Research Article, J Athl Enhanc Vol: 13 Issue: 5

Impact of New Rule Changes on Australian Professional Rugby League Match-Play and Wellbeing Statistics-Implications for Training-Program Design

Daniel Ferris^1*, Tim J. Gabbett^2,3, Tim Newans¹, Ryan Simmons⁴ and Clare Minahan¹

¹Department of Sports Science, School of Allied Health Sciences, Griffith University, Gold Coast, Australia

²Department of Sports, Griffith University, Gold Coast, Australia

³Department of Health Innovation, Federation University, Ballarat, Australia

⁴Department of Sports, Federation University, Ballarat, Australia

*Corresponding Author: Daniel Ferris,
Department of Sports Science, School of Allied Health Sciences, Griffith University, Gold Coast, Australia
E-mail:dan.ferris@griffithuni.edu.au

Received date: 08 July, 2024, Manuscript No. JAE-24-141005;

Editor assigned date: 11 July, 2024, PreQC No. JAE-24-141005 (PQ);

Reviewed date: 25 July, 2024, QC No. JAE-24-141005;

Revised date: 01 August, 2024, Manuscript No. JAE-24-141005 (R);

Published date: 08 August, 2024, DOI: 10.4172/2324-9080.1000143

Citation: Ferris D, Gabbett TJ, Newans T, Simmons R, Minahan C (2024) Impact of New Rule Changes on Australian Professional Rugby League Match-Play and Wellbeing Statistics-Implications for Training-Program Design. J Athl Enhanc. 13:5.

Abstract

Keywords: Rugby league; Player well-being; Micro-technology; Game analysis, Rule changes

Introduction

Rugby league is a popular contact sport played predominantly in Australia, New Zealand, and the United Kingdom. The National Rugby League (NRL) is the premier competition for men in Australia with matches comprising two teams competing for 40-min halves separated by a 10-min interval [1-3]. In each team, thirteen players take the field with four interchange players and a maximum of eight player-substitutes per match. Undoubtedly, a rugby league match represents the highest physical demand imposed on athletes in a single week compared with training load [4].

Since season 2020, there have been multiple rule changes to NRL competition matches. Although changes in competition rules are not uncommon in sport, the effects of rule changes on match statistics as well as player performance and wellbeing are rarely investigated [5]. Given the already high physical demand of rugby league on athletes, understanding the effect of rule changes on athletes is important to improve or maintain player performance and wellbeing [6]. Several studies have described the contextual factors affecting the physical and psychological responses to competitive rugby league match- play, including match location, team playing styles, in-game win probabilities and self-reported wellness [7-16]. However, no previous study has investigated individual match performance and self-reported wellness responses since the ‘six-again’ rule that was first introduced during the COVID-19-enforced lockdown allowing a referee to award an attacking side six more tackles for ruck infringements rather than a penalty. This has been reported as one of the most profound rule change since the New South Wales Rugby League introduced the 10-m defensive rule in 1993 [17,18]. Previous rules indicated that for any infringements occurred, the team would be awarded a penalty with an option to tap the ball or kick for touch to gain field possession advantage. Prior to the new rules change, teams tactically manipulated these penalties as periods to increase rest and ‘slow’ the speed of play. As part of the COVID-19 restrictions, reducing scrums aimed to moderate the transmission of the COVID-19 virus via physical contact [5]. The rule changes aimed to improve key in-game statistics, including increased playing intensity and a greater spectacle for fans with an increase in tries scored, line breaks, and tackle breaks.

While the activity profiles of NRL players have been studied following the implementation of the above-mentioned rule changes, no study has investigated individual player wellbeing or team performance related to the introduction of the six-again rule change [5,18]. Performance statistics along with player wellness data can provide insight into the demands of elite rugby league match- play, the athlete-reported fatigue associated with match-play, and consequently, facilitates better decision making and design of position-specific training and recovery programs [19,20]. Therefore, updated information derived from team and individual performance metrics due to rule changes is crucial to high performance coaches who require detailed understanding of the demands placed on the athletes during match-play to plan, design and implement training programs [17]. The impact of the six-again rule change has received limited research investigation with only a single study examining these changes. The authors reported greater acceleration intensity following the rule change [18].

While Delves et al., provided an important starting point for the study on rule variations, to date no studies have investigated the key match performance statistics and individual athlete-reported wellness responses before and after the introduction of the rule changes [18]. With this in mind, the aim of this study was to investigate the effect of the six-again and ‘immediate change of possession’ rule changes on individual activity profiles and team performance statistics in the elite NRL competition. Our second aim was to investigate the impact of these rule changes on individual player wellbeing scores.

Methodology

Experimental design

As the six-again rule was introduced between rounds 2 and 3 of the 2020 NRL season. This resulted in 217 total games played by all teams within the competition before the introduction of the six- again rule and 354 games after its introduction. All game statistics were collected by stats perform and publicly available on NRL.com and included ‘tries’, ‘all run meters’, ‘post-contact meters’, ‘tackles’, ‘tackle breaks’, ‘play the balls’, and ‘errors’.

Subjects 60 male rugby league players (mean+SD; age 25.41 yr+3.16 yr; height 185.5 cm+4.69 cm; body mass 98.2 kg+8.49 kg), competing in the NRL participated in the study. The present study was undertaken across three consecutive NRL competitive seasons with data collected during 20 NRL competition matches in season 2019, 24 NRL competition matches in 2020, 2021 and 2022. Prior to the study, all athletes attended a presentation by the chief investigator that detailed the research purpose and methods. The study was approved by the Human Research Ethics Committee (HREC).

Athlete-reported wellness

Participants were instructed to complete a pre-designed questionnaire using an online application (Smartabase, QLD, and Australia) in the morning and ~36 hours before each competition game. The questionnaire was based on previous literature and required participants to enter their current perceptions of sleep quality, fatigue, muscle soreness, stress and mood by using a five- point Likert scale. From each player, a total wellness score was then calculated by summing the scores of all five questions. All participants completed the questionnaires on the same day, in an allocated 60- min period from their own mobile device, on their own without any peer or staff pressure. Subjects were well rehearsed in completing the questionnaires before the start of the competition season. There were 757 wellness scores reported across the team’s 74 games (59 observations prior to the introduction of the rule changes and 698 observations after the introduction of the rule changes).

Statistical analysis

Athlete-reported wellness: For the self-reported wellness data, a mixed model was used with the standardized total wellness score as the dependent variable, the dichotomous ix-again variable as the fixed effect, with the Player as a random intercept.

Match-play performance statistics

Mixed models were used to analyse the game statistics data. A Gaussian distribution was used for all statistics except for tries, in which a Poisson distribution was used. In all models, the game statistic was the dependent variable, a dichotomous six-again variable (Pre-introduction or Post-introduction) was set as the fixed effect, with both the Team and opposition set as random intercepts. Effect sizes and associated confidence intervals were calculated using the effect size package. This statistical package was used to analyze all data.

Results and Discussion

Athlete-reported wellness

There was a significant positive association (p<0.05) between self-reported wellness and the introduction of the six-again rule. Given a standard deviation of 2.62 wellness scores, a change of 0.33 z-scores in wellness would indicate an average rise of 0.86 wellness score points after the introduction of the six-again rule. These results are seen in Table 1.

Table 1: Self-reported wellness before and after the introduction of the six-again rule change.

Match performance

Across the 571 games, there was on average, 6.2 (95% CI: 4.4 to 8.1) additional play-the-balls per team after the introduction of the six again rule. This led to a significant increase in run meters, post-contact meters, and tackles per team. On average, there was a significant increase in tries, while there was a significant decrease in tackle breaks per team. There was no significant difference (p=0.126) in the number of errors before and after the introduction of the six- again rule. Outside backs experienced a significant increase in the number of tries scored per game (1.77) compared to the adjustable and forwards positional groups. All of the game statistics comparisons can be seen in Table 2.

Table 2: Game performance statistics before and after the introduction of the six-again rule.

Impact of rule changes

This study is the first to describe the effect of the ‘six-again’ rule change implemented in the 2020 NRL competition, on team performance metrics. In addition, this is the first study to report player self-reported wellness response to the new rule changes. The main findings demonstrate a significant increase in team derived game performance metrics after compared to before the introduction of the six-again rule. Moreover, amid the 571 games, there was a significant increase in run meters, post-contact meters, and tackles per team. On average, there was a significant increase in tries, although despite the introduction of the six-again rule change there was a significant decrease in tackle breaks per team. In addition to game metrics, there was a significant positive association between self-reported wellness and the introduction of the six-again rule. Given the ability to analyse match data before and after the introduction of the new rules, and the lack of studies investigating the impact of the implementation of the six-again rule change in the NRL; the current study aimed to fill this gap in the literature.

Following the mandatory lock down of all competition sport in Australia during the COVID-19 pandemic, the NRL implemented new rule amendments to positively impact the ‘speed of the game’ via increase in key match performance game metrics. Further defining ‘speed of game’ terminology; this can be described by greater attacking opportunities (e.g., running, line breaks, tackle breaks and tries scored) leading to an increase in unbroken play. The NRL competition committee has positively achieved this as measured by a significant increase of 79.1 (54.1 to 104.1) run meters and 100.9 (89.2 to 112.6) post-contact meters as depicted in Table 3. Run meters has been reported to be a key indicator of ‘winning’ teams in the NRL; with greater winning teams possessing greater run meters indicating superior attacking strategies [11]. The increase in run and post-contact meters following the implementation of the six-again rule likely reflects a more continuous, flowing game which increased ‘speed of play’.

Table 3: Differences in standardised total wellness (z-score) before and after the introduction of the six-again rule.

This study was built on the work completed by Delves et al., who investigated the effects of the introduction of the six again rule and acceleration intensity [18]. The main findings from Delves et al., work revealed peak acceleration intensity of NRL athletes substantially increased across all positions groups in the 2020 and 2021 seasons compared to the 2019 season [18]. Ball-in-play phase lengths were greater in season 2020 compared to 2019 (ES=0.57; +0.51) following the modification of the competition rule changes [18]. Whilst direct comparison with the preceding research is challenging due to numerous methodology differences; the work by Delves et al., and others [18,21]; gives credibility to longer ball in play time believed to be a major contributor to the increase in ‘speed of game’ results as reported in the current study. Increase in unbroken play (longer ball in play time) in the current study is likely achieved after the removal of static error and penalty rules (i.e., scrums and kicking for touch penalties). Prominently there was a significant increase in extra play the balls (6.2 (95% CI: 4.4 to 8.1)) and tackles per team (8.3 (3.8 to 12.8)) following the rule change. This expected results likely contributed by unbroken ball in play time as a positive outcome of the removal of stagnant scrums and penalties replaced by six-again speed of play. Critically, given the current study results, training should be structured to meet the updated specific match play tactical demands (i.e. tacking drills and play the ball speed). As mentioned above, the objective behind implementing the rule change was to positively increase the ‘speed of the game’; from a practical standpoint, these findings, combined with those of Delves et al., reflect a need for specific, higher-intensity physical training to adequately prepare players for the evolving demands of the game [18]. The ability to increase cardiovascular response and skill under fatigue is crucial to individual success with Gabbett et al., the first to report high level of physical fitness is required to repeatedly perform selected skill characteristics not just physiological and anthropometric measurements that contribute to effective playing ability in comparison to junior through to senior level rugby league players [22]. Although the previous authors raised conflicting comparisons with previous work that displayed physiological and anthropometric characteristics did play a significant role in comparisons to different age and playing level in rugby league players. Additionally, this also raises the question if the rule changes have widened the gap on winning vs losing teams, although work completed by Hulin et al., reported physical demands of match play on successful vs less successful teams demonstrated technical and tactical differences, rather than activity profiles be responsible for greater success in NRL competition match play [23-25].

Despite reporting on average, a significant increase of 0.64 (95% CI: 0.41 to 0.86) tries in the current study, a significant decrease of 1.5 (0.5 to 2.5) tackle breaks per team was shown. Gabbett et al., identified over 50% of Repeated High Intensity interval bouts (RHIE) occurred within 5 min of a try scored or conceded [25]; concluding successful teams perform RHIE to prevent tries; while unsuccessful teams work harder to score tries. This again raises the question if the introduction of the six-again rule changes has favored more successful teams. There was no significant difference (p=0.126) between the number of errors before and after the introduction of the six-again rule. This is a crucial outcome to judge the success of the introduction of the six-again rule change from the NRL competition committee and fans, given if errors also increased this would likely correlate with fewer ball in play time and reduction in speed of the game results would most likely follow.

A unique finding of this study was the significant positive association (p<0.05) between self-reported wellness and the introduction of the six-again rule. Given a standard deviation of 2.62 wellness scores, a change of 0.33 z-scores in wellness score would indicate a rise, on average, of 0.86 wellness score points after the introduction of the six-again rule. The probable explanation is due to the replacement of scrums and penalties to the six-again rule leading to a positive increase in tries scored and total match points; therefore likely reducing the impact physically on the athletes. Practically, the new rule changes made a positive impact of player’s well-being and provided greater positive feelings towards the game and subsequent rule changes. Given this, it would be beneficial for future work to investigate player movement patterns measured using data collected via the Global Navigation Satellite System (GNSS) before and after the rule change [26].

Practical implications

The aim of this study was to investigate the implementation of the six-again rule change during the 2020 NRL season and compare to previous and post sessions 2019 and 2021 respectively, on team performance statistics captured during competition match play. Further specific aims were to investigate the impact of rule changes on individual self-reported player wellbeing scores. The current study has clearly demonstrated the implementations of the six-again rule changes from the NRL competition resulted in:

• An increase in play the balls, run meters, post-contact meters, and tackles per team.

• An increase in tries scored.

• A significant decrease of tackle breaks per team.

• No significant difference between the numbers of errors.

A significant positive association between self-reported wellness and the introduction of the six-again rule.

Conclusion

In conclusion, as a result of the COVID-19 global pandemic, the NRL competition committee was tasked to implement one rule change with the object to ‘increase’ speed of the game. This study along with the work completed and supports that notion this was achieved through increase in all run meters, post-contact meters, tackle breaks and tries scored. From a statistical standpoint, the implications are profound. Shifts in game duration, frequency of play interruptions, and scoring patterns have influenced player fatigue, injury rates, and recovery needs. The data underscores the importance of tailored conditioning regimens that address the specific demands posed by these rule adjustments.

Limitations

Despite the practical implications of this study, it is not without limitations. Previous research investigating the impact of rule changes showed positive effect associated with the implementation of the 10 m rule change and significant increases in accelerations; respectively. The match characteristics reported in the current study although showed positive impacts of speed of play determinants; this may not be due to the new rules implemented, and could fundamentally be due to an increase in player physical fitness status, as a benefit of prolonged rest during the mandatory suspension of the NRL competition and furthermore; specific and targeted training program to prepare for the restart on the competition after a forced lockdown. Further limitations exist with the lack of Global Positioning System (GPS) analysis applied and the ability to directly compare to equivalent research work on rule changes and additional research conducted around monitoring analysis of physical demands of NRL competition match play. The inclusion of League wide match statistics gives the paper sample power credibility and non-biased data; however the collection of self-reported wellness response from a single team reduces the ability to create greater statistically power analysis. Due to these limitations discussed; further research with technology data sets is warranted; and continuous research investigating seasonally to provide regular feedback on rule changes to potential identify impact on game characteristics to provide high performance practitioners with specific match performance data to help plan and prepare tailored training and recovery programs in the future.

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