The effects of situational variables on expected goals: A case study in international football

Background: In the ever-evolving field of football analytics, understanding the factors influencing expected goals is crucial for gaining deeper insights into team performance. The aim of this study was to examine the effects of match conditions on the expected goals (xG) from defensive and offensive points of view in international elite football matches of the Greek national team. Methods: Twenty-four (24) Greek national team matches during the period between 23 March 2019 and 14 November 2021 were analyzed for the study. In these selected matches the Greek national team took 369 shots and conceded 174 shots, out of which scored 26 goals, and conceded 23 goals to their opponents. Results: Our findings suggest that situational variables such as time may influence expected goals (xG). More specifically, the Greek national team obtained higher expected goals for (xGf) during the second half of their matches compared to the first half. Zonal analysis of shots and goals revealed that central areas recorded more shots on goal in the analysis of both Greece and their opponents, but Greece favoured shooting from inside the penalty box more often than their opponents. Conclusion: The findings emphasize the need for match analysts and coaches to consider the impact of situational variables during assessments of data analytics, especially in future xG research.