Evolution of game-play in the Australian Football League from 2001 to 2015

This study investigated the evolution of game-play manifested via team performance indicator characteristics in the Australian Football League (AFL) from the 2001 to 2015 seasons. The mean values for 18 performance indicators were collated for every AFL team over 15-seasons. A multivariate analysis was used to uncover temporal trends in the dataset. Compared to the 2004 season, the 2005 to 2010 seasons were characterised by large growth in the counts of handballs (d=0.83; 90% CI=0.22-1.43), disposals (d=1.24; 90% CI=0.59-1.87), uncontested possessions (d=1.37; 90% CI=0.71-2.01), clangers (d=2.14; 90% CI=1.39-2.86) and marks (d=1.43; 90% CI=0.76-2.07). Contrastingly, the effective disposal percentage declined rapidly during the same period. The number of inside 50m counts remained stable throughout the 15-season period. The ordination plot of league-wide performance indicator characteristics illustrated a distinct cluster from the 2001 to 2004 seasons, an abrupt shift from the 2005 to 2009 seasons, and an emergent (re)stabilisation from the 2010 to 2015 seasons. The results demonstrate the synchronous league-wide evolution of game-play in the AFL from the 2001 to 2015 seasons. Amongst other constituents, this evolution likely reflects the introduction of modernised coaching strategies, rule changes and changing perceptions of rule interpretations.