Within and Between-Tournament Variability in Equestrian Polo.

The external work, as measured by global positioning systems, undertaken by Polo ponies during tournament play has been well-described across Polo of varying levels in both Open and Women's Polo. However, the variability within these data have not been thoroughly examined. Understanding the variability within these data between players (within-tournament variability) and between tournaments allows a deeper understanding of expected Polo performance and can inform coaching and tactical decisions, as well as aid in longitudinal horse development and comparison to other equestrian disciplines. The present paper captured data from 618 chukkas of Polo, in levels ranging from 0- to 16-goal and Women's Polo, across three New Zealand Polo seasons. Standard error and coefficient of variation were calculated to assess within-tournament variability; between-tournament variability was assessed via median percentage difference and Spearman's rho correlation coefficients. Playing duration, speeds (average and maximum) and distance metrics (total and standardized speed zones) typically increase with level of Polo play, with a concomitant reduction in within-tournament variability also seen. Nought (0-), 6-goal and Women's Polo show comparable within-tournament measures and associated variability. Polo, shows a high degree of between-tournament variability as within-player variability often exceeds that of between-player variability, affecting mathematical interpretations of reliability. Z-scores are a convenient alternative method for capturing and displaying between-tournament variability for the examined parameters, facilitating comparing across tournaments and seasons. Exemplar boundaries for this approach in Polo are provided.