Full-back as playmaker

Saying that the role of the full-back has changed in modern football is a pretty obvious and boring observation to make at this point considering that the change started to take place in mainstream football with the emergence of Dani Alves and Marcelo over 15 years ago now.

But I think it can be argued that there has been a secondary change in recent times. Whereas the first shift was from full-backs as wide defenders to full-backs as wingers, this second shift is from full-backs as wingers to full-backs as playmakers.

And the poster child for this new wave is undoubtedly Trent Alexander-Arnold.

Although Trent might be acclaimed for his ability to cross the ball from deep (a skill associated with more traditional interpretations of the full-back role), he has plenty more strings to his bow. Between The Posts’ pass map from Liverpool’s recent Champions League game vs Genk is a good demonstration of this:

In these passmaps, players are arranged by their average position in possession; the size of the dot representing them corresponds with their number of touches (larger dot = more touches); and the thickness of the lines is proportional to the number of passes exchanged between the two players at either end of the line (thicker line = more touches).

Against Genk, Alexander-Arnold’s dot is a fucking planet compared to his team-mates who are mere moons in his orbit, and his pass lines into Gomez, Fabinho, Wijnaldum, and Salah are absolute slugs. He is the hub of his team’s passing, connecting the rest of the team to one another from his position on the right flank. That’s backed up by the column to the left of the passmap where the volume and quality of Trent’s ball progression via his passing and carrying is plain to see. Having someone in the team who can pass the ball the way he can enables Liverpool to operate without a more traditional passing playmaker in midfield which, in turn, facilitates the aggressive pressing game of Klopp’s side by allowing them to pack central areas of the pitch with more industrious players.

Another feature of Liverpool’s play that has garnered a lot of attention lately has been the cross-field diagonal passes played between Alexander-Arnold and Robertson. It helps Liverpool move the ball up the pitch quickly and aids their counter-attacking approach. The build-up to Sunday’s second goal against Man City featured a perfect example of this, with Alexander-Arnold helping his team get on the break by playing a beautiful raking pass with his weaker foot:

These sorts of passes have been a part of Klopp’s arsenal for a while now. In this clip from last season, there’s two separate Alexander-Arnold to Robertson cross-field passes that eventually result in a goal for Roberto Firmino:

It’s no mistake that these two examples come from games against Manchester City. Obviously part of that is because Liverpool vs City has been the primary rivalry in the title race over the last two seasons and their matches against each other have therefore been subject to greater scrutiny, but there’s a wider tactical point to make, too.

When a team sets up to aggressively press their opponents, they often overload one side of the pitch in order to give them numerical superiority in a certain area because that helps their attempts to win the ball back high up the pitch. By committing so many players to one side, the pressing team surrenders the opposite flank, leaving themselves vulnerable to the switch. It’s a trade-off, but one that most teams are comfortable making, safe in the knowledge that the degree of difficulty on the switch of play is so high that most players attempting it have to play a more floaty pass to ensure it reaches its destination accurately. That slower pass gives the defending team time to shuffle across and reorganise by the time the recipient gets the ball under control properly.

What makes Trent Alexander-Arnold such a threat is the pace at which he drills these cross-field passes. The ball arrows from one side to the other so rapidly that the defence doesn’t have time to reset and that gives Andy Robertson an opportunity to take advantage of the enormous amount of space the opposing team have surrendered while pressing. City have been unpicked twice by this approach in recent times because of their attempts to win the ball back higher up the pitch. Try to play on the front foot against Liverpool at your peril.

Probably the closest analogue to Alexander-Arnold is Joshua Kimmich, another player who played in midfield as a youth player and has been utilised in a central midfield role for Bayern at various points under various coaches.

Kimmich is similarly a good crosser of the ball and adept at taking set pieces too. This passmap from a game against Hoffenheim isn’t identical to Alexander-Arnold’s (partly because he’s playing with a more orthodox playmaking midfielder in Thiago) but he’s still a hub of passing and ball progression from right-back.

This type of full-back is starting to crop up elsewhere. I can’t profess to know much about Brazil under-17 football, but I saw this map from the under-17 World Cup and thought the passing of Lanza Dos Reis and Bueno Couto stood out as potentially mirroring the newer interpretations of the full-back role. They’re ones to keep an eye on in the future.

Another player to look out for is Joakim Maehle whose performance for KRC Genk against KAA Gent in the autocorrect failure derby was a sight to behold:

Look how high up the pitch his average position was! Look big his dot is! Look at the thickness of those lines! Look at his name topping all of the metrics down the left! He’s playing as a wing-back in a back 5, so the more advanced position is perhaps to be expected, but he’s practically level with his striker. At first glance Maehle seems like someone else in this string-pulling mould.

Alexander-Arnold is a bit of an anomaly in terms of his profile but it’s one that could become more popular over time, especially if the trend of aggressive collective pressing high up the pitch continues. Trent played as central midfielder at youth team level and this sort of re-purposing of CMs could be something we see more of. You can see the logic of playing young central midfielders at full-back when they break through into senior football: full-backs generally get the most touches/most time on the ball at first-team level and turning the ball over out wide is less dangerous than turning it over in the centre of the pitch so plugging in young players at left and right-back alleviates some of the pressure on them.

This could well be the dawn of the playmaking full-back era.