Where, oh where have Boniface's goals gone?
Bayer Leverkusen’s nerveless 3-0 win over Werder Bremen was the sort to pass without notice, beyond the fact of consolidating Die Werkself’s lead at the top of the Bundesliga standings. Two things of note did take place, however; both involving striker and serial Rookie of the Month winner Victor Boniface.
The first was that he failed to score for the fifth match in a row, having announced himself in the German top-flight by averaging a goal a game over his first seven league appearances. The second was that he was substituted after 71 minutes, the earliest he has been removed from league action since making the move to the BayArena this past summer.
While there is certainly some mitigation in the form of the Europa League in midweek, it is difficult not to link both events. When once it seemed like Boniface was set to keep pace with the likes of Harry Kane and Serhou Guirassy, he is now a full eight goals behind the England striker and, for the first time this season, in a real funk.
The 22-year-old has enjoyed a seamless integration since his arrival, aided in part by the long-term injury suffered by Czechia international Patrik Schick, who has played a grand total of 29 minutes in all competitions this season. Schick’s compatriot Adam Hlozek is highly rated, but retains a raw streak, and so has been limited to deputising in Europe and in the DFB Pokal.
With not a lot to choose from beside, Xabi Alonso has nailed his colours firmly to the Boniface mast and, to this point, the Spaniard’s faith has been handsomely rewarded. Even outside of scoring himself, the Nigeria international’s goal contribution – only Xavi Simons and Leroy Sane have more assists than his five so far this season – has maintained his value to the collective.
Ultimately – and somewhat sadly – strikers are judged (and judge themselves) on goals, and that applies even for a player of Boniface’s unique skill set whose game is modelled on nippy, silken attacking midfielders. It would not do for this mini-drought to perpetuate itself, even if he has notched three assists in this fallow five-game stretch.
What then is to blame for his barren spell?
One theory states that Boniface displays poor judgement in his shot selection, letting fly with such abandon as to hamper his own chances of scoring more regularly.
To investigate that, this is a list of the 10 highest-scoring strikers in the Bundesliga, with their xG and shot numbers. Also included is their xG/shot, basically a measure of the (im)prudence of their shot locations – the higher the xG/shot value, the better the average shot location.
It does show that he shoots with greater frequency than any other striker in the top 10, and that his shot locations are more speculative than most. However – and this is important – compared to the Bundesliga average (0.121 xG/shot), he is not in egregious territory.
An alternative diagnosis centres on the claim that Boniface is a weak finisher in the first place, and that this accounts for his falling away. In fairness, it is easy to see why this theory has been put forward: no one in the Bundesliga has missed as many big chances (Opta defines a ‘big chance’ as one whose Expected Goals value is greater than 0.3xG) than he has: 15. The next worst culprit – RB Leipzig’s Lois Openda – has missed eight.
There is rather more to it than that, though. For one thing, the ‘Big Chances Missed’ stat is routinely led by the highest goal scorers. In the Premier League last season, no player missed more big chances than a certain Erling Haaland, who I am reliably informed is quite handy when it comes to putting the ball in the back of the net. The season before, it was Kane and Mohamed Salah topping the charts.
Get the message? The value is in being on the end of chances to begin with.
It is worth digging a little deeper. Aside from goal, xG and shot tallies, I have sought to measure two things. The first is how much value – objectively – the Bundesliga’s 10 highest scoring strikers are each individually adding to their shots. While xG measures the probability of scoring based on the shot location before the shot itself is taken, Expected Goals On Target (xGOT) measures the probability of scoring after the shot is taken based on its placement.
In simple terms, if a player’s xGOT is greater than his xG, that is probably a strong indicator of a good finisher, in the sense that, by taking the shot, he has added value to the opportunity. If xG is greater than xGOT, it indicates the obverse is probably true instead.
The second thing is goalkeeper performance. If a shot is on target, there are two possible outcomes: it is either scored or saved.
Therefore, by taking a player’s xGOT, and subtracting it from his goal tally, it is possible to gain an idea of how well opposing goalkeepers have done against the respective strikers. If, based on shot placement, a player’s xGOT is greater than his goals, that is a good indicator that goalkeepers have performed better than expected probabilistically. However, if the number of goals is greater than xGOT, it indicates the obverse.
The statistics show two things. One is that Boniface is, at worst, a competent finisher. While his finishing does not, on the whole1, add significant value to his shots, it does not detract from it either. By comparison, Harry Kane, Jonas Wind and Deniz Undav are finishing at an extremely high level going by the xG-xGOT metric.
The other thing is that, compared to the rest of the top 10, Boniface has been the victim of a significant degree of goalkeeper overperformance. Both he and Undav have negative G-xGOT values, indicating goalkeepers have performed better than historical and probabilistic expectations when facing their shots.
Kane and, especially, Guirassy are at the other end of the spectrum, in that goalkeepers have performed worse against them than one would expect on the basis of their shot placement. For Openda and Omar Marmoush, goalkeepers have performed roughly in line with expectation.
This all does a good job of disproving the prevailing notions about Boniface finishing, but that does alter the facts. Just how bad of a slump is this, and what might be responsible?
To begin with, beyond his lack of goals, it is easy to establish there has been a drop-off. If anything sets Boniface apart – beyond his high volume shooting – it is his dribbling: he is the only out-and-out centre-forward in the top 10 for successful dribbles per 90 (3.2, with a 58.1 percent success rate).
In the first seven matches of the season, he attempted 44 dribbles (an average 6.29 dribbles per game, success rate 54.55%); in the subsequent five matches, he attempted 21 (4.2 dribbles per game, success rate 52.38%). While his success rate has remained roughly stable, his propensity for the dribble has significantly decreased.
That is not the only thing that is down either. Since his utility outside of scoring goals has been established, it is also worth considering his shot-creating actions and their frequency as well. Over the first seven matches, Boniface had 26 shot-creating actions, an average of 3.71 SCA/game; over the subsequent five, he has had 14 shot-creating actions, an average of 2.8 SCA/game. That is a clear downturn.
Finally, a look at his other calling card: shots. Even here, there is a downturn: in the five matches in which he has failed to score, he took a total of 16 shots (adding up to 2.2 xG), an average of 3.2 shots per game. In the previous seven, he took a total of 44 shots (adding up to 8.1 xG), an average of 6.285 shots per game. His shot output has, more or less, been halved.
It is not, as some might suspect, that opponents have sussed him – or Bayer Leverkusen – out either. A look at touches: he has averaged 35.6 per game over the last five, and 38.5 per game over the previous seven. He is getting as much of the ball as he always did, but is (a) being less dynamic with it, and (b) taking fewer shots.
There are, in light of this downward trending data, two major possibilities. The first is that the change in his play is down to instruction: perhaps Xabi Alonso has corralled his instincts somewhat, in a bid to make the team more secure against turnovers. Leverkusen have gone from giving up 1.04xG per match through the first seven, to 0.84 over the course of the last five, so there is probably something to that idea.
The second possibility is that Boniface is carrying some type of injury or is suffering a bit of fatigue. It is interesting that the October international window signalled the start of his lean spell of form; at the risk of reading too much into things, it is quite possible he is nursing some discomfort, and is having to play somewhat within himself in order to not aggravate it.
Or it could just be a blip, one that will resolve itself sooner rather than later. In that case, Borussia Dortmund best beware on Sunday.
Interestingly, on the relationship between xG and xGOT – and to further address the idea that Boniface is a weak finisher – my perusal of the data brought this nugget to my attention: of the 13 shots taken by him that missed the target completely from inside the box, only four were taken by his right foot.
It got me thinking, so I put the xG and xGOT values of all of Victor Boniface’s unblocked shots, sorted them by right foot, left foot and head, and tallied them up.
Sure enough, this shows the main issue with his finishing: he adds significant value to shots taken with his right foot, but loses quality overall on shots taken with his left and head. If there is a weakness to his finishing, it correlates more with his weaker foot – and underdeveloped heading technique – than anything else.