Brendan Rodgers chose to play three at the back but it was only when he switched to 4-4-1-1 that his side came to life
Whereas previous Chelsea coaches have been tactically flexible, Roberto Di Matteo's strategy has remained constant in recent weeks.
It is the same for the majority of big matches: a 4-2-3-1 with Eden Hazard, Oscar and Juan Mata behind Fernando Torres. Therefore the key tactical decision rests with the opposition manager. Arsène Wenger had to choose between the pace of Gervinho or the height of Olivier Giroud, for example, and Sir Alex Ferguson picked a 4-4-1-1 rather than a diamond in midfield for last month's 3-2 win at Stamford Bridge recently.
Brendan Rodgers tried something entirely different: a back three, which he had used in the midweek defeat by Anzhi Makhachkala and more pertinently, considering the sizeable rotation for the trip to Russia, in the second half of the Merseyside derby a fortnight ago. Maybe the former Chelsea coach had also noted how his old side struggled against an opposition back three when Juventus snatched a 2-2 draw at Stamford Bridge in September; Chelsea led through two Oscar goals from long range but their wide players were forced back by the Italian team's wing-backs and had little impact.
The same happened here. Rather than playing near Torres and pressing the Liverpool back three, Mata and Hazard dropped close to the midfield and allowed Daniel Agger and Andre Wisdom time on the ball. As a result Liverpool recorded the highest possession figure – 57% – for an away side at Stamford Bridge since February 2010, but the passing was slow, with little penetration. They stifled Chelsea's creativity but also harmed their own.
Rodgers is obsessed with possession but Liverpool had too much of it before the interval, allowing Chelsea time to get men behind the ball. The away side did not offer incision – even after Rodgers tilted his midfield trio midway through the first half, pushing Nuri Sahin higher up to join Steven Gerrard, rather than sitting alongside Joe Allen.
With three centre-backs able to defend the penalty box, Liverpool might have been better off playing on the counterattack – Ryan Bertrand and César Azpilicueta would have been free to attack but the prospect of Luis Suárez and Raheem Sterling roaming into the channels before sprinting in behind would have worried the centre-backs. Instead, with the Chelsea full-backs in place and the midfield providing protection, Liverpool completed twice as many passes as Chelsea in the first half but failed to test Petr Cech; the formation offered false dominance rather than outright superiority.
Rodgers made just one substitution. After an hour he introduced Suso in place of Sahin, told the Spaniard to play just behind Suárez and switched to a 4-4-1-1 formation. Glen Johnson moved to left-back, with José Enrique and Sterling on the flanks. Now Liverpool offered greater forward passing options, an extra threat in the penalty area and more width high up the pitch, stretching the Chelsea defence. As with Terry's opener, Liverpool's equaliser came from a set piece in a game featuring little creativity but it was a fair reflection of their increased ambition after the formation change.
Liverpool also had the finest chance at 1-1, when Cech became a sweeper to thwart Suárez outside the box. That type of move, with the Uruguayan breaking past the defensive line, was the type of situation Liverpool should have been striving for in the first half.
For the first time, Roberto Mancini's back three looked useful in the 2-1 victory over Tottenham. Previously, the formation had only worked when either Mancini's side or the opposition had been reduced to ten men – in the FA Cup tie against Manchester United in January, for example, or in the Community Shield win over Chelsea.
Yesterday, the formation made sense on paper. Tottenham were using two forwards – Emmanuel Adebayor with support from Clint Dempsey – and those two were tracked by the three City centre-backs. This allowed Maicon and Aleksander Kolarov to push forward from wing-back, allowing David Silva into a permanent central position, from where he played a sublime chipped pass to unwilling yet prolific supersub Edin Dzeko for the winner.
There was more to City's victory than the formation change – they already had the momentum even with a back four, while Tottenham played a surprisingly high line and tired significantly towards the end of the game. Still, the back three made sense, and it worked on the pitch.
Morgan Schneiderlin grabbed the opener in Southampton's 1-1 draw with Swansea on Saturday, but the Frenchman is also doing an excellent job in the centre of midfield – he's completed 43 tackles and 35 interceptions so far this campaign, and therefore has won possession more often than any other Premier League player.
He is forced into an all-action role because of the attack-mined nature of the rest of Southampton's midfield, but on Saturday Nigel Adkins gave Jack Cork, a battling midfielder, his first league start of the season in the centre of the pitch, and this seemed to bring more structure and discipline to the side.
Adkins will have to cope without Schneiderlin soon, however – he picked up his fourth booking of the season on Saturday, and will incur a suspension after his next caution.
Michael Cox is the editor of zonalmarking.net