Two related studies compared the consistency of two different methods of interpreting and applying scoring criteria in Muay Thai that are normally used by officials in the UK and that are used by officials in Thailand. In the first study, levels of consistency were determined by comparing judge's scores (n=270) from forty-five bouts judged by UK officials and forty-five judged by Thai officials. In the second study the original forty-five bouts judged by UK judges were compared with forty–five bouts judged by UK officials using Thai judging criteria. Consistency was examined in both studies using two methods. The first method compared differences in the range of the highest vs. lowest points awarded by judges for each bout. The second method compared homogeneity of variance between judges' scores. Results suggested that the Thai officials were more consistent than their UK trained counterparts but also that UK judges were more consistent when adopting the Thai judging criteria. It was suggested that the use of very clearly defined criteria and concrete operationalization of otherwise subjective concepts used in applying the system used in Thailand was the main reason for the findings.