Category: Match Statistics
Rugby Science Update 10
Predicting performance at the group-phase and knockout-phase of the 2015 Rugby World Cup
The objective of this study was to develop a predictive model for performance during the group-phase of the 2015 Rugby World Cup (RWC) and to determine the most significant and relevant performance indicators for predicting match outcome. Performance indicators were downloaded from the OPTA website from the 2015 RWC (40 group-phase and 8 knockout-phase matches) to be analysed. A random forest classification model was developed to establish the relationship between the performance indicators and the match outcomes. The model created using the group-phase matches achieved a 100% accuracy of predicting match outcomes. When applied to the knockout-phase matches, this model had an overall accuracy of 87.5%, with sensitivity and specificity of 87.5%. The model identified 13 performance indicators that significantly predicted match outcomes. These included tackle-ratio, clean breaks, average carry, lineouts won, penalties conceded, missed tackles, lineouts won in the opposition 22, defenders beaten, metres carried, kicks from hand, lineout success, penalties in opposition 22 m and scrums won. The performance indicators in the group-phase matches that could predict the match outcomes were tackle ratio, clean breaks and average carry. Interestingly, the performance indicators do not change from the group to knockout stages. The findings of this study provide insights for rugby teams to assess their performance and understand the major technical factors contributing to success and failure in individual matches. Coaches and sport practitioners can then adjust their technical and tactical training appropriately.
This study is published in European Journal of Sport Science.
Statistical Review and Match Analysis of Rugby World Cups Finals
The purpose of this study was to describe game statistics and match analysis of Rugby World Cups from 1987 to 2015. The analysis focused on all final matches (n = 8) from 1987 to 2015 Rugby World Cups, and official reports from the Rugby World Cup webpages were also included in the analysis. This analysis included tracking counts of all match activities. 39 key performance indicators were categorised into seven groups: mode of scoring, set-pieces, defensive, offensive, infringements, replacements, and team/time possession efficiency. It was observed that the winning teams of the final matches in the Rugby World Cup attempted more penalty kicks. Interesting, the number of drop goals were similar between the winning and losing teams. The winning teams won more set pieces, including winning scrums and lineouts. In the defensive category, the winning teams attempted and completed more tackles than the losing teams. Regarding, the offensive category, the winning teams passed less, completed fewer offloads, and were involved in more rucks and mauls. Interestingly, it was noted that the losing teams made more substitutions than the winning teams. Furthermore, both teams in the Rugby World Cup finals shared similar possession of the ball. The authors of the study mentioned the importance of player emotions, as well as conducting more in-depth match analysis to enhance team performance characteristics.
This study is published in Journal of Human Kinetics.
How to harness and improve on video analysis for youth rugby player safety: a narrative review
The purpose of this narrative review is to synthesize the strengths and limitations of video analysis in youth rugby used for injury surveillance, highlight the importance of video analysis for youth player safety and discuss recommendations. This review highlights multiple strengths and limitations of video analysis in youth rugby for injury surveillance. It is recommended in this review that video assessment of injury and concussion outcomes be prioritised to educate, inform and improve youth rugby safety. The importance of analysing these outcomes is highlighted within this review which develops and guides targeted injury and concussion prevention strategies. Furthermore, a video analysis framework consensus that is specific to youth rugby is needed.
This study is published in BMJ Open Sport & Exercise Medicine.
Rugby Science Update 6
The role of player mass and contact speed on head kinematics and neck dynamics in rugby union tackling
This study aimed to use multi- body modeling simulations to examine how tackler and ball carrier mass and contact speed affect inertial head kinematics and neck dynamics. Simulations were run by independently varying the ball carrier and tackler mass (from 60 to 110kg) and speed (from 0 to 10 m/s). Peak resultant inertial neck dynamics (force and moment) and head kinematics (linear acceleration, angular acceleration, and angular velocity) were extracted from each simulation. The study found that the greatest inertial head kinematics and neck dynamics were sustained by a lighter player during a tackle with a heavier player, irrespective of their role as a tackler or ball carrier. For contact speed, the greatest inertial head kinematics and neck dynamics sustained by the ball carrier and tackler were when they were both traveling at the highest speed.
This study was published in the Scandinavian Journal of Medicine & Science in Sports.
Tackle technique and changes in Playerload™ during a simulated tackle: an exploratory study
The aim of this study was to explore how PlayerLoad™ changes between different levels of tackling technique during a simulated tackle. PlayerLoad™ did not significantly differ between technical score categories at the point of contact. However, during the tackle completion phase, tackles within the high technical scoring category recorded a higher PlayerLoadTM than low and medium technical scoring tackles. The PlayerLoad™ trace of tackles within the high technical scoring category were also more consistent throughout the tackle. The variability in the PlayerLoad™ trace may be the consequence of players not shortening their steps before contact, reducing their ability to control their movement during the contact and post-contact phase of the tackle. Using the PlayerLoad™ trace in conjunction with technique assessments offers coaches and practitioners insight into the physical-technical relationship of each tackle to optimise tackle skill training, monitoring and match preparation.
This study was published in the Journal of Sports Science and Medicine and free to download.
Three-dimensional mechanics of the rugby tackle, does the ball carrier alter their movement into contact in response to the tackler’s position?
The aim of this exploratory study was to identify if, when, and how, the ball carrier modified their motion when being tackled, in response to specific tackle instructions given to the tackler. The ball carrier was observed to modify their behaviour in response to anticipated changes in the tackler’s motion. Specifically, the ball carrier positioned their body at contact using one of two movement strategies: (1) increasing their stability via flexing their trunk, knee, and hips more when entering mid or high trunk tackles; or (2) offload the ball or perform an evasive movement strategy by positioning themselves in a more upright body position when being tackled at a low trunk tackle height. These findings, together with knowledge of tackle injury-risk factors, could inform future coaching interventions for the ball carrier to optimise their performance and mitigate injury risk during the tackle.
This study was published in the International Journal of Sports Science and Coaching and is free to access.
Rugby Science Update 1
The impact of matches and travel on rugby players’ sleep, wellness and training
The purpose of this study was to determine the influence of trans-meridian travel and matches on the sleep, wellness, and training of players from four Super Rugby teams during the 2017 Super Rugby season. Travel was associated with substantial sleep deprivation for three of the teams when overseas, which can be explained by travel fatigue, jet lag and a disruption of the normal sleep habit (sleeping in a non-familiar environment and sharing room with a team-mate). The findings of this research suggest that players in four Super Rugby players suffer reduced wellness and an overall sleep deficit when they travel overseas. As trans-meridian travel appears to affect players’ sleep, teams should implement strategies such as melatonin supplementation and light exposure to reduce the effect of jet lag. A correct sleep hygiene could also help players in catching up with the sleep loss they may experience throughout the season and following travel. As there was some evidence of substantial individual responses, teams should carefully monitor the sleep of their players with particular attention to those who sleep more than average, as they may suffer more sleep disruption.
Training load, injury burden, and team success in professional rugby union: risk versus reward
The purpose of this study was to establish whether associations among training load, injury burden, and performance exist within rugby. The study found injury burden was negatively associated with performance, whereas training load measures displayed only trivial associations with performance.
Physical characteristics of different professional rugby union competition levels
The purpose of this study was to evaluate whether differences in physical characteristics (running-related and collision-related) derived from microsensor technology exist between four different professional rugby union competition levels. The study found collisions per minute, Collision Load™ per minute and High Metabolic Load Efforts per minute were all higher during International Rugby and European Rugby Champions Cup match-play, when compared to PRO14 and British and Irish Cup match-play. Distance per minute and High-Speed Running distance per minute were lower during International Rugby and European Rugby Champions Cup match-play, when compared with PRO14 and British and Irish Cup match-play. Our data suggest that rugby union players require specific physical preparation for different levels of competition. In particular, players may need specific preparation for higher collision demands at higher levels of competition.
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