Technical determinants of tackle and ruck performance in International Rugby Sevens.

Abstract Rugby Sevens ('Sevens') is one of the fastest growing sports in the world. This growth was marked by the inclusion of the sport in the Olympic Games in 2016. The most frequently occurring contact events in Sevens are the tackle and ruck. Performing specific techniques during these contact events can reduce the risk of injury and increase the likelihood of success. Therefore, the purpose of this study was to identify the technical determinants associated with tackle and ruck performance outcomes in Sevens. A total of 4799 tackles and 1405 rucks from the 2014/2015 HSBC Sevens World Series were coded for contact, post-contact, ruck, match contextual variables and outcomes. Relative risk ratio (RR), the ratio of the probability of an outcome occurring when a variable was observed, was determined using multinomial logistic regression. A moderate ball-carrier leg drive reduced the probability of losing possession by 25% (RR 0.75, 95% CI, 0.58-0.97, p < .05). Conversely, ball-carriers had a 53% higher likelihood of losing possession when the tackler executed a moderate leg drive (RR 1.53, 95% CI, 1.09-2.14, p ≤ .05). Maintaining possession at the ruck was more likely to occur when committing one attacker compared to two (RR 0.31, 95% CI, 0.19-0.49, p < .001). Active ball-carrier placement also increased the likelihood of maintaining possession at the ruck (RR 14.67, 95% CI, 9.55-22.56, p < .001). Sevens coaches and trainers can now positively design evidence-based technical training programmes and emphasise specific tackle techniques in training using data from Sevens video analysis. Also, given that this is the first study to relate tackle technical determinants to an outcome (i.e. the first 'how' study) in Sevens, this work provides the foundation for similar Sevens video analysis studies in the future.

Technical determinants of tackle and ruck performance in International rugby union.

The most frequently occurring contact events in rugby union are the tackle and ruck. The ability repeatedly to engage and win the tackle and ruck has been associated with team success. To win the tackle and ruck, players have to perform specific techniques. These techniques have not been studied at the highest level of rugby union. Therefore, the purpose of this study was to identify technical determinants of tackle and ruck performance at the highest level of rugby union. A total of 4479 tackle and 2914 ruck events were coded for the Six Nations and Championship competitions. Relative risk ratio (RR), the ratio of the probability of an outcome occurring when a characteristic was observed (versus the non-observed characteristic), was determined using multinomial logistic regression. Executing front-on tackles reduced the likelihood of offloads and tackle breaks in both competitions (Six Nations RR 3.0 Behind tackle, 95% confidence interval [95% CI]: 1.9-4.6, effect size [ES] = large, P < 0.001); Championship RR 2.9 Jersey tackle, 95% CI: 1.3-6.4, ES = moderate, P = 0.01). Fending during contact increased the chances of offloading and breaking the tackle in both competitions (Six Nations RR 4.5 Strong, 95% CI: 2.2-9.2, ES = large, P = P < 0.001; Championship RR 5.1 Moderate, 95% CI: 3.5-7.4, ES = large, P < 0.001). For the ruck, actively placing the ball increased the probability of maintaining possession (Six Nations RR 2.2, 95% CI: 1.1-4.3, ES = moderate, P = 0.03); Championship RR 4.0, 95% CI: 1.3-11.8, ES = large, P = 0.01). The techniques identified in this study should be incorporated and emphasised during training to prepare players for competition. Furthermore, these techniques need to be added to coaching manuals for the tackle and ruck.