Second-leg home advantage no more? The impact of video assistant referee and no away goals rule in elite soccer

Does hosting the return leg in two-legged soccer ties improve a team’s advancement chances, as some contend, or is this perceived second-leg home advantage merely an illusion, as others argue? This question of competitive fairness is increasingly pertinent in today’s high-stakes soccer environment. While a definitive answer remains elusive, recent rule changes in European soccer, namely the introduction of the video assistant referee (VAR) system and the abolition of the away goals rule (AGR), have added new complexities. Analyzing 906 UEFA Champions League ties (2000/01–2023/24) via weighted logistic regression with robustness checks and team strength controls, we find that a modest second-leg home advantage appears only when AGR is in effect without VAR. Introducing VAR alongside AGR seemingly reverses that advantage, albeit lacking robustness, while neither rule alone nor both absent yields an order effect. Notably, VAR offsets the second-leg home advantage solely in AGR’s presence, while AGR creates that advantage solely in VAR’s absence. Although team quality remains the primary driver of success, these findings illustrate how seemingly innocuous regulatory shifts can redefine competitive fairness. Our results thus offer timely insights for policymakers aiming to design fair and strategically engaging formats in elite European soccer, particularly given the dearth of research on the subject.