A dominant and clinical first half performance by Arsenal practically ends the game before the break, while Chelsea tryout a new system in the second half.









Chelsea buildup problems

Unlike Chelsea's previous opponents this season, Arsenal were able to cause problems to Chelsea's, usually stable, short building from goal kicks. In particular, they were able to pressure Chelsea high and prevent Willian from dribbling through pressure upon receiving the ball from the backline. They started their press by having Ozil and Sanchez both in between the spaces of the two central defenders and Kante. Here Sanchez would initiate the press to Cahill, and Ozil would be positioned inside to prevent Kante being a passing option. Sanchez would also use his pressure from the inside, blocking the pass across to Luiz. They would have two different options to pressure Ivanovic: Iwobi or Coquelin. The former would move up as Monreal marked Willian tightly, while Coquelin and Cazorla would move across to support the central areas--to be there to pressure Willian if he tries to make his trademark dribble inside, to pick up Cesc if he is in these areas to receive the ball, and to block the possibility of long ground passes up to Costa on the backline. When Coquelin moved up to pressure Ivanovic, Iwobi would hold a deeper position to prevent Ivanovic passing the ball up the wing, while Willian would be forced to move inside earlier to receive the ball. Here Willian would continue to be followed by Monreal, while Cazorla was there there in closer support. Koscielny would also situationally mark options like Costa or Cesc from these situations.



The whole midfield moved over to pressure these situations, while the progression through Willian has been a consistently successful outlet for Chelsea this season. The preventing of this option was a major problem for Chelsea, as it created situations where their weakest passers during building had the ball most often. From these situations they would lose the ball, either through poor passes or hitting the ball long while under pressure--especially upon passes back to Courtois. As a result, Arsenal could win many second balls and collect the ball in high positions to maintain a high field position.









Later in the half Chelsea were able to finds ways through the Arsenal pressure and create some dangerous situations in the final 3rd. However, both a mixture of good defensive numbers in the Arsenal block and poor decisions lead to Chelsea not being able to convert any of these opportunities to get back into the game.





Narrow wingers find spaces between lines

With the ball Arsenal made good decisions, where they would always seek to play with the ball in the Chelsea half. They would play long goal kicks with the team moving up the field to compete for the second ball to begin. Next, when Chelsea would push up from their midfield block, and Arsenal had the ball in their own half, they were calm and always chose the right option--even under intense pressure from Costa. They would pass back to Cech, push up as a team, and play long passes into the Chelsea half.



This was a good strategy for this game, as Arsenal were able to retain the ball in the Chelsea half, while Chelsea struggle to maintain good control when defending in deep areas. The poor defensive control by Chelsea in these situations is due to a few factors. Firstly, their central midfielders play in a very individual way defensively. The three of them all move up out of their zone to press individually, while they are unable to gain closer collective positions around the ball and options around the ball. The lack of collective forward pressing from these situations opens up possibilities to use the vacated space behind the wide Chelsea midfielders. Here Arsenal were excellent. They used Ozil, Coquelin, Cazorla (and Sanchez situationally) outside in deeper areas to circulate the ball patiently to draw the three Chelsea midfielders out. Both of their fullbacks were high and stretching the Chelsea backline, while the narrow Wingers were able to make good use of the vacated wide space in front of the back 4. The second goal was a result of Iwobi and Walcott making good use of these spaces, while the high positioning of the fullbacks (Bellerin in this situation) was able to create a 2v1 against Azpilicueta.





































































The high position of the ball possession and the deep Chelsea block meant that when Chelsea won the ball, Costa was isolated and under intense pressure from the Arsenal backline. Costa was able to hold the ball extremely well on a few occasions during these situations, but Arsenal were able to cut off the majority of counterattack threats through their pressing to win the ball high, while retreating to a deep defensive block when Costa was able to hold onto the ball and find support.

Another area where Arsenal excelled was counterattacks. They were able to attack quickly and play short combinations to progress up the field, as well as using the speed their players posses. From deeper positions Bellerin was an outlet to carry the ball up the field quickly, while Ozil, Cazorla, Iwobi and Sanchez were able to find combinations to bypass the Chelsea midfield centrally. As they reached the final 3rd, they had the added option of the runs Walcott makes behind the Chelsea defence. Cech also had a very quick reaction to try to play long and counter quickly when he had the ball, however his long distribution was inconsistent throughout the match.





Chelsea switch to a 343

In the second half Conte switched the system with the introduction of Alonso for Cesc. This had a positive impact on the Chelsea buildup, where Arsenal were no long able to pressure them high--giving Chelsea the first moments of a stable buildup in the game. From these positions there were able to use the wide central defenders to play forward passes into the narrow front three. The narrow roles of Willian and Hazard provided some much-needed central support to Costa, as well as more forward passing options into central areas.





Both wingbacks covered the full line, moving up onto the last line with the ball, as well as dropping back to the Chelsea backline when they lost the ball. When in high areas, they would receive long passes from the central midfielders, before combining or crossing the ball into the box.





Similarly to the first half, Chelsea still had problems during counter attacks. One change with this system, however, was that they would have the 3 central defenders in positions to get back into the box--opposed to two central defenders facing counter attacks alone towards the end of the first half.









In reaction to Chelsea’s change in system, Arsenal dropped to maintain a collective block. As one problem for Chelsea was solved (achieving a stable build up) a new problem occurred as a consequence: trying to breakdown the deep Arsenal block.

Usually Chelsea don’t attack deep collective blocks, as they hold the ball in deep areas and provoke the opposition to play high--before playing passes through the stretched lines and bypassing the first lines of pressure. Against the deep and organised block they were able to maintain a high field position, create situations to dribble and combine with the ball centrally, and cross the ball into the box through the fullbacks. The lack of strong players in the air, the numbers Arsenal had in the box to successfully clear the ball, and a lack of a first post attacker (until the introduction of Batshuayi), prevented Chelsea having good success through these crossing situations--while the central dribbling wasn’t able to create chances inside the box.

Conclusion

Strategically and excellent first and second half from Arsenal. They were able to prevent Chelsea having the same amount of success that they usually have had during their buildup, while also preventing Chelsea from controlling the rhythm of the game. Clinical finishing and solid defence allowed for a good result for them. Chelsea, on the other hand, need to find a way of not conceding (at least) two goals in the first half of every game.