By Kelvin YapFollow @@plevyakin
The match shaped up to be a battle between two similarly narrow 4-2-3-1 sides, which ended up producing a cagey match where mistakes, rather than creative opportunities, decided the outcome.
Arsene Wenger went with the mobility of Gervinho rather than Olivier Giroud's presence up front and made the decision to drop Mertesacker to make way for returning captain Thomas Vermaelen, which was logical given Chelsea's perceived lack of aerial threat after Didier Drogba's departure.
Roberto Di Matteo retained the same narrow side which struggled to score against Stoke last week, looking to create space down the middle by the rotating movements between Oscar, Eden Hazard and Juan Mata. Defensively, Job Obi Mikel and Ramires were tasked to patrol the area in front of the back four and prevent runs cutting in front of the box which Cazorla and Alex Oxlade-Chamberlain favoured, forcing Arsenal wide to cross in the ball for the tall Chelsea center backs to clear.
Arsenal's width came from their full backs, who were encouraged to overlap into the final third, while Chelsea's full backs held back, which resulted in Arsenal having more width despite having ostensibly ‘narrower' players.
In the middle of the pitch, both sides were evenly matched and man-marked, cancelling each other out. This set up a congested midfield for a cagey tie, which then led to a slow-transitioning style that clogged up play.
Because of that, it was always more likely that, as mentioned above, a mistake or a set piece would decide the result.
The right way for both sides
Both sides chose to focus their play down the right flank, but for rather different reasons - Chelsea chose to attack Arsenal's weaker flank while the Gunners simply lacked the personnel to draw wide on the left flank, given Podolski's tendency to cut in between Ramires and Luiz instead of pulling down the wide line.
For Arsenal, Ramsey was helped by Carl Jenkinson, who has improved over the off-season into a mature full back capable of overlapping the attack. The early injury to Abou Diaby also brought on Alex Oxlade-Chamberlain, who was a natural winger and stuck to his wide role down the right.
When Manchester City played Arsenal last week, they chose to focus their attack down the left flank, presuming that the less-experienced Jenkinson was the weaker full back in the Gunners' back line, but the youngster was up to the task and coped with the attack. City later changed their emphasis down the other flank and had an easier time up against Gibbs, who had the tendency to lunge in and commit the tackle earlier.
It was apparent in the match, where Jenkinson shone with intelligent movement in both defence and attack while Gibbs was less sure of his movements - Chelsea realised this and set Ramires on bursting runs into the Arsenal half to help shift the play down their right.
Credits roll for Oscar
Oscar also drifted towards the right when attacking, simply because he was assigned to man-mark Arsenal's playmaker Mikel Arteta, but it had an unexpected benefit as well.
The young Brazilian showed the defensive side of his game with an excellent man-marking performance on Arteta, frequently forcing the Spaniard deep into this own half.
It tells in the statistics, where Arteta had only 16 passes received half an hour into the match. It may seem impressive, but he had 42 passes received by the same time against Manchester City the week before.
Koscielny not the only one to blame
Since Chelsea's focus was down the right, it then isn't surprising that both of Chelsea's goals came from this area.
While Koscielny appeared to be the villain for conceding the two goals, it's harsh to pinpoint him as the sole reason for the loss -in fact, both goals conceded had something far more common than meets the eye.
Both free kicks were conceded in the same area of the pitch from needless challenges by Vermaelen, which speaks of Arteta being less able to cope with Chelsea's interplay, whereas someone else like Abou Diaby might have performed better defensively. This isn't to blame Arteta, but to give credit to Chelsea for forcing the play down the correct area of the pitch.
Also, it can be put down to rustiness on Vermaelen's part, given his return from injury. Either way, both free kicks should not have been conceded and the other Arsenal players should shoulder the blame as well as they failed to defend as a unit.
Arsenal's creation problem
The Gunners were always going down the right flank but found little result in it, because 1) Cazorla was given very time due to Ramires' tight marking and 2) Aaron Ramsey was poor.
This highlighted Arsenal's problem in creating chances and it's clear that they are starting to have an over-reliance on Cazorla to funnel their play into the final third. In fact, the Spaniard has created or scored all of Arsenal's goals with the exception of their 6-1 win over Southampton.
Against Chelsea, Ramires did an excellent job tracking Cazorla and it was the perfect time for other Arsenal players to step up against the inconsistent Mikel. Well, Ramsey did and managed to make Mikel look good (although Mikel did play a very tidy match by holding the midfield, credit to him).
It was a rather insipid tie tactics-wise, with both managers doing little to change their shape until late in the game when Victor Moses came on.
The result was one that Chelsea deserved simply because they forced the mistakes out of Arsenal with what I feel is their first showing of tactical organisation this campaign.
I admit that I have slagged off Chelsea at the start of the season, criticising Di Matteo's lack of tactical shape (which was apparent when they were outplayed by Wigan earlier this season), but this performance has made me eat humble pie while admiring their handiwork.
They were impressive in the way they started defending from the top, with Oscar and Torres especially hardworking in chasing the ball down, which is surely a happy sign for their owner Roman Abramovich, who has made known before his desire to play ‘Barcelona football'.
As for Arsenal, it's clear that someone must help Cazorla in terms of making things happen in the final third. Ramsey's poor showing did little but to make Arsenal fans look forward to Jack Wilshere's return.
They have now conceded three set piece goals in a week, a poignant point given the praise sung about assistant coach Steve Bould's influence in shoring up their defence after clean sheets in the first two matches of the season.
However, it should be taken into consideration that goalkeepers are supposed to take charge during set pieces and it's clear from the second goal conceded that Vito Mannone lacked the assertiveness to take charge, which means that Wojchiech Szczesny's return should signal better times for the Gunners in terms of set pieces.
*Formation graphics are from www.sportsdood.com's 'Football Dood' app on Android
Kelvin will be analysing a Premier League match every Monday in Tactics Watch. You can reach him by following his twitter account @plevyakin for more tactical insights and football updates.