4-2-3-1 has been the popular formation in the Premier League the last few seasons but one that Brendan Rodgers did not use during his side's surprising second place finish last season. Rodgers has stated he prefers 4-3-3 with a single holding midfielder and two runners over 4-2-3-1 because it allows for more vertical passing options. He's stated that in 4-2-3-1 the two holding midfielders can often end up playing too many harmless side to side passes to one another. You can hear Rodgers explain in the video below.
One of the big pluses with 4-2-3-1 of course is that two deep lying holders provide better cover for the back four than one. When Liverpool played 4-3-3 or a diamond 4-4-2 last season, Steven Gerrard operated as the lone holder. Gerrard is a fantastic player but isn't always positionally disciplined and at 34 isn't as mobile as he once was. As a result, Liverpool's defense was often left too exposed. They scored a remarkable 101 goals but conceded 50, 13 more than the Manchester City side that would beat them to the title and 23 more than Chelsea. Their capitulation at Selhurst Park after going 3-0 up in the penultimate game of the season, a game that would end 3-3 and all but give City the title, summed up Liverpool's biggest problem in an otherwise great season- they were incredibly fluid and could score with ease but struggled to change their approach and tighten things up when circumstances dictated they should do so.
Perhaps as a result of his side's openness last season, Rodgers opted for a 4-2-3-1 today with Lucas and Gerrard holding in front of the back four. Liverpool were certainly more solid and compact defensively. They did not get as stretched on the counter and Southampton didn't create much the opening 45 minutes. However, they also offered far less penetrative passing than we saw last season. When Liverpool play 4-3-3 (or 4-1-4-1 if you prefer) and Gerrard gets the ball in deep areas he generally has 4 midfielders in front of him to play forward passes into- the two shuttling center midfielders, Coutinho and Allan likely candidates, and the two wide midfielders (Figure 2). As a result Liverpool play more vertically, get forward more quickly and have more players in the attacking third. In the 4-2-3-1, Lucas sits alongside Gerrard, leaving him with only 3 midfielders higher up the pitch to play forward passes into- the #10 (Coutinho today) and the two wide midfielders (Sterling and Henderson today). When the opposition defends in banks of four as Southampton did today, having three attacking midfielders in advance of Gerrard rather than the four we see in a 4-3-3 makes it easier to defend- Southampton's midfield bank of 4 has a 4 v. 3 advantage in the midfield zone (Figure 1). As a result, Liverpool played a lot of sideways passes between the holding midfielders and center backs and struggled to funnel the ball into the attacking third at pace.
After Southampton equalized, Rodgers switched to his more attacking 4-3-3 shape replacing Lucas with Joe Allen. Although the shape gives Liverpool more attacking thrust, immediately we saw some of the same defensive problems Liverpool were faced with when they played that formation last season. Gerrard was left to shield the back four on his own and almost immediately Liverpool conceded possession with Gerrard out of position towards the left wing. With no one patrolling the center of the park for Liverpool, James Ward-Prowse got the ball in acres of space in the middle of the pitch and was able to drive uncontested at the Liverpool center backs. The 19 year old Southampton midfielder made the wrong choice in trying to shoot from 25 yards out with better passing options on either side of him but a more experienced side will punish Rodgers' side for allowing themselves to become that open.
Rodgers then replaced Coutinho with Rickie Lambert and moved to 4-4-2. With Allen higher up the pitch than Gerrard Liverpool were even more open and Southampton continued to threaten. Liverpool got the winner however, more as a result of some good fortune and hesitant Southampton defending then Rodgers' tactical changes. Lambert appeared to handle the ball on the sideline in the build up to Liverpool's goal then Southampton failed to deal with the second ball after Clyne initially headed clear a Henderson cross. Sterling nodded Clyne's header towards an unmarked Sturridge at the back post for a tap in.
Incredibly, with his side continuing to look stretched defensively in midfield, Rodgers elected not to use his third sub to bring on a third central midfielder for Sturridge or Sterling. Emre Can seemed like the obvious choice. Instead Sterling, Sturridge and Lambert all stayed high up the pitch and Liverpool defended with a midfield three of Gerrard, Allen and Henderson. Southampton continued to be dangerous and Liverpool were fortunate to escape with the three points. Morgan Schneiderlin rattled the crossbar for Southampton and Shane Long missed an open net with a follow up header.
Rodgers is an excellent manager, adept at changing systems while still getting his sides to play fluid, coherent football. However, his decisions today seemed strange. At home against a side gutted by players departing on summer transfers, you'd have thought he'd be a bit more adventurous with his team selection and gone with a 4-3-3 from the outset. Yet when the circumstances of the match dictated he should make cautious changes, he did not.