Dealing With Randomness in Match Outcomes: How to Rethink Performance Evaluation in European Club Football Using Expected Goals

Abstract

In European club football, decision makers often rely on recent match outcomes when evaluating team performance, even though short-term results are heavily influenced by randomness. This can lead to systematic misjudgments. In this article, we propose a complementary approach for performance evaluation. We build upon the concept of expected goals based on quantified scoring chances and develop a chart that visualizes situations in which a team’s true performance likely deviates from the performance indicated by match outcomes. This should prevent clubs from making flawed decisions when match outcomes are misleading due to the influence of random forces.