After months of tearing teams apart at the Etihad Stadium, Manchester City lost their second game of the season on home soil on Monday night. Both times – to Bayern Munich in the Champions League and to Chelsea – they were beaten by a better side but also one that exploited the flaws of City's 4-4-2 system.
That formation is why they have been so good this season, scoring 115 goals in all competitions, but it also contains weaknesses, as seen on Monday. Of course, the system is not wholly independent of the players and, with Fernandinho and Sergio Aguero in the team instead of Martin Demichelis and Edin Dzeko, City might have been able to risk it against Chelsea. But without them they certainly could not.
Silva stifled by lack of space
David Silva is the league's best exploiter of space in between the lines of defence and midfield, and last week he cut Tottenham apart, revelling in their lack of a holding player.
On Monday night, though, Chelsea had two – David Luiz and Nemanja Matic – sat in front of their centre-backs, blocking the middle of the pitch. They were strong and disciplined enough to deny Silva space, leaving the little Spaniard to go either too wide or too deep. City had possession, but only ever on Chelsea's terms.
Demichelis easily picked off
The problem with 4-4-2 is the lack of protection the midfield can offer the defence, and with no Fernandinho in the centre the City rearguard was even more vulnerable.
Jose Mourinho played a 4-2-3-1 with Willian in the middle, and he and Eden Hazard targeted Demichelis, who was far too immobile for the role he was asked to fulfil.
With Yaya Touré stranded up field, and not much help from the other attackers, Demichelis was left isolated – and Chelsea could easily break straight through.
Ivanovic invited to attack
Mourinho praised City's full-backs before the game, but it was Branislav Ivanovic who won the match. With Silva, City's nominal left winger, providing very little defensive cover, it was too easy for Ivanovic to rampage forward, in tandem with Ramires. So Chelsea's right-back was free and unmarked to score the winner and often provided a wide option.
Cesar Azpilicueta, on the other side, could not attack as much given the attentions of Jesus Navas, but he did not need to.
Will Messi mean a rethink?
Twice now City have been picked apart at the Etihad by intelligent opposition – first Bayern and now Chelsea.
They have two weeks until the arrival of Barcelona who, in their heyday, were some of the best ever manipulators of space. The Catalans still have Lionel Messi, Andres Iniesta and of course Neymar, who will try to exploit those gaps City insist on leaving.
The big question for City manager Manuel Pellegrini is whether he will stick with that approach on 18 February or compromise.