While expected goals (xG) continues to gain popularity within the wider footballing landscape, its little brother, expected assists, has remained in the shadows. We have already used expected goals to analyse how the remainder of the 2019/20 season could play out for Europe’s top strikers. Now we turn out attention to how expected assists can help us analyse Europe’s top playmakers.
The expected assists (xA) metric measures the underlying creativity of a player’s passes. We can use xA to determine how many assists a player should have if his passes were converted by teammates at an average rate, thus rewarding players who may have been undervalued by simply looking at total assist numbers. Kevin De Bruyne, Thomas Müller, Jadon Sancho and Angel Di Maria are currently leading the assists race. But do they deserve to be that high? Will they keep that pace and who will end on top? Let’s take a look.
What’s striking at first is how close De Bruyne and Müller are in terms of assists and xA, with the Citizen only slightly ahead of his German counterpart in the latter category. Both should have delivered between 10 and 11 assists, but in reality they have 16 each because they’re finding teammates that are finishing at a better than expected rate.
The difference between the pair lies in the quality of the chances that they have created. While De Bruyne has created 96 chances in 26 games in the Premier League (more than any other player in the Top Five European leagues) and Müller has created 36 fewer in 25 Bundesliga games, the quality of the chances that Müller has created is much higher (0.17 xA per chance created v 0.11 for De Bruyne).
It remains to be seen whether both players can maintain this level of creativity when football returns, but both are currently assisting at a rate where they would total 22 assists each and eclipse their respective domestic records. De Bruyne could comfortably overtake Thierry Henry’s Premier League record 20 assists in 2002/03 but may simultaneously see his own Bundesliga record of 21 assists – set while playing for Wolfsburg in 2014/15 – surpassed by his German rival. While Müller’s form has put him on track to take De Bruyne’s Bundesliga crown, his frequent appearances from the bench may hinder his opportunities in what is likely to be a very busy schedule for Bayern Munich’s nine remaining fixtures.
Unlike xG, a player having more assists than their xA does not necessarily mean they’re overperforming individually because the conversion of their passes into goals is dependent on the players receiving these passes. Jadon Sancho is demonstrating this more than any other player.
While Sancho has the third best goals minus xG differential, he also has – by far – the biggest assists minus xA differential in Europe (+8.6). This means he has delivered eight more assists than the quality of his final passes would suggest. He can thank Paco Alcácer, Marco Reus, Achraf Hakimi and of course Erling Haaland for that. His teammates have converted five shots with an xG value less than 0.1 (a shot with less than 10% chance of being converted) following his passes. As shown in the graphic below, some of Sancho’s assists have ended outside of the box, confirming the finishing abilities of the players receiving his passes.
Between Aug. 17 and the Sept. 14, 2019 for instance, four of his seven chances created ended in a goal. The English youngster is not the only one to profit from the efficiency of his colleagues. In fact, seven of the 10 players with the most assists are among the top eight players with the biggest assists minus xA differentials.
Let’s now take a look at players with 30+ chances created in the Top Five European leagues. Two individuals stand out in terms of quality. As mentioned, Thomas Müller has the best xA per chance created (0.17) among the Top 10 players with the most assists. The only players with a better ratio this season are Serge Gnabry and Kylian Mbappé who have been delivering chances with an average xA value of 0.22. Despite this, the Frenchman has only five assists to his name when he should have registered closer to nine, a high tally partly explained by how many chances he’s created from inside the box. His xA differential (-3.8) is the third worst in Europe this season. Edinson Cavani, who has missed three chances created by Mbappé with a xG value of greater than 0.6, might be the one to blame here.
Moreover, Mbappé’s relatively high xA is made all the more impressive considering his chance creation comes from open play while leaving set pieces to Neymar and Di Maria.
When it comes to talking about creating chances from set pieces, look no further than Trent Alexander-Arnold. The Liverpool right back has delivered seven assists from corners and free kicks. No other player has more, and only 16 players have more assists altogether. However, his xA from set pieces is only 2.3. Having man-mountain Virgil Van Dijk as the target man certainly makes life easier, and three of Alexander-Arnold’s seven assists from set pieces were scored by the Dutchman.
The only other player with seven assists from set pieces plays for Union Berlin. Introducing Christopher Trimmel. His xA from set pieces (4.9) is more than double Alexander-Arnold’s. In addition, his xA per chance created from set pieces is also twice as high. Considering the quality of the Liverpool right back, one has to take the threat Trimmel poses on set pieces seriously, especially when Sebastian Andersson is on the other end. Five of those assists have set up goals for the Swedish striker. Bundesliga defenders beware.