The effect of the 50:22 law trial on the Currie Cup and Varsity Cup rugby tournaments between 2021 and 2022

Date
2023-12
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Publisher
Stellenbosch : Stellenbosch University
Abstract
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.
AFRIKAANSE OPSOMMING: Taktiese skopwerk is ’n fundamentele aspek van rugby, wat 'n strategiese rol in aanval en verdediging speel, en dra by tot die sukses van 'n span. Die 50:22-reël is ingestel met die doel om verdedigende spanne te dwing om spelers in die agterveld te posisioneer om skoppe teen te werk, en sodoende die aantal spelers in die verdedigende lyn te verminder en die lynspoed tydens kontak situasies te verlaag, wat die risiko van beserings mag verminder. Tot op hede is die huidige studie die eerste om die 50:22-reëlverandering te ondersoek en te vergelyk om die effek van die reëlverandering op taktiese skoppe gedurende ’n wedstryd te assesseer. Hierdie tesis volg ’n artikelformaat waarin een navorsingsartikel (Hoofstuk Vier) saamgestel is. Die doel van die navorsingsartikel was om die effek van die 50:22-reëlveranderinge op rugby-unie skop-profiele op provinsiale- en universiteitvlakke te ondersoek en te vergelyk tussen die 2021 en 2022 toernooie. Hierdie studie het ’n beskrywende retrospektiewe navorsingsontwerp gebruik, waarby video-gebaseerde prestasie-analise (Nacsport Scout Plus) vir data-insameling gebruik is. Die aanvanklike prestasie-aanwysers en hul definisies is bepaal deur gepubliseerde studies, en insette van ’n kundige paneel wat die geldigheid en betroubaarheid van die studie verbeter. Die betroubaarheid van die gekodeerde prestasie-aanwysers is geassesseer deur beide intra- en inter-beoordelaar betroubaarheidsmaatreëls met behulp van 'n heranalise metode. Die primêre kodeerder en ’n eksterne kodeerder het onafhanklik 25% (44 wedstryde) van die wedstryde herkodeer. Die Cohen's Kappa Koëffisiënte het uitstekende ooreenstemming vir beide intra-kodeerder (r=0.98) en inter-kodeerder (r=0.97) betroubaarheid getoon. Vir hierdie studie is ’n omvattende analise uitgevoer op al die skoppe van 177 wedstryde gedurende die 2021 en 2022 Currie Beker (CB) en Varsity Beker (VB) rugbytoernooie, wat gelei het tot ’n totaal van 6,479 skoppe oor die twee seisoene ondersoek is. Met betrekking tot die spesifieke toernooie het die CB ’n totaal van 1,497 skoppe in die 2021-seisoen opgelewer, en 1,628 in 2022. Aan die ander kant het die VB onderskeidelik 1,881 skoppe in 2021 en 1,437 in 2022 opgelewer. In 2022 was daar 53 suksesvolle 50:22 skoppe, 30 in die CB en 23 in die VB. Dit kom neer op minder as een suksesvolle 50:22 skop per wedstryd. Die resultate dui daarop dat die 50:22-reël wel 'n invloed gehad het op die skop-profiel van provinsiale- en universiteitvlak rugby in Suid-Afrika. Wanneer beide toernooie gekombineer word, het die resultate ’n beduidende toename in skoppe deur skrumskakels (p < 0.001) en boks skoppe (p = 0.03) in 2022 in vergelyking met 2021 getoon. Dit stem ooreen met die neiging wat in moderne rugby in vorige studies waargeneem is. Daar was ’n beduidende afname in skoppe deur losskakels (p = 0.01), heelagters (p = 0.01), en skoppe wat plaasvind nadat n’ skop ontvang is (p = 0.01). Die afname in skoppe deur heelagters is waarskynlik takties omdat spanne ekstra spelers agter ingespan het om die 50:22-skop teen te werk, wat sodoende teenaanval geleenthede bevorder. Die resultate van die CB het ’n toename in skoppe deur skrumskakels (p = 0.01) en binne senters (p < 0.001) getoon. Hierdie resultaat, tesame met die afname in skoppe deur losskakels (p < 0.001), dui daarop dat spanne op professionele vlak die verantwoordelikheid van skoppe meer verdeel. Die studie het ’n toename in hoog skoppe (p = 0.01) getoon, moontlik as gevolg van die feit dat ’n 50:22-skop 'n langer tipe skop benodig. Die VB-resultate het ’n beduidende afname in die hoog skoppe getoon, waarskynlik as gevolg van addisionele spasie in die verdedigende lyn, wat spanne aanmoedig om met die bal te hardloop. ’n Afname in skoppe in die tweede kwart (p = 0.02) en ’n toename in die vierde kwart (p = 0.01) is waargeneem. Dit kan moontlik wees dat spanne die 50:22-skop as ’n aanvallende opsie gebruik. Wanneer die 2022-seisoen van die CB en VB vergelyk word, het die resultate getoon dat skrumskakels beduidend meer skop (p < 0.001) en losskakels beduidend minder skop (p < 0.001) in die CB as in die VB. Die VB het die hoog skoppe beduidend meer gebruik (p < 0.001) as die CB, terwyl die CB beduidend meer kompeteerbare skoppe (p < 0.001) gebruik het. Die bevindinge verdiep en versterk ons begrip van hoe die 50:22-reël die gebruik van skopstrategieë deur spanne tydens die wedstryd beïnvloed. Hierdie studie bied waardevolle insigte vir afrigters, prestasie-analiste en spelers in hul voorbereiding en gebruik van hierdie reël in hul skopstrategie.
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Thesis (M Sport Sc)--Stellenbosch University, 2023.
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