Comparative analysis of tackle performance between Northern and Southern hemispheres in elite rugby union

Abstract

The aim of this study was to compare defensive differences between elite Northern and Southern hemisphere nations, using in-depth and specific performance indicators. There has long been a perception that Southern hemisphere nations have an ascendancy over those from the North, especially as the Northern hemisphere have just one world cup win out of a possible seven. This study therefore aimed to determine if tackle performance differed between hemispheres or whether the Southern dominance was because of other factors. The study analysed games from the Six Nations (n=10) and Rugby Championships (n=12) as these competitions contained the top nine countries in the world therefore the quality of opposition and match importance was high. In-depth performance indicators were developed and match events were analysed fully, phase-by-phase, using the software Sportscode Elite (version 8.4.1). Intra-observer reliability was tested and a kappa value of 0.8 or above was deemed as acceptable and this was achieved. Data was analysed within Microsoft Excel (2011) and then ranked in IBM SPSS. Several significant differences (p<0.05) were found between hemispheres. The Northern hemisphere made more tackles and had a significantly greater tackle completion and missed significantly fewer tackles than the Southern hemisphere. More positive tackles were made in the Southern hemisphere however more effective tackles were made in the North. Other significant differences were found regarding the success of back three tackles, the height and height effectiveness of tackles and the outcomes. It was concluded that tackle performance between hemispheres were similar however there were some differences that may explain why the Southern hemisphere have been dominant in recent years. Although the North had a greater tackle completion and fewer missed tackles, the Southern hemisphere were more effective in other areas. They defended the wider channels better and tackled high more frequently which was shown to be more effective. The Southern hemisphere were also better at gaining positive outcomes from jackal attempts, which combined with the aforementioned factors could explain why the South have had an ascendancy and could help to predict the outcomes of future matches.