Unveiling True Talent: The Soccer Factor Model for Skill Evaluation

TL;DR

This paper introduces the Soccer Factor Model (SFM), a novel method to accurately evaluate soccer players' true skills by accounting for team influence, supported by extensive data and outperforming benchmarks in predictive accuracy.

Contribution

The paper presents the SFM, a new model that isolates individual player skill from team effects, along with novel metrics for fair cross-player comparison.

Findings

SFM outperforms benchmarks in forecast accuracy.

Introduces Skill- and Performance Above Replacement metrics.

Provides insights into the GOAT debate using new evaluation methods.

Abstract

Evaluating a soccer player's performance can be challenging due to the high costs and small margins involved in recruitment decisions. Raw observational statistics further complicate an accurate individual skill assessment as they do not abstract from the potentially confounding factor of team strength. We introduce the Soccer Factor Model (SFM), which corrects this bias by isolating a player's true skill from the team's influence. We compile a novel data set, web-scraped from publicly available data sources. Our empirical application draws on information of 144 players, playing a total of over 33,000 matches, in seasons 2000/01 through 2023/24. Not only does the SFM allow for a structural interpretation of a player's skill, but also stands out against more reduced-form benchmarks in terms of forecast accuracy. Moreover, we propose Skill- and Performance Above Replacement as metrics for fair cross-player comparisons. These, for example, allow us to settle the discussion about the GOAT of soccer in the first quarter of the twenty-first century.