Changes in player characteristics and match activities in Bledisloe Cup rugby union from 1972 to 2004.

To illustrate changes in elite rugby union match activities, we analysed coded videotape recordings of the first match in each Bledisloe Cup series played between Australia and New Zealand from 1972 to 2004. We also analysed the stature and body mass of players. Effects associated with professionalism, weather conditions, and time (expressed as change per decade) were estimated with a simple generalized linear model and standardized for interpretation of magnitude. The sample size permitted confident conclusions about effects that were of at least moderate magnitude (standardized mean difference >0.6). Increases in passes, tackles, rucks, tries, and ball-in-play time were associated with the advent of professionalism, whereas there were reductions in the numbers of lineouts, mauls, kicks in play, and in mean participation time per player. Noteworthy time trends were an increase in the number of rucks and a decrease in the number of scrums. Good weather conditions were associated with increases in tries and points scored and with reductions in the number of kicks in play and participation time per player. With the advent of professionalism, players have become heavier and backs have become taller. Overall, there have been major changes in international rugby match activities and player size over the past three decades. We believe law changes and developments in match analysis, equipment technology, and player training have contributed to the changes associated with the introduction of professionalism.