Analysis of styles of play according to season and end of season rank in the National Rugby League

Objectives: This study aimed to identify styles of play in the National Rugby League (NRL) relative to season and end of season rank (position on the NRL ladder) across the 2015-2019 seasons. Design: Retrospective, longitudinal analysis of performance indicators. Methods: Forty-eight performance indicators (e.g. runs, tackles) from all NRL teams and matches during the 2015-2019 seasons (n = 2010) were quantified. Principal component analysis (PCA) was then used to identify styles of play based on dimensions (Factors) of performance indicators. Multivariate analysis of covariance (MANCOVA) was then used to explain these emergent styles of play relative to 'season' and 'end of season rank'. Results: The PCA revealed nine Factors (six attacking, two defensive and one contested style) accounting for similar to 51% of seasonal team performance variance. These nine Factors differed across 'seasons', with four showing an effect against 'end of season rank'. From these four, two Factors (ball possession and player efforts) impacted upon the combined effects of 'season' and 'end of season rank'. Conclusions: The PCA identified nine Factors reflecting a spread of attacking, defensive and contested styles of play within the NRL. These styles differed relative to season and a team's end of season ranking. These results may assist practitioners with the recognition of more contemporary styles of play in the NRL, enabling the development of strategies to exploit competition trends. (C) 2020 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study identified nine factors reflecting different attacking, defensive, and contested styles of play in the NRL, which varied across seasons and end of season rankings. Of these factors, ball possession and player efforts were found to impact the combined effects of season and end of season rank.