In 1918, the Kyiv-born artist Kazimir Malevich painted White Square, a white square on a white field. It followed Black Square and Red Square and was the culmination of his project of “suprematism”, his belief that abstraction was a means of approaching a spiritual understanding of the absolute. By that stage, he had achieved international recognition, but it left him with a problem: where to go next? When you have taken abstraction so far you are painting in white on white, what remains? And so, guided in part by the Soviet regime’s increasing hostility towards abstract art, particularly after the death of Lenin, who had been an admirer, Malevich returned to a more representational style. Some have detected a sarcasm in his later work, veiled criticism of the Soviet system, and it’s undeniable that a painting as overtly realistic as The Worker (1933) bears traces of the earlier stylisation but, still, after the floating colours and geometric shapes of 15-20 years earlier, he went back to images readily identifiable as people. Sometimes revolutions go so far that the only way forward is back. Just as we’d got used to the full-back being almost an attacking position, the very opposite of what the name implies, the fashion is to deploy central defenders at full-back. Gareth Southgate has started Ezri Konsa and Fikayo Tomori at full-back in England’s last three games. Mauricio Pochettino started the season at Chelsea with Levi Colwill at left-back. But it’s at Manchester City and Arsenal that the trend has been most pronounced, so much so that, because of the injury to Kyle Walker, there is a strong possibility that all four full-back positions at the Etihad on Sunday will be occupied by players more usually thought of as centre-backs. If only Tony Pulis were managing now. No position has undergone such profound and constant change over the past 40 years as the full-back, transformed from defenders whose job was to stop opposing wingers and very occasionally sling over a cross into often the only real source of attacking width, constantly playing on the overlap. Jack Charlton famously described full-backs as the most tactically important position on the pitch, while in 2021-22, the Liverpool full-back pairing of Trent Alexander-Arnold and Andy Robertson contributed five goals and an extraordinary 22 assists between them – they played a direct role in 29% of Liverpool’s Premier League goals that season. It made sense for both proactive and reactive reasons. As nutrition and sports science have improved, so it became possible for a player to cover the entire length of the pitch rather than being restricted to occasional bursts forward. With fewer teams fielding orthodox wingers high up the pitch there was less need to remain deep to mark. As strike pairings yielded to lone strikers and one centre-back was left as a spare man there was less requirement to act as cover when out of possession. At the same time, in possession, the lone striker meant increased space in the centre and so wide forwards began to cut infield, creating a channel for the full-back to overlap into. So why the reversion? Why have elite sides begun to look to more defensive full-backs? In part it’s because defenders have become more universal. Centre-backs are, by and large, not the lumbering heading machines of old. Ben White, Nathan Aké, Joe Gomez and Konsa may not have the goal involvements of an Alexander-Arnold or a Robertson, but equally they are perfectly comfortable in possession, perfectly capable of providing decent delivery into the box. But in part it’s perhaps reflective of a more general trend at the elite level of the game. Since 2008, average goals per game in the knockout stage of the Champions League has dipped below three on four occasions. Three of those have come in the last three seasons. Football at the highest level is becoming more defensive – something Jürgen Klopp predicted in 2019. And perhaps that’s only reasonable: after years of becoming more and more attacking, the area where competitive advantage was most readily to be found was in defending more effectively. Quite apart from the obvious point that a team with more defensively-minded players on the pitch is likely to be more defensively sound, there are perhaps two specific reasons that reinforcing cover on the outside of a back four is effective. Firstly, the rise of goalscorers from wide, which has been a growing trend for over a decade. The best way to try to combat, say, Mohamed Salah coming inside off the right onto his left foot is probably not a left-footed left-back who would prefer to be tearing forward on the overlap. From a defensive point of view, an inverted full-back or a central defender is likely to be more effective. Then there is the desire to set up to blunt an opposition counter, which often seems to mean, while still in possession, forming a defensive shape with a line of three protected by at least one and ideally two deep midfielders. That can be achieved by a central midfielder dropping between the two centre-backs, with a full-back tucking in (a trend that began with Philipp Lahm and has perhaps reached its peak with João Cancelo and Alexander-Arnold) and another midfielder dropping off, but it’s much more straightforward if only one full-back advances, leaving three defenders to shuffle across. That perhaps is what has underlain the shift at City, where Jérémy Doku stays wide on the left, meaning the channel to overlap is limited, leaving Aké or Joško Gvardiol to take up a more defensive role behind him while Walker has more licence on the right behind Bernardo Silva or Phil Foden going inside. Southgate was perhaps aiming at something similar against Belgium with Ben Chilwell driving forward to offer width as Foden drifted infield, with Konsa remaining deep to be the third defender with Stones and Lewis Dunk. This is still a very new trend and, certainly with the use of Gomez at Liverpool and Jakub Kiwior at Arsenal, there’s a sense of injuries forcing invention. But when a revolution reaches a certain point, sometimes the only thing to do is remember what the basics looked like, what was expected, before the charge to the new began.