Monday, 1 September 2025

The silly season: A numbers game

As August gives way to September and the media’s so-called “silly season” winds down, attention shifts to the return of football. With the new season having kicked off, and today’s transfer window now having closed, it can sometimes feel as though a different kind of silly season is only just beginning. Yet football is merely a reflection of our society with its passions, excesses and contradictions. The sport magnifies our tribal instincts, celebrates collective joy and exposes the widening gulf between ordinary fans and the vast sums of money that swirl around the game. It is also – as I have frequently noted – a great test bed for applying economic and statistical analysis.

Some economic reflections on this year’s big stories

While football can provoke great debate, it is just as likely to be treated with indifference by a large section of the population. But it is hard to ignore. Even the Financial Times is taking notice, with its fun online challenge (Can you run a Premier League football club?) and an article equating the decline of Manchester United with the fall of the Berlin Wall. I have long thought that the diminished prowess of the Red Devils speaks more to the industrial economics literature on why dominant firms decline. Empirical research conducted by Paul Geroski in the 1980s[1] challenged the conventional view that dominant firms do indeed decline. Paul is alas no longer with us, but he did develop a surprising affinity for football, and he would almost certainly conclude that Manchester United’s recent travails do not represent a permanent shift in the club’s fortunes.

To the sports journalist or the casual fan, the standoff between Alexander Isak and Newcastle United, in which the player’s refusal to train with the team as he tried – eventually successfully – to force a move to Liverpool, may seem like the petulant actions of a spoiled star. To the economist, they represent calculated moves in a high-stakes financial negotiation. Isak’s motivation is clear: moving to one of Europe’s top clubs will propel him into the footballing elite, generating more trophies and a higher income. A footballer’s career is short, and could be ended tomorrow by injury. It is thus rational for him to attempt to maximise his income.

What about the clubs? Newcastle are about to reap the benefit of Champions League revenues, and must weigh the immediate windfall of a record-breaking player sale against his value on the pitch, where his contribution could see the team progress further in the competition thus generating additional broadcast, matchday and win-related revenue. For their part, Liverpool must balance ambition with fiscal prudence. A blockbuster signing is no guarantee of success and the club must be careful that a fee in the region of £130 million does not undermine their carefully maintained financial model under the Premier League’s Profit and Sustainability rules (PSR).

Indeed, one of the features of the transfer window – the player trading period that closed today – is what it reveals about how modern football teams manage assets, revenue streams and strategic risk. The economics of football transfers are increasingly shaped not just by player ability but by contract dynamics. The Isak case is unusual because he had three years left on his contract. But when a player has only a year left on his deal, his transfer value typically falls sharply because the selling club risks losing him for free under the Bosman ruling. This shifts bargaining power towards the player and the buying club: the player can threaten to run down his contract, forcing a cut-price sale, while suitors know they can secure him on a free the following summer. As a result, clubs often face a strategic dilemma – cash in now at a reduced fee, or gamble on retaining the player’s services for another season and risk losing a valuable asset without compensation. In a financial landscape constrained by PSR regulations, these contractual time horizons are as important to balance sheets as the players’ performances on the pitch.

The real action is on the pitch

While much of the economics focuses on the finances, the action on the field lends itself to statistical analysis. Last autumn, I took a look at Premier League prospects for season 2024-25 on the basis of a Poisson simulation model[2]. How did I do? First the bad news: I gave Liverpool only an 8% chance of winning the title (they won comfortably). More positively, I tipped the five clubs who would win Champions League places; correctly predicted two of the three relegated teams and called 8 of the top 10 teams. I will leave it to the reader to judge whether that was an acceptable performance.

The method has a substantial academic pedigree[3] and last year’s performance was sufficiently robust that it is worth trying it again as a means to forecast outcomes for season 2025-26. As a reminder, the model simulates each game 1000 times and adjusts expected goals (λ) by adding a random number in the range [-1<n<1] in a bid to capture the element of luck inherent in any sporting contest. The results are shown in the table below.

Even before a ball was kicked, the model suggested that Liverpool were favourites to retain their title (57% probability, or evens favourites) with Arsenal, Manchester City and Newcastle making up the rest of the top 4. The unfortunate favourites for relegation are Burnley, Wolves and Sunderland (probabilities of 47.5%, 45% and 76% respectively). It is notable that the pre-season rankings generated by the model broadly accord with the bookmakers rankings. In the chart below, I use the bookies odds of achieving a top 4 finish as a proxy for team’s relative strength. In cases where the club is placed above the diagonal line, this represents cases where the bookies are more optimistic than the ranking predicted by the model (take comfort fans of Tottenham and Manchester United). Similarly for those clubs placed below the diagonal, the bookmakers are less optimistic (fans of Leeds, Brentford and Bournemouth take note). Given that last year’s results form the basis of the model’s expected goals parameter (λ), and the weight of money placed with the bookmakers is heavily influenced by last year’s performance, congruence in the results should not be a great surprise.

One of the weaknesses that I tried (unsuccessfully) to address is the momentum effect. If a team starts the season well (badly), does it represent a temporary deviation from the mean or does it represent a genuine improvement (deterioration) in performance relative to last season? In an attempt to address this problem, I experimented with a dynamic estimate of λ based on an exponentially weighted average of recent performance. In this approach, the starting value for λ is last season’s average although over time this plays a diminishing role. Early random match results feed back into the calculation of subsequent expected goals (λ), and each week these noisy current-season averages are blended with last season’s stats. This repeated averaging pulls temporary leads or deficits toward the league mean, reducing persistent differences between strong and weak teams. This feedback loop compressed variation across simulated seasons, causing title probabilities to bunch up, making the league appear artificially balanced compared with a static model where team strengths remain fixed. Perhaps with a bit more time I could develop a dynamic approach that improves on the current method, but for now the fixed λ approach appears to generate a better approximation to reality.

Last word

Applying statistical methods to football outcomes is both fascinating and practically valuable because it allows us to move beyond intuition and anecdote, quantifying the uncertainty inherent in each match and across an entire season. By modelling goals, team strengths and dynamic interactions, we can simulate outcomes that would be impossible to assess reliably by eye. This not only deepens our understanding of the game’s underlying patterns but also provides actionable insights for analysts, coaches and fans. It illustrates how a combination of mathematics, probability, and real-world data can illuminate the complex, dynamic and often unpredictable world of football. This approach is not limited to football: the same principles can be applied to virtually any competitive or stochastic system where outcomes depend on multiple interacting factors, from other sports to business forecasting, financial markets or epidemiology. In all these contexts, statistical modelling enables a deeper understanding of underlying patterns, informs decision-making and helps anticipate outcomes in complex and uncertain environments. Just don’t assume that my model is going to make you rich.


[1] Geroski, P. A. and A. Jacquemin (1984) ‘Dominant firms and their alleged decline’, International Journal of Industrial Organization (2) 1, pp. 1-27

[2] The Poisson distribution – a probability distribution that describes discrete events – is commonly applied in football analytics to model and predict match outcomes because goals in a match can be thought of as rare, discrete events that occur independently over time. In this framework, each team is assumed to score goals at a constant average rate (λ), and the Poisson distribution gives the probability of scoring exactly 0, 1, 2, … goals in a match. The probability mass function for a variable following the Poisson distribution is defined as  where X is the number of goals a team scores in a match and k is  a specific outcome (a non-negative integer: 0, 1, 2, …). For example, k=2 means “the team scores exactly 2 goals.

[3] Dixon, M. J. and S. G. Coles (1997) ‘Modelling Association Football Scores and Inefficiencies in the Football Betting Market’ Journal of the Royal Statistical Society Series C: Applied Statistics, Volume 46, Issue 2, 265–280