Diving into the numbers behind Barça’s chance conversion to evaluate whether or not steps can be taken towards improvement.
Oftentimes this season, it has seemed as though Barça have left points on the table due to poor finishing. Now that the La Liga title is officially out of reach, this can be even more of a frustrating topic. However, what portion of Barça’s shortcomings this season can truly be attributed to poor finishing or bad luck in front of goal? Have the team really been un-clinical, or is this just selective memory from the fanbase?
To try and answer these questions, we can look at how the team has scored relative to their expected goals (xG). This metric measures the likelihood of each shot resulting in a goal based on a variety of different factors, including its distance from the goal, the angle, the body part being used, and the positioning of defenders and the goalkeeper.
As such, looking into actual goals scored compared to the expected tally can provide insight into how Barça’s season has gone finishing-wise. Additionally, examining this on an individual level can help us see if a new signing could fix any potential issues. With that in mind, what do the numbers say?
Barça in 2020/21: Clinical or not?
This season in La Liga, the side have accumulated 72.3 expected goals with penalties excluded. To reiterate, this number represents the most likely outcome for goals scored based on the quality of the shots the team has taken. Then, as it turns out, those shots have actually yielded 75 non-penalty Barcelona goals.
So, on a basic level, Barça have not experienced major issues when it comes to converting chances. However, when comparing this overperformance of 2.7 goals (or 0.48 per 100 shots), it becomes apparent why supporters feel a bit of clinicality has been lacking.
This season, the Blaugrana have created scoring chances at a higher rate than in the previous two campaigns. As mentioned before, the team is still converting at an above-expected rate, but this is much lesser than in the past few years.
The 2017/18, 2018/19, and 2019/20 seasons saw significantly higher xG overperformance. For every 100 shots the side took, they scored up to three goals more than the most likely outcome. Now, though, that has dropped to less than half of an “extra” goal.
How much can really be made from this drop-off, though? Finishing in football can vary massively due to simply randomness or luck. Many teams go through even more dramatic season-to-season changes than Barça, and there are quite a few high-profile examples of this in recent years.
Liverpool, for instance, outperformed their non-penalty xG by over 1.7 goals per 100 shots in each season from 2017/18 to 2019/20. But, this season, that has flipped to an underperformance of around 1.7.
In the 2017/18 Bundesliga, Borussia Dortmund slightly underperformed their non-penalty xG by 0.04 goals per 100 shots. In the next two seasons, though, their finishing rose to insanely high levels of overperformance by 4.66 and 5.44 goals per 100 shots. Finally, this season, they have started to cool back down but still sit at a plus 1.31.
With all this in mind, it would be generally unfair to pin Barcelona’s failures on a lack of clinicality. The likes of Juventus, Paris Saint-Germain, Real Madrid, Sevilla, RB Leipzig, Chelsea, and Liverpool have all had more finishing woes statistically this season. However, it is fair to say that an advantage which Barça sides in previous years have possessed pretty consistently is no longer present, at least not to the same extent.
Opposition goalkeepers have stepped up
Going further with the point of luck being involved in finishing, the play of the opposition goalkeeper is one factor that is out of the team’s control. In Barça’s case, this is certainly playing a part.
This can be seen using post-shot expected goals (PSxG). PSxG is used to evaluate goalkeeper shot-stopping performance, as it takes into account things like the velocity and shot height after the ball has been struck.
Goals saved above average (GSAA) – how the goalkeeper has performed relative to their PSxG conceded per 100 shots – clearly shows that opposition goalkeepers have been much better against Barcelona in 2020/21 than in previous seasons.
While past campaigns saw goalkeepers struggling against Barça and letting in far more shots than they were expected to, the script has flipped a bit this season. Thus, at least a portion of the team’s finishing “decline” can be attributed to better goalkeeping. This, of course, can not be improved or fixed by the Barcelona players themselves.
Messi vs. the rest
While so much of finishing has to do with hot streaks, luck, and randomness, Lionel Messi is one of the anomalies who consistently manage to score far more than he “should.” Comparing Messi to the rest of the team does show some of the dependence on his ridiculous finishing level, but it also provides a bit of reason to be optimistic.
In each season, Messi has, of course, outperformed his expected goal tally by a sizeable amount. The rest of the squad has largely been quite clinical, too, outside of this current season.
Thus, upon removing the Messi factor from the equation, you can get a clearer picture of how the likes of Frenkie de Jong, Martin Braithwaite, or Antoine Griezmann, despite his improved form, could have bagged a couple more goals each this season. If we can consider Messi’s overperformance to simply be accepted and counted upon, not due to luck and bound to regress, this could leave room for improvement heading into next year.
Could a new signing help?
In addition to certain members of the “supporting cast” potentially rebounding in 2021/22, could Barça become more clinical with some transfer activity? If there were other anomalous finishers like Messi out there, it would certainly be beneficial to have one more in the side.
But, that’s the thing, Messi’s ability is so rare, and finishing trends can be so hard to predict that it is almost impossible to definitively say, “We should buy this player so we convert our chances at a higher rate.” This pair of graphics illustrate some of the uncertainty involved:
on the left we've got basically every crazy single season finishing performance of the last seven years, and on the right we have the career finishing for the players that enjoyed a season that qualified for the graph on the left pic.twitter.com/gdIaP1ekB8— Kees van Hemmen (@HemmenKees) May 13, 2021
*NOTE: These visualisations use data from Understat. Their xG model is not as advanced as the one used on Football Reference (From Statsbomb) and can tend to underestimate xG for top teams. This means players in those top teams can have a bit of an easier time overperforming.
While this comes from a different data provider and shows a different timeframe, the trends are important. Essentially, players can have a season of very good to ridiculous finishing, but over the course of the careers, be on more of an average or below-average level.
The inverse of this is also true. Sometimes players who are statistically above-average finishers over the course of their career will have a cold stretch, which could potentially last the course of a season.
Here, you can see the cumulative finishing – going back to 2017/18 – of some of football’s highest-profile attackers, as well as some names who have been strongly linked to Barça:
Starting at the bottom, Gabriel Jesus and Lautaro Martínez reflect that the value of some great strikers does not even come from their finishing. Obviously, they contribute in other facets of the game than scoring. Still, they can rack up very commendable goal tallies because they constantly get in the right positions, not because they are elite or even above-average finishers.
A bit further up, one can see that someone like Cristiano Ronaldo, widely regarded as one of the best goal scorers in football, would likely have had a marginal effect, if any, on the level at which Barcelona actually converted their chances in the past few years.
Once again, players like Ronaldo and Robert Lewandowski can obviously help a team score goals. Still, most of that will come down to their movement and positioning, leading to many additional chances, not because they would finish the “existing” chances at a ridiculous rate.
Even some of the players higher up, who look like very good finishers over this period, have had their fair share of season-to-season variance. Mohamed Salah, for instance, tremendously outperformed his xG in the 2017/18 season, yet in 2019/20 (and 2019/20 and 2020/21 combined, even), he has underperformed.
In the 2018/19 La Liga season, Luis Suárez underperformed his non-penalty xG by a total of 1.0 goals before jumping to a total overperformance of 1.8 goals in 2019/20. There was no way to predict another significant jump and his hot streak this season, which has put him at 4.5 non-penalty goals over his expected tally since his move to Atletico Madrid.
With this in mind, there is no way to fully guarantee an uber-clinical signing. However, those two names at the top of the chart would be the safest bets if that is what the club were looking for. Tottenham teammates Harry Kane and Son Heung-min are probably the two anomalous finishers in the world who start to approach Messi’s level. It is worth noting that Kane has already been linked to Barcelona.
As for Erling Haaland, We will have to wait and see more of him since he is just finishing his first full campaign in the big five leagues.
Since the start of the 2017/18 Premier League campaign, Son’s finishing has added a total of 15.8 “extra” non-penalty goals over the most likely outcome, while Kane is at 14.3. They have outperformed expectations in the long term and in each individual season.
Thus, bringing in the Englishman or the South Korean would be the surest available option if Barça wanted to add goals through finishing. However, even when ignoring their transition into a new system and how they would slot into the side, paying massive fees and wages on another attacker closing in on age 30 (Son is 28, Kane turns 28 in July) does not seem like the smartest move.
As boring and unspecific as it may sound, strengthening the team structurally is likely to be the most beneficial option. Incremental improvements to progression, incisive passing, and poaching, which could still lead to a new forward being brought in, can generally lead to the creation of more, higher-quality chances, and thus more goals.
Defensive improvements and filtering out individual mistakes – the source of far too many opposition goals – will also help greatly reduce the impression that Barça squander opportunities to win.
Furthermore, it is important to start to look ahead to a future without Messi. When the squad eventually loses this one supernatural-esque finisher, that will be several crucial goals each season out the window. The most surefire way to cope with such a loss will be strengthening the squad as a whole and looking to create more chances.
To recap, Barcelona have not severely struggled to finish chances this season. Many other sides, including several big clubs, have had a worse mixture of luck and finishing form during the 2020/21 campaign.
However, compared to the last few seasons, there has definitely been a drop-off at Camp Nou. One unlucky, uncontrollable reason for this is the improved form of opposition goalkeepers, while the down year for the supporting cast of finishers around Messi has also played a part.
Ultimately, there is not a 100% certain fix for this. Finishing is such a microcosm of the game that it can be very random over shorter samples, and players are prone to many hot and cold stretches. Kane and Son seem to be the closest thing to Messi finishing-wise, but would taking on their costs and fitting them in the squad as they approach 30 be worth the extra few goals their finishing would likely provide each season?
In the end, the right path forward seems to be to strengthen the squad in general in the hopes of creating more chances (and conceding less), not converting the same chances at a higher rate. One of the key factors to be considered here is whether or not Messi stays at the club.
This does not necessarily mean that a nine or a goal-scoring forward should not be signed, as many of football’s most consistent goal threats help their team score more by getting into the right positions and getting on the end of a multitude of dangerous passes. But, it means the club should not just be looking to sign a lethal finisher, as opposed to making the right decision in the long term.