Detecting individual preferences and erroneous verdicts in mixed martial arts judging using Bayesian hierarchical models

• Published in: European journal of operational research Vol. 312; no. 2; pp. 733 - 745
• Main Authors: Holmes, Benjamin, McHale, Ian G., Żychaluk, Kamila
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.01.2024
• Subjects: Bayesian statistics; Biases; Hierarchical model; Mixed martial arts; OR in sports; Mixed martial arts; Hierarchical model; Biases; OR in sports; Bayesian statistics
• ISSN: 0377-2217; 1872-6860
• DOI: 10.1016/j.ejor.2023.07.004

•Individual preferences exist within Mixed Martial Arts judging.•Judges’ preferences may determine the outcome of a contest.•Judges appear to be influenced by a home crowd and exhibit reputation bias.•Fans appear to be less influenced by variables indicative of bias.•Statistical models can determine whether a judge’s score was controversial. In this paper, we use Bayesian hierarchical models to investigate the decision-making of judges of mixed martial arts (MMA) contests. Whilst there has been research into the judging of various sports in the past, none have explicitly modelled the judges’ behaviours at an individual level. We progress the literature by demonstrating that judges have personal preferences towards the different actions that they must assess during a fight. The preferences themselves may be the deciding factor in a bout, as demonstrated using a historical case study. We apply the concept of variable significance to the predictions of scores, to assess whether a judge’s verdict was within reason. Finally, we develop a model that predicts a bout’s fair outcome, which could be used in various ways in MMA.