Pressing is nothing new in football. It's introduction can be traced all the way back to the mid-1960s, when Russian coach Viktor Maslov instructed his Dynamo Kiev players to apply intense pressure on their opponents in order to win back possession. A similar tactic used by legendary Austrian manager Ernst Happel, whose Feyenoord side pressed their way to the European Cup in 1970; which of the two men was first to make the innovation is debated to this day.
Later, Rinus Michels, with Ajax and Holland, formed his ‘Total Football' blueprint with aggressive, co-ordinated pressing at its core, while Valeriy Lobanovskyi constructed three great Dynamo sides, across a 29-year period, who all put intense pressure on the ball.
With its roots in ice hockey and basketball, the importance and prevalence of pressing in modern football has grown with time. Now, the majority of the foremost contemporary coaches espouse a system based around pressing.
Branching off into different schools of thought, the more innovative tacticians coming up with a multitude of ways to implement the tactic, setting traps for the opposition and pinpointing the optimum part of the field in which to recover the ball in order to launch an immediate attack.
Over the last couple of years, pressing has become a hot topic in the Premier League. Jürgen Klopp has brought his gegenpressing methods over from the Bundesliga, Mauricio Pochettino's high press has been poured over and copied, and Pep Guardiola's ‘six second rule', which dictates his players must press the opposition for six seconds after losing the ball before falling back into their defensive shape, is a well-known tenet of the Catalan's philosophy.
But which of the Premier League's press masters do it best? And which sides are behind the curve when it comes to recovering the ball by applying co-ordianted pressure?
As ever, the statistics are illuminating. By looking at each team's passes allowed per defensive action in the opposition half (PPDA), courtesy of understat.com, we can see which sides pressure their opponents soonest.
The PPDA statistic measures, on average, how many passes an opponent makes before said team is able to disrupt their possession with a defensive action, such as a tackle or interception; in a broad sense, the fewer passes allowed before a defensive action is taken, the more effective a side's pressing is.
While many consider Klopp to be the master of pressing in the Premier League right now, his Liverpool side actually only rank fifth in this measure at the moment with 10.37 PPDA.
It's evidence, perhaps, of how the Reds have de-emphasised the aggressiveness of their pressing recently in favour of a slightly more possession-oriented approach – in 2015/15, Liverpool ranked fifth for average possession (55 per cent), while they were second only to Manchester City last season (58.3 per cent) and are averaging a fourth-ranked 56.5 per cent this term.
However, as their recent victory over City proved, Liverpool still very much have the option of pressing their opponents into submission if they choose to use it. But Guardiola's men are so comfortable on the ball and so effective in playing out from the back that, even though Liverpool's intense pressing was effective, the Anfield club still averaged only 13.5 PPDA against the league leaders.
City top the chart when it comes to PPDA, evidencing the effectiveness of Guardiola's six-second press. Liverpool do, however, appear to remain an extremely efficient gegenpressing, counter-pressing, unit, leading the league with eight counter-attack goals (three more than second-ranked Tottenham Hotspur) while figuring highly in the PPDA stats.
City, on the other hand, have scored only twice on the counter this season. Guardiola's prefers a more considered approach to constructing attacks, demanding a spell of rapid ball circulation though midfield to unbalance the opposition before exploiting gaps in their structure.
Spurs come closest to City when it comes to PPDA, with an average of 7.7, then comes Arsenal (8.45) and, somewhat surprisingly, Southampton (8.93).
Of the established ‘big six' clubs, Manchester United and Chelsea have the most relaxed approach to pressing. José Mourinho often opts for low defensive block in key encounters, allowing the opposition to have the ball in their own half before applying pressure as they approach goal, contributing to a PPDA of 10.56.
The Blues' 11.67 PPDA is pretty consistent with their average of 11.08 from their title-winning campaign last season, showing that pressing in the opposition's half is not the only route to success.
To no one's great surprise, City are the side most effective at playing through pressure. The average PPDA of their opponents this term us a whopping 23.04; Liverpool (18.03) rank second and Arsenal (15.11) third.
With City dominating the pressing and possession stats while sauntering towards the Premier League title, Guardiola's men are showing they can mix style with substance, aesthetics with sheer graft.