Exploring the effect of various match factors on team playing styles in the National Rugby League

Objectives This study examined the effect of match location, score-line, team quality and match outcome on the expression of team playing styles in the National Rugby League (NRL) across the 2015-2019 seasons. Methods Thirty-eight performance indicators (e.g. offloads, runs) from all NRL games (n = 2010) were collected. Match-related factors examined were location (home/away/neutral), match type (absolute score differential), team quality (end of season ladder position) and outcome (win/draw/loss). Factor analysis using principal component analysis (PCA) were run to identify team playing styles, which were inferred from the clustered dimensions (Factors) of team performance indicators. Discriminant analysis was then used to determine the effect of the match factors on team playing styles. Results PCA revealed nine Factors accounting for similar to 54% of team performance variance. Discriminant analysis did not meaningfully resolve team playing styles for match type, team quality or location (similar to 34%, similar to 46% and similar to 58% classification accuracy, respectively). One discriminant function correctly classified similar to 81% of matches based on outcome, including four team playing styles defined as 'attacking play', 'linebreaks', 'handling errors' and 'conceded linebreaks'. Conclusions Team playing styles characterised by 'attacking play' and 'linebreaks', coupled with relative defensive efficiency showed the greatest association with winning regardless of team quality, match location or match type. Using similar sport analytical techniques, additional insight into the importance of various team playing styles over the time-course of a match may allow teams to further extrapolate the likelihood of success in real-time.