Effects of the video assistant referee on games in the Bundesliga

Referees and their assistants are faced with the challenge of making correct decisions in complex and high-speed game situations. Subconscious bias on the part of referees and the resulting systematic favouring of teams have already been shown many times in sports economics and impair fairness in football. Since the 2017/2018 season, the video assistant referee (VAR) has been used as a technical support for referees to correct clearly incorrect decisions. Based on 2,448 games and 1,880 match situations reviewed by the VAR from the 2019/2020 to 2022/2023 seasons, this study examines whether the VAR is a suitable instrument to counteract the bias of referees on the field. The analyses carried out reveal that the VAR is only able to accomplish this to a limited extent. Even with technical support, human bias remains in the decision-making process.