Browsing by Author "Strydom, Wikus"

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    The effect of the 50:22 law trial on the Currie Cup and Varsity Cup rugby tournaments between 2021 and 2022
    (Stellenbosch : Stellenbosch University, 2023-12) Strydom, Wikus; Kraak, Wilbur; Vaz, Luiz; Tucker, Ross; Stellenbosch University. Faculty of Medical and Health Sciences. Dept. of Exercise, Sport and Lifestyle Medication
    ENGLISH ABSTRACT: Tactical kicking is a fundamental aspect of rugby union “rugby”, playing a strategic role in attack and defence, contributing to the success of a team. The 50:22 law was implemented with the aim of compelling defending teams to drop players into the backfield to cover the kick, thereby reducing the number of players in the defensive line and decreasing the line speed during contact situations, lowering the risk of injuries. To the investigators knowledge, the current study was the first to investigate and compare the 50:22 law change to assess the effect of the law change on tactical kicking during match-play. This thesis followed an article format where one research article (Chapter Four) was compiled. The research article aimed to investigate and compare the effect of the 50:22 law changes on rugby union kicking profiles at provincial and university levels between the 2021 and 2022 tournaments. This study employed a descriptive retrospective research design, utilising video-based performance analysis (Nacsport Scout Plus) for data collection. The initial performance indicators and their operational definitions were established using published peer-reviewed studies, and input from an expert panel further validated and enhanced the relevance and comprehensiveness. For reliability of the coded performance indicators, the primary investigator, and an external coder independently re-coded 25% (44 matches) of the matches. The resulting Cohen's Kappa Coefficients demonstrated very good agreement for both intra-coder (r=0.98) and inter-coder (r=0.97) reliability. For this study, a comprehensive analysis was conducted on all the kicks from 177 matches during the 2021 and 2022 Currie Cup (CC) and Varsity Cup (VC) rugby tournaments, resulting in a total of 6,479 kicks being examined across the two seasons. When considering the specific tournaments, the CC yielded a total of 1,497 kicks in the 2021 season, and 1,628 in 2022. On the other hand, the VC produced 1,881 kicks during 2021, and 1,437 in 2022. In 2022, there were 53 successful 50:22 kicks, 30 in the CC and 23 in the VC. That equals to less than one successful 50:22 kick per match. The results indicate that the implemented 50:22 law influence the kicking profile at provincial and university level rugby in South Africa. When combining both tournaments, the results revealed a significant increase in the number of kicks by scrum halves (p < 0.001) and box kicks (p = 0.03) in 2022 compared to 2021. This aligns with the trend that has been seen in modern rugby in previous studies. There was a significant decrease in the number of kicks by flyhalves (p = 0.01), fullbacks (p = 0.01), and kicks that took place from a received kick (p = 0.01). The decrease in the number of kicks by fullbacks and from received kicks are likely due to teams deploying additional backfield players to counter the 50:22 kick, thereby enhancing counter-attacking opportunities upon receiving kicks. The results of the CC revealed an increase in the percentage of kicks by scrum halves (p = 0.01) and inside centres (p < 0.001). This result, together with the decrease in the number of kicks by fly halves (p < 0.001), suggests that teams at the professional level, distribute the responsibility of kicking more amongst the backline players. The study showed an increase in punt kicks (p = 0.01), likely due to a 50:22 kick needing a longer type of kick. The VC results revealed a significant decrease in the number of kicks, likely due to additional space in the defensive line, encouraging teams to run with the ball. A decrease in the number of kicks in the second quarter (p = 0.02) and an increase in the percentage of kicks in the fourth quarter (p = 0.01) was observed. This could possibly be due to teams using the 50:22 kick as an attacking option. When comparing the 2022 season of the CC and VC, the results revealed that scrum halves kick significantly more (p < 0.001) and flyhalves significantly less (p < 0.001) in the CC compared to VC. The VC used the punt kick significantly more (p < 0.001) compared to the CC, whereas the CC used contestable kicks (p < 0.001) significantly more. The findings deepen our understanding of how the 50:22 law influences how teams’ utilise kicking strategies during the match. This study provides valuable insights to coaches, performance analysts, and players in their preparation and utilisation of this law in their kicking strategy.