Data Rant: pressing

Aside from an obsession with possession the mainstay of Louis van Gaal’s philosophy has been an insistence on a high line. Curiously, however, the heavy pressing that usually accompanies adventurous defensive positioning has been noticeably absent at Old Trafford.

This is in contrast to many of United’s rivals for Champions League football. Leicester, Tottenham Hotspur and Liverpool have each committed more fouls and tackles than Manchester United. The number of tackles and fouls is usually a good barometer of pressing, given that truly defensive-minded teams sit back rather than defend proactively. In the possession-neutral context (Table 1, below) United’s lack of pressure is particularly startling.

[wptg_comparison_table id=”2″]
All relative to other teams in the Premier League

There is a reason a high line is matched tactically with intense pressing. Without a defensive contribution upfield, the defence is badly exposed in the case of a turnover of possession. Risk-taking in the attacking third becomes, relatively, more dangerous and the team has to collectively step backwards in the defensive phase. This in turn saps tempo upon regaining possession. This is a malaise familiar to all at Old Trafford.

In United’s last two games against Chelsea and Swansea City Van Gaal deployed Ander Herrera, the Reds’ most mobile and diligent midfielder,  at number 10 to add more bite in the attacking third – at the expense of Wayne Rooney against Chelsea and forcing Anthony Martial to the left against Swansea.

But is the high line/pressing combination worth all the fuss? After all, United does not really have a Ji-Sung Park-type forward in the squad. Meanwhile, Rooney’s fitness continues to deteriorate and his defensive contribution has been lacking this season. For example, Rooney averages just 1.6 tackles per game compared to Juan Mata’s 2.8. It is fair to say that Van Gaal simply doesn’t have the squad to execute on his ideal philosophy.

Shots-per-game – a good indicator of overall attacking prowess – has demonstrated a weak relationship with pressing this season (Figure 1, below). It is worth recalling that Sir Alex Ferguson’s late-noughties side dominated the Premier League and reached the Champions League final three times without any particular insistence on high line or pressing. Further, pressing is almost completely unrelated to points won this season (Figure 2, below).

[visualizer id=”197706″]
R2 = 0.12455

[visualizer id=”197707″]
R2 = 0.01186

This analysis plays out historically too. Arsenal, a club which has traditionally emphasised pressing to facilitate a high line under Arsene Wenger, has not won the Premier League since 2002. If anything, Arsenal’s run for the title this season can be attributed to Wenger’s abandonment of his strict adherence to a high line.

This, of course, does not mean that a heavy pressing side can never win trophies – Pep Guardiola’s Barcelona is a famous counter-example. It is just that United is simply not putting in the defensive work in advanced areas that is required to make the high line work.

One solution is for Van Gaal to shape his team into a ‘proper’ pressing side. However, the data proves it is unnecessary – a team that does not press can also be successful. Since United is not pressing heavily to begin with, defending a little deeper could open up other options – ones that are more attacking and pleasing to the eye.

United’s 2-1 victory against Swansea may have earned Van Gaal some time, but he needs to either fully, truly, commit to his philosophy or admit defeat and bravely explore new avenues. The alternative may be an unceremonious end to a distinguished career.

That Van Gaal has failed to put together a coherent strategy, despite a being afforded a season and a half at Old Trafford, is plainly evident. More than that, it is now doubtful whether the Dutchman had a coherent philosophy to begin with. Should Van Gaal fail to accept and work with the reality he faces it is likely to prove fatal for the veteran manager.

Assumptions dictating linear regression have not been held strict.
Data from whoscored.com and squawka.com