The most important game of the season in Bundesliga is almost here as Bayern Munich host Borussia Dortmund in a potential title-deciding Der Klassiker.
As things stand, Dortmund are on top of the table with 63 points and Bayern are not far behind with 61. With just seven games left, it’s fair to say that the winner of Der Klassiker could possibly go on to clinch the title.
But how did the teams get to where they are? Did luck play a part in shaping the points table? We take a look at the numbers behind their seasons.
The concept of xPTS (Expected points)
The concept of xPTS is similar to xG (Expected goals) and xGA (Expected goals against). It’s a number between zero and three, which gives information on the amount of points a particular team should have won in that game based on the quality of chances created and conceded.
Data from xG and xGA can be used to simulate the game over 1000-10000 times to arrive at the decimal which corresponds to the total points the tam should have won in that game. Luckily, we were saved from writing the code as the numbers were available at understat.com.
Needless to say, a team with xPTS close to three were the better team that created better chances, conceded only a few and dominated the game on the whole.
Bundesliga teams and xPTS
The positive difference of PTS over xPTS (Actual points and expected points) can be attributed to a team being rather fortunate. A negative figure here means that the team was unlucky and deserved better.
In the graph, we have xPTS on the x-axis and PTS-xPTS on the y-axis. This means that teams which have performed well and have gotten lucky will lie in the first quadrant, with Dortmund leading the line. Teams which have performed well but have been unlucky fall in the fourth quadrant and Bayern are the leaders in this category.
To put it in numbers, Dortmund have accumulated 63 points, while their XPTS is just 51.34. This means that they have been able to garner 11.66 ‘lucky points’. Bayern, on the other hand, should have had 63.92 points, but have won just 61 points. The Bavarian club have been slightly unlucky and should probably have been table-toppers.
It’s interesting to note that RB Leipzig have an xPTS of 51.59. which is marginally greater than Dortmund’s. Statistically speaking and subtracting the ‘lucky’ points, Leipzig should have been second on the table, ahead of Dortmund.
Are Dortmund getting lucky or are they creating their own luck?
It’s easy to sit behind a computer screen and label a team which is on the verge of ending Bayern’s monopoly as ‘lucky’, right? However, Dortmund are – in a way – creating their own luck.
In the 2016/17 season, NICE finished third in Ligue 1 with 78 points. Their xPTS in that season was 53.47. This means that they earned 24 ‘lucky’ points. Who was their manager at that time? Lucien Favre. At this point, it would be prudent to attribute the vast difference to Favre’s style of play.
Dortmund have managed to win some games even when their xPTS was lower than that of their opposition’s. The most notable example of such a game was when they beat Augsburg 4-3 at home.
Dortmund’s xPTS in this game measured just 0.76, while Augsburg’s was 2.06. Dortmund had scored three goals after 75 minutes in this game. So, are Favre’s men creating their own luck at the death?
Dortmund have scored 66 goals this season at an xG of 51.29. What’s interesting is that they have scored 20 of them after 76 minutes, while the xG generated in that time period of games is just 9.86. They have scored more than twice their xG in the closing stages, which is really impressive.
In contrast, Bayern have scored just 12 goals after 76 minutes, at an xG of 14.81. It’s fair to say that Niko Kovac’s men have not made the best of their chances in the death. It’s also worth noting that Dortmund have scored 20 goals from 77 shots in the last 15 minutes of games, whereas Bayern have managed to net just 12 of the 85 shots they took.
Robert Lewandowski
Whether it’s lack of service to Robert Lewandowski or the Polish international’s inability to convert chances that he should, Bayern have only themselves to blame.
Ultimately, the goals in the last 15 minutes have separated the two sides. Dortmund’s clinical finishing and superior mental fortitude has allowed them to clinch games at the death.
The tale of Paco Alcacer and Robert Lewandowski
It takes consistent clinical finishing from a top player to register more goals than what his xG suggests. The presence of such a player could also account for some of the ‘lucky’ points Dortmund have accumulated.
Alcacer has been in fine goal-scoring form this season.
Paco Alcacer has scored 16 goals this season at an xG of 8.93, over-performing with a difference of +7.07. Lionel Messi – of course – is the only player in Europe’s top five leagues to have a bigger difference (+9.44).
Alcacer’s profligacy in front of goal is yet another reason Dortmund find themselves where they are and where they arguably deserve to be – top of the Bundesliga table.
On the other hand, Lewandowski has managed to score just 19 goals at an xG of 27.60. Clearly, he has terribly underperformed and the difference of -8.60 sums it up.
The trend does not look good for Dortmund
This graph shows the variation of ‘lucky’ points over time for Dortmund and Bayern. While Bayern show no distinct trend, it’s clear that Dortmund’s ‘luck’ is running out. In the last two months, they have won just about as many points as their xPTS has suggested they would. It’s not surprising that it was during this period that they temporarily conceded the top spot to Bayern and slacked off.
Favre needs to ensure that this trend does not continue and Dortmund get back to creating their luck once again. This could be crucial for them in the title race.
