Alexander-Arnold and Robertson: How does their defensive performance stack up against their attacking ability?

Change has very much been afoot in Liverpool’s midfield this summer with the exits of captain Jordan Henderson and mainstay No.6 Fabinho to lucrative Saudi Pro League deals weighing heavily on the departure of veteran James Milner as a free agent to Brighton.

In have come Alexis Mac Allister and attacking option Dominik Szoboszlai, while a move for Southampton’s Romeo Lavia is also in the works at Anfield.

How the change in personnel will affect Trent Alexander-Arnold and Andrew Robertson stands to be the be-all and end-all of Liverpool’s aims at securing a top-four finish in the Premier League. It was after all the shift from using Alexander-Arnold as a wing-back to a midfield role when in-possession towards the end of the last season that allowed Liverpool to build form and threaten Newcastle’s return to the Champions League.

But while Liverpool ultimately had to settle for a fifth-place finish, the shift by Jürgen Klopp did produce results with Alexander-Arnold registering seven assists in his final nine games. Of the ten players with the most assists in the Premier League last season, Alexander-Arnold (10) and Robertson (8) were the only defenders to feature.

With Henderson and Fabinho gone, the question remains will Klopp be able to give Alexander-Arnold and Robertson the same licence as years past? Over the course of preseason, Mac Allister has been used as a deep-lying playmaker but doesn’t possess traits similar to Fabinho that transfer target Lavia does.

So, with it clear how integral their full-back duo are in creating chances, how do they fare defensively? Using PFF metrics and grading, we can assess how the duties of Alexander-Arnold and Robertson in attack reflect on those when in defence.

Trent Alexander-Arnold

PFF challenge grade: 71.2 (position rank: 26/87)

Of the 47 full-backs to have played a minimum of 1,400 in the Premier League last season, Alexander-Arnold was involved in the lowest number of challenges per-90 at 5.5. His win rate of 48% was marginally above the average of 46.8%.

An overall challenge grade of 71.2 ranks the England international 26th out of 87 full-backs. But to further contextualise his grade, if we take players at the position to be involved in at least the average of 170 challenge events, Alexander-Arnold is 22nd out of 41 players with a grade that remains good at above the 70.0 mark.

Given the general trend that teams in the top half of the league standings tend to be more accurate and high in possession volume, the table below charts players from the 47 who represented teams who secured a top-six finish.

Tackling: 73.5 (20/85)

The PFF challenge grade can be segmented to look at specific challenge event types, so if we look at how he graded on tackles Alexander-Arnold earned a 73.5 grade. This ranks him just inside the top 20 among all full-backs.

That turns into a more middling rank when searching for full-backs who were involved in the average number of events, 64, or higher. From his total of 86 graded tackle events, Alexander-Arnold’s grade ranks him 17th out of 41.

This is someway off of the criteria’s top three in Neco Williams (88.2), Marc Cucurella (87.2), and Serge Aurier (85.8), but comfortably clear of the worst-graded players in Renan Lodi (54.3), Nathan Patterson (62.2), and Jonny Otto (62.8), and shows Alexander-Arnold is capable of disrupting an opponent’s established ball carrier but not to an elite standard.

Defending dribbles: 84.8 (10/82)

No player at the position had to defend against more dribble attempts in 2022/23 than Liverpool’s Alexander-Arnold who faced a total of 99 dribbles and successfully defended 45. This results in a win rate of 45% which is marginally above the position average of 43.7%.

When Liverpool have been exposed defensively in recent seasons it has often been to long diagonal balls over the top which aim to utilise the space left in behind by Alexander-Arnold and Robertson. But when faced with an opponent looking to take him on, the 20-cap defender performed very well considering the level of volume in comparison to other defenders to play at least 1,400 minutes who averaged 48.8 defending dribble events.

His 84.8 defending dribbles grade ranks him inside the top 10 at his position and was an improvement on his 80.1 grade from the 2021/22 season.

Andy Robertson

PFF challenge grade: 68.5 (position rank: 36/87)

By the same criteria as used above with Alexander-Arnold, Robertson sees a higher involvement as a challenger on the left flank at 7.0 per-90 which ranks 42nd out of 47 players. This plants the Scot in between Aston Villa’s Matty Cash (7.1) and former Liverpool player Nathaniel Clyne (6.7).

Among those to be involved in at least the position average of 170 events, Robertson’s grade of 68.5 plants him 28th out of 41 players.

In the final games of the season where Klopp adopted the new midfield role for Alexander-Arnold in-possession, Robertson would move inside closer to the centre-backs rather than haring down the left flank.

The table below examines his performance in challenge metrics and grading over the span of matchday-31 against Leeds United to his final appearance of the season on matchday-37 against Aston Villa.

Tackling: 72.3 (23/85)

A PFF tackling grade of 72.3 ranks Robertson 23rd out of all full-backs, and 20th when limiting the criteria to players who meet the average number of tackle events – three spots behind Alexander-Arnold.

Last season saw Robertson make a clear improvement in this area to better his 2021/22 grade of 59.6.

Defending dribbles: 69.9 (56/82)

A dribbles defended win rate of 38% represented a drop-off from Robertson’s previous level of 58%, as he struggled to a 69.9 grade. This saw his year-on-year position rank fall from 34th to 56th.

Robertson faced a total of 39 dribble attempts, far below Alexander-Arnold and that of teammate Kostas Tsimikas (16). And while Tsimikas graded better when defending dribbles (72.3), his overall challenge grade of 61.1 trails Robertson’s 68.5.