The Impact of Foreign Players in the English Premier League: A Mathematical Analys

TL;DR

This study analyzes English Premier League data from 2009/10 to 2017/18 to identify key financial and player composition factors influencing team performance, using statistical and machine learning methods.

Contribution

It introduces a comprehensive analysis of resource distribution and player nationality impact on team success, employing alternative league rankings and PCA.

Findings

Top teams have higher overall expenditure and foreign player ratios.

Resource inequality among clubs is significant, shown by Lorenz curves.

Performance does not necessarily correlate with financial profit.

Abstract

We undertake extensive analysis of English Premier League data over the period 2009/10 to 2017/18 to identify and rank key factors affecting the economic and footballing performances of the teams. Alternative end-of-season league tables are generated by re-ranking the teams based on five different descriptors - total expenditure, total funds spent on players, total funds spent on foreign players, the ratio of foreign to British players and the overall profit. The unequal distribution of resources and expenditure between the clubs is analyzed through Lorenz curves. A comparative analysis of the differences between the alternative tables and the conventional end-of-season league table establishes the most likely factors to influence the performances of the teams that we also rank using Principal Component Analysis. We find that the top teams in the league are also those that tend to have the highest expenditure overall, for all players, including foreign players; they also have the highest ratios of foreign to British players. Our statistical and machine learning study also indicates that successful performance on the field may not guarantee healthy profits at the end of the season.