scored given the difficulty around tracking their runs from deep.

Image caption,

Demeble, PSG's striker on paper, leaves the attacking line. Virgil van Dijk is seen gesturing at Mac Allister to pick him up. The attacker's unusual position drags Van Dijk away from the right side of the pitch and distracts him as PSG build up to what resulted in a goal.

Is this style feasible in the Premier League?

A clear trend in world football has been the increase in man-to-man defending, something Premier League coaches Pep Guardiola and Mikel Arteta have stressed all season. With Luis Enrique's team constantly moving around the pitch, opponents tasked with following their man eventually lose their player, either unintentionally or purposefully deciding to retreat when being pulled to the other side of the pitch.

This tactic, like all tactics, is dependent on player quality - which brings us back to the first quote of this piece. In an ideal world, Enrique wants 20 players who can play in all parts of the pitch, so they could replace each other's zones without any drop off in quality.

He probably mentions 20 players rather than 11 because these tactics, including the long and intense sprints of the full-backs from their own half, to the opposition's box and back, are taxing on the mind and body.

PSG however, have the benefit of being a better team when compared with the rest of Ligue 1 which allows them to rotate frequently. This season, Nuno Mendes has played 46% of PSG's total league minutes which leaves him in good physical condition to perform Luis Enrique's demanding instructions to a high level in the knockout stage of the Champions League. This is a luxury fellow Champions League semi-finalists Arsenal - who play their first leg at Atletico Madrid on Wednesday - probably cannot afford.

Luis Enrique, however, with the players at his disposal, has conjured a brilliant mix of physicality, chemistry and technique to produce one of football's most exciting teams in recent memory.