Let Them Be the Judge of That: Bias Cascade in Elite Dressage Judging

SIMPLE SUMMARY: Most aesthetic sports where judges subjectively rate performances can suffer from issues like systematic errors due to biases. Equestrian dressage is defined through the intricate interaction between horse and rider. Assessing these interactions can be particularly complex, often exceeding human processing capabilities. The study focuses on whether the current dressage system predisposes international judges to using biases, and inadvertently favours certain horse-rider combinations. The study examined 510 judging scores, gathered from seven elite-level dressage competitions held between May 2022 and April 2023. The effect of different factors, such as whether riders competed in their home country, if they had the same nationality as the judges, their starting order during the competition, and how they were ranked according to previous performances were analysed. Results showed that all these factors influence the final dressage results. In order to assist judges in providing objective, transparent scores, a clear evidence-based set of judging guidelines should be developed, which would prevent judges from having to resort to cognitive short cuts. That way, the complexity of judging is reduced, making scores more objective, transparent and fair. ABSTRACT: Sport performances judged subjectively often suffer from systematic errors due to biases, with the sport of equestrian dressage being no exception. This study examines whether international dressage judges display systematic errors while evaluating elite horse-rider combinations. Data from seven 5* Grand Prix dressage events between May 2022 and April 2023 were analyzed (510 judges’ scores) using Multivariable Linear Regression Analysis. Five predictor variables—Home, Same Nationality, Compatriot, FEI Ranking and Starting Order—were studied in relation to Total Dressage Score (TS). The model accounted for 44.1% of TS variance; FEI Ranking, Starting Order, Compatriot, Same Nationality, and Home were statistically significant (p < 0.001). Judges exhibited nationalistic and patriotism-by-proxy biases, awarding significantly higher scores to riders from their countries (p < 0.001). FEI Ranking and Starting Order also influenced scores significantly (p < 0.001). These biases, combined, created a cascade effect benefiting a specific group of riders. To address this, measures should be taken to develop a more objective judging system that is based on unequivocal, transparent and evidence-based criteria and supports the continuous development of a fair, sustainable, equine welfare orientated sport that fosters societal acceptance,