Chelsea overcome their six game slump with a hard-fought but ultimately deserved 1-0 victory against Bolton, who would have gone ahead of Chelsea into 5th place in the Premier League had they emerged from Stamford Bridge with a win. Although the media will focus on Chelsea's confidence and swagger re-emerging after Florent Malouda's 61st minute goal, there are also some interesting tactical points of the game that have gone more or less unremarked upon. The midfield in particular was a point of considerable interest - for the first time during the slump Chelsea made a significant change of shape, moving away from the 4-1-2-3 that they'd been using for the vast majority of the season.
On Monday, Carlo Ancelotti had made a puzzling substitution to start the second half against Arsenal, removing John Obi Mikel and replacing him with £18M man Ramires, a move generally assumed to get more linkup between the defence and the midfielders. This backfired in a fairly major way - the defence was weakened substantially, and the midfielders appeared thoroughly confused about where they were supposed to be, and as a result Chelsea conceded two goals early and spent the rest of the game chasing what appeared to be an insurmountable Arsenal lead. Assuming Chelsea had been committed to playing a 4-1-2-3, the substitution made less than zero sense.
Instead of starting Mikel against Bolton, Ancelotti didn't even include him in the squad. Ramires started alongside Michael Essien and Frank Lampard in a central midfield three - but not in Chelsea's usual inverted triangle. Instead, the Ramires-Essien duo was used as a holding double pivot, leaving Lampard as a roaming central attacking midfielder. With two holding players, Chelsea had relatively few problems with containing Stuart Holden and Fabrice Muamba in Bolton's centre, and both Essien and Ramires were able to make surging runs forward without exposing the back line.
Unfortunately for Chelsea, they were the only outlets from defence in the first half, since the fullbacks were remarkably sloppy in their attempts to play the ball forward. Neither Ashley Cole nor Jose Bosingwa were able to feed the wide forwards, which led Nicolas Anelka and Florent Malouda dropping back to try to pick up possession in deeper positions. Chelsea's shape in the first half, then, looked suspiciously like a standard 4-2-3-1, with Didier Drogba roaming around ineffectually as a lone striker and the team trying to punt long balls forward to him, bypassing the one area where they had superiority - the midfield.
The 4-2-3-1 appeared to be mostly accidental, and Chelsea's major change at half time was pushing the fullbacks and wide players much higher up the pitch to shift back into a 4-2-1-3, essentially mimicking Arsenal's typical shape. This move had a variety of knock-on effects, but the most important was forcing the Bolton back line into dealing with multiple threats rather than just contain Drogba. As a result, the play was significantly more stretch, which enabled the midfielders more space to start attacks. Lampard's play significantly improved after the restart, and it was a through ball from him which led to Drogba hitting the post in the 48th minute, and Malouda's goal was mostly the result of Essien being able to charge straight through the centre of the pitch. Although dropping Mikel in favour of Ramires seemed like a bizarre thing to do, it ultimately strengthened the midfield enough for Chelsea to use their new shape as a platform from which to change the game.