Arsenal man-marking defence
Arsenal played with Emery’s commanded man-marking approach and structured their defensive shape around Chelsea’s active region. This prompted the away team to fore-press Chelsea whenever the ball played by Chelsea’s backline causing the later to pass sideways to counter the press. But Chelsea’s backline amazingly exploited this fore-pressing from the opponents in their build-up by pulling the opponent players closer to them to create space behind these closing-up defenders in the midfield so as to play a forward pass, or a threaded pass, instead of passing back to the goalkeeper.
However, it’s not just Chelsea’s ability to quickly capitalise these spaces but also lack of coordination by Arsenal’s man-marking approach, due to which the away defence couldn’t stop the unexpected forward runs by Chelsea players. Pedro’s goal is one of the examples before which Willian’s inside cut also pulled Bellerin along-with leaving space for Alonso at the flank to make his run and pass to Pedro already running from his respective flank levelling up with the defence. In the second half though Torreira replaced in for Xhaka to improve the defensive stability of Arsenal at the midfield. Same goes for Morata’s goal following Azpilicueta’s long pass which could be attributed to away defenders’ lack of defensive judgement in a man-marking setting.
In short, Arsenal’s uncoordinated man-marking approach caused their defensive structure to position itself as a whole following the attacking regions dictated by Chelsea. But within their defensive structure, there was a lack of communication among the players which was exploited by Chelsea’s players making runs from behind.
Chelsea played as a coherent unit
Sarri has implemented a cohesive playing structure for his team both on and off the ball. As already exhibited in their first league match at Huddersfield, Chelsea played a highly attacking football with the forward plays started as far as from the backline. Chelsea players are inclined to maintain this possession and passing game by structuring coherently close to each other to ensure multiple passing options around the ball-carrier. On the other hand, when off the ball this close coherent unit enables Chelsea defence to remain compact.
The passing structures in the central regions were set up to have three passing options around the ball carrier with Jorginho at the base of it. Barkley and Kante often went up alternatively depending on when the play commenced from their respective plane while Jorginho remained at the base of the passing play.
On the other hand, the passing structures in the wider planes had four passing options with the respective centre back at the base of the passing structure, the respective central midfielder at the front, and Jorginho at the inside to shift the play horizontally if needed. The Blues have already been famous for their diamond passing sometime back; now the same is being implemented in Sarri’s intense, offensive style.
Jorginho at the inside of Chelsea’s diamond-shaped passing.
The coherent display compressed the play and so the positions of the players on the pitch to an extent that it opened up the flanks for Chelsea’s fullbacks as the wingers were cutting in. While Willian and Barkley had more of their influence towards the inside, their replacements, Kovacic (first appearance for Chelsea) and Hazard, tactically gained Chelsea by shifting the influence to the width. This also worked well in response to Arsenal’s replacement of Torreira to stabilise the defence.
Chelsea’s defensive arrangement in goal area
Chelsea did defend like a cohesive unit, however, the defensive organisation was still likely to lose compactness once the opponents penetrated to Chelsea’s defensive third via long balls or via any quick pick-and-pass play while in the transitional phase. As a result, Chelsea coped up with this loosening of compactness by going all flat. Following this, the midfielders also dropped back to go flat with the backline. This left a huge space for the opponents in front of the defence line to take long shots. Instead, the midfielders should have remained ahead of the backline to stop such long shots.
As the play, on the whole, was compressed enough to leave one of the flanks open, Arsenal also exploited the open wings to penetrate to their final third, like Chelsea did to Arsenal. And once penetrated, they were good in sending crosses from the wider planes into the spaces left by Chelsea outside or between their passing structures.
This vulnerable defensive arrangement of Chelsea also conceded them expected goals (xG) stats which increased dramatically for Arsenal in the second half surpassing that of Chelsea’s.