Did technology break the game? Effects of the video assistant referee (VAR) on elite European soccer

The addition of the video assistant referee (VAR) arguably represents the most significant change in the recent history of professional soccer. In this paper, we investigate whether the VAR has affected game play in elite European soccer by examining trends in match statistics that make up the typical box score. We use data from more than 15,000 matches, equally split between the pre- and post-VAR periods, played in the top flights of the four major European leagues. In addition to standard analysis of variance, which has typically been used in previous studies, we present results from causal difference-in-differences (DID) estimations that exploit the variation in the implementation timing of the VAR across the leagues for identification. The results indicate that among ten match statistics, the only robust change involved offsides, which decreased in the post-VAR period by 0.5–1.2 per match. For the other statistics, the estimated impact of the VAR is not statistically significant or robust across estimators and leagues. We conclude that the VAR, by and large, does not impact basic game play in professional soccer. • We examine the impact of the VAR on basic game play in elite European soccer. • Staggered implementation of the VAR across leagues is utilized to estimate causal effects. • Only one box score variable – offsides – showed a statistically significant and robust change pre- to post-VAR. • We conclude that the VAR does not fundamentally change basic game play in elite soccer.