When Jadon Sancho arrived at Manchester United in 2021, he was coming off the back
of an impressive season in the Bundesliga with Borussia Dortmund. In just over 2,000 minutes,
he had picked up 8 goals and 11 assists at a rate of 0.83 goal involvements per game
which put him in the top 5th percentile. His underlying numbers were equally impressive:
0.32 expected goals per 90 and 0.3 expected assists per 90 was a good enough return to
earn the youngster a £77 million move to one of the biggest clubs in the world.
A season later and Jadon Sancho’s stat line makes for miserable reading.
Over a similar number of minutes in the Premier League last season, he only managed 3 goals
and 3 assists, at a rate of 0.28 goal involvements per game - an eye-watering reduction of around
66 percent which put him outside of the top 30th percentile for that metric. Unsurprisingly, his
underlying numbers had enjoyed a similar albeit slightly smaller decline of around 40 percent.
Although this downturn is undoubtedly impacted by Sancho moving to a struggling Manchester United,
it may also be an example of a curious phenomenon that occurs when players move from the Bundesliga
to the Premier League: a phenomenon known more colloquially as the “Bundesliga Tax”.
Bundesliga Tax refers to the drop off that occurs when a player moves from the Bundesliga
to the Premier League. In recent years, it has been offered as an explanation for the
disappointing performances of Timo Werner and, to a lesser extent, Kai Havertz at Chelsea.
This summer, one of the highest profile transfers into the Premier League
is that of another Borussia Dortmund player, Erling Haaland, to Manchester City. So,
the question is: will Haaland prove to be another victim of Bundesliga Tax?
So, although the concept of a Bundesliga Tax emerged from
fan discussion, professional football analysts have since spent time looking at the numbers
to see if it’s a real thing. For the most part, these analyses have focused on creative output,
largely because goal scoring and creation numbers are easier to track in the data.
Analyst Tony ElHabr has suggested that a player moving from the Bundesliga to the Premier League
can expect a drop of around 0.07 expected goals per game. This may not sound like much,
but in the course of a season where a player makes around 30 appearances,
that adds up to a reduction in expected goals of around 2.
But of course, goalscoring numbers aren’t everything. Many analysts use what are
called Possession Value models to assess the way that all of a player’s on-ball actions
impact the game. Using one of these models, Tony ElHabr estimates that Bundesliga players
will experience a 17% decrease in their output after a move into the Premier League.
So, as far as the numbers are concerned, the Bundesliga Tax does seem to exist.
However, It is worth noting that ElHabr’s research also shows that similar ‘taxes' exist for players
moving to the Premier League from Portugal, Italy, France and Spain, suggesting that,
instead of singling out the Bundesliga, maybe the tax should in fact be called a Premier League Tax.
This shows up anecdotally if you look at the ten most expensive imports into the Premier
League from the Big Five European leagues: players like Romelu Lukaku, Paul Pogba, and Nicolas Pepe.
With the exception of Kevin De Bruyne (and Erling Haaland, who we’re yet to see play in the league),
it would be hard to argue that any of these signings really lived up to expectation. So
you see, it’s not just Bundesliga players who struggle to accommodate themselves
in the Premier League. It’s players from all across the big five leagues.
But how do we account for those players who successfully make the switch?
In his final season at Wolfsburg, De Bruyne put up 0.89 goal involvements per game. Although
this figure did decline in his first season at Manchester City, he has also had seasons at the
club where his goal involvements per game have been higher than his best season at Wolfsburg.
For instance, this season, his goal involvements per game were up at 0.94. Unlike Jadon Sancho,
though, De Bruyne was moving to a very successful side in Manchester City. It’s clear that in some
instances, then, the strength of the team that the player is moving to can cancel out the tax.
There are other factors to consider: if you’re bringing in young players,
you might expect their output to increase naturally as they develop.
This also might work towards reducing the impact of a Bundesliga tax.
To relate this back to Erling Haaland: he's joining the same team that De Bruyne excelled in,
and is young enough that we might expect him to improve as he approaches his peak years.
He has also performed well in Europe against non-Bundesliga teams. This will give potential
suitors confidence that a player is ready and able to make that jump. And in the case of Haaland,
Manchester City will hope this means he's more of a de Bruyne, than a Sancho.