By Robbie Butler

The annual European gathering of sports economists kicks off in Innsbruck, Austria, today. The event – now in its 16th cycle – is the largest of its kind in Europe.

The full programme – which includes some 57 different paper presentations across a diverse array of areas and sports – can be accessed here. Our paper – a collaboration with David Butler and Katrin Scharfenkamp of Bielefeld University, Germany – is called "Back in the Game? ACL Recovery and Performance in Women’s Professional Football."

Our research seeks to complement ongoing studies on presenteeism by charting the impact of ACL injuries on player performance upon their return. Specifically, we are exploring whether there are losses to female football players’ post-recovery productivity compared to pre-ACL-injury performance due to presenteeism. We access player-match-level data of female football players’ ACL injuries and advanced performance statistics in European leagues (e.g., WSL, Frauen-Bundesliga, Liga F), as well as the NWSL and A-League, from 2017–2025. These players are then compared to a control group of injured players.

The paper is due to be presented this afternoon and will be followed by the AGM. This year will see the election of a new committee and president-elect. 

By Robbie Butler

The transfer saga now surrounding Alexander Isak is something many football fans will have seen before. Names such as Harry Kane, Dimitar Berbatov, Carlos Tevez, Neymar — the full list is much longer. It is interesting that Isak is a Newcastle United player. The club has been here before. In fact, they were probably the genesis of the original shift towards player power.

In the early 1960s, England international George Eastham took on Newcastle United and the football establishment in a case that would change the game forever. At the time, the “retain-and-transfer” system meant that clubs could keep a player’s registration even after their contract expired, effectively binding them indefinitely and preventing them from signing elsewhere. Eastham, unhappy with conditions at Newcastle and denied a transfer, went on strike, working outside football while waiting for the club to release him. Although he eventually moved to Arsenal in 1960, he pursued a legal challenge with the backing of the Professional Footballers’ Association, arguing that the system was an unfair restraint of trade.

In 1964, the High Court agreed, ruling that the retain aspect of the system was indeed unreasonable. While Eastham didn’t personally receive a big payout, his victory dismantled one of the most restrictive labour controls in sport and led to fairer contractual terms for players, including the creation of transfer tribunals. The case paved the way for greater player autonomy, influencing landmark rulings like Bosman decades later. Eastham’s stand is remembered as a turning point in football history — the moment the game began moving from “slavery contracts” toward the modern era of player rights.

Bosman is someone that people are much more familiar with, and soon maybe Lassana Diarra. I wrote about this last year. In December 2024, FIFA introduced an “interim regulatory framework” to address the court’s concerns. This covers compensation for breaches, joint and several liability, issuance of International Transfer Certificates, and tribunal proceedings. However, it is far from over. Now, it’s up to Belgian courts and football stakeholders to translate the ruling into lasting, practical changes for player transfers and contractual freedom.

Is this where Isak is going? It is reported he has 3 years left on his contract. As Diarra has shown, this should be meaningless. The French player’s win in the European court means that the current rules effectively impede the free movement of labour and the rules “do not appear to be indispensable or necessary.” So a player could potentially walk away from a contract without compensation for the club holding the contract. This is no different from almost any job: work a period of notice and then leave — for free.

If compensation were required, it could be calculated as the value of the remaining contract. If a player is owed £20 million in wages, the player or their agent could compensate the club to this value and say this is what the player is worth. If the club were to argue otherwise, the player could ask why they were not paid their ‘true value’.

Of course, this remains all hypothetical. At least, for now.

By David Butler

​Some months back I had an entry on football standards across divisions. I charted the output declines of top scorers contracted to promoted clubs upon reaching the top of the football pyramid. On average an expected goals rate of ~15 reduces to ~5 when strikers move to the elite tier in England. About 6 assists per season reduce to about 2.

Of course Arsenal's new star signing Gykores is not contracted to a promoted club, so this ‘extreme’ deflator would not be applicable, but it is unlikely he will replicate his past 4 seasons xG and xA form that took place in lower quality leagues. Expectations seem very high given his scoring rate and performances, but will we see an xG of 19.2 and 19.5 (Coventry – Championship)  or 22.5 and 30.8 (Porto – Primeira Liga)? I doubt it. 

By John Considine

The picture below is taken from last month's edition of Oxford Economic Papers.  The article by Finn Spilker and colleagues is titled "Favouritism, social pressure, and gender".  The relative position of the Xs and Os tell much of the gender story that is examined in the article.

It is a picture worth thinking about.  Some obvious questions spring to mind.  Why should there be less added time for games with a bigger score difference?  To generate a score difference requires goals.  We are led to believe that the greater the number of goals then the greater the amount of added time.  Why is there an increase in time added in games with a 1-goal difference compared to a game that are level?  Related to the previous question, why are the Xs above the Os only for 1-goal differences?

The article is worth a read.  But the picture below is worth at least 1,000 words.

By Robbie Butler

With many new football seasons about to kick-off, readers here might also be interested in reading Football Statistics.  This blog - maintained by Dan Brown - has some really interesting material.

Dan graduated from the University of Oxford with a PhD in Economics and is an avid football fan. As he says himself: "the main focus of this blog, I test football clichés with data. Accompanying each short blog post is a link to a more in-depth analysis for interested readers."

He also uploads his Stata code for replication purposes. This is a really useful tool and could be very helpful to undergraduate and postgraduate economics students trying to engage in sports economics research. 

The most recent post on the blog - "Quantifying the dark arts: How do players steal yards at free kicks?" - can be found here.

By John Considine

One of the sports economics books that I most enjoyed reading is Beautiful Game Theory.  The title is a clever combination of Game Theory and the Beautiful Game.  The subtitle is "How Soccer Can Help Economics".  One way soccer can help economics is by using data from the beautiful game to test economic game theory.  Penalty kicks feature prominently in Beautiful Game Theory as a way of examining if humans can make decisions in practice as suggested in theory.  But one needs to be careful because the data is being shoehorned to match the theory.

The economic game theory used presumes that the interaction between penalty kicker and goalkeeper is a simultaneous game.  It is not.  It is close but the decisions are not made simultaneous.  To illustrate examine the penalties in this video brought to my attention by Robbie Butler.  Below is an image from the video.  The goalkeeper has obviously begun the process of diving to his right (to the left as we look) before the ball is kicked.  The ball is being kicked after the keeper has started his dive.  The dive and the kick are not simultaneous.  The decision about which side to kick the ball does not have the uncertainty presumed in deriving the minimax solution.

Relying on penalty kicks to test if players play minimax is less than ideal.  Ignacio Palacios-Huerta, the author of Beautiful Game Theory, understands this issue.  The first chapter is titles "Pele Meets John von  Neumann in the Penalty Area".  Here the economist takes data from previously played games of soccer.  The second chapter overcomes the problems identified above by taking soccer players to a laboratory to see if they play minimax in a different setting.  Here the players play a game designed by the econo mist.  The chapter is called "Vernon Smith meet Messi in the Laboratory".  The sequencing of players and economists names in both chapters is not an accident.

Palacios-Huerta understands the difference between simultaneous and sequencial games.  He famously advised the Chelsea goalkeeper not to dive early when facing Ronaldo in the 2008 Champions League Final.  Ronaldo did not score.