Effect of defensive pressure on international women's rugby sevens attacking skills frequency and execution

Abstract

The aim of the present study was to determine the effect of defensive pressure on the execution of attacking skills in international women's rugby sevens. Performance analyses were conducted across 42 training camp drills during the 2012–2013 season. Training camp sessions were recorded using a video camera positioned from an aerial perspective, with the attacking team's performance analysed during game-based drills. Technical skills assessed included pass type, pass accuracy, catching, evasive moves and line breaks. Results indicated that defensive pressure had a significant effect on a player's pass type, evasive moves and line breaks (p < 0.05), but no significant effect on passing accuracy and catching skill (p > 0.05). A cut-out pass (standard residual = 3.3) was more likely to happen than expected by chance during no defence. An offload was more likely to occur than expected by chance during contested defence (standard residual = 9.6). A line break (standard residual = 4.7) and a swerve (standard residual = 2.5) were more likely to happen than expected by chance during contested defence. Coaches should progressively overload the degree of defensive pressure during training. This may encourage the performance of non-conventional passes under contested defensive pressure, more closely reflecting the requisites of competition game-play.

Keywords

Game-based practice notational analysis rugby football technical skills

Introduction

The popularity of rugby sevens has seen a recent increase since the inclusion of both men's and women's tournaments at the 2016 Olympic Games in Rio de Janeiro, Brazil. Although reflecting similarities to rugby union with regards to rules and field size, rugby sevens is unique, with teams consisting of only seven on-field players, three forwards and four backs. Additionally, matches are played across two 7-min halves with a 2-min half-time interval.^1,2 Comparatively, rugby union has up to 15 players fielded at any given time, with matches played across two 40-min halves. Consequently, the increased space available for rugby sevens players during game-play is likely to manifest into different technical and perceptual demands when compared to rugby union. Most notably, it could be expected that rugby sevens players will accrue a greater count of ball possessions and technical skill involvements per minute of game-time, while simultaneously requiring a greater perceptual effort (i.e. decision-making) per minute of game-time.³

Technical analysis of rugby sevens match demands is limited with virtually all of the research focusing on men's rugby sevens match data. As a result of the limited data and the scarcity of literature relating to women's rugby sevens, information and conclusions made about the game of rugby sevens are typically based on men's rugby sevens data. It is acknowledged that men's and women's rugby sevens could employee different technical and tactics skills, therefore presenting alternative performance measures that differentiate successful and unsuccessful teams. For example, Barkell et al.⁴ have reported that there are common performance variables based on the game of rugby sevens; however, there are also additional gender specific variables that differentiate successful and unsuccessful teams.

Recent performance analyses conducted in international men's rugby sevens illustrated the importance of technical skill, with greater ball retention and efficiency in attack discriminating successful teams from their less-successful counterparts.³ Further, Hughes and Jones⁵ demonstrated that successful teams maintained greater time in possession of the ball compared to less successful teams. However, an increased possession time per try and passes per try have both been associated with a lower team ranking during international competitions.⁶ Consequently, it is crucial for teams to be efficient in attack in order to optimise their chances of success. This efficiency may be enhanced through a reduction in conventional (normal player to player) passes and an increase in more non-conventional (which include cut-out, dummy, switch and an offload) passes.⁵ As such, non-conventional passes may be considered more complex given their imposition of a higher level of defensive decision-making placed upon the opposition. Subsequently, it could be expected that attacking teams with a higher level of technical and perceptual skill when performing non-conventional passes will be advantageously positioned for success during tournaments. By quantifying a number of technical skills contributing to attacking efficiency, this may therefore enable the development of improved training practices and assist with improving players' attacking technical and perceptual skill.

In order to transition from a semi-professional, decentralised program to an internationally recognised professional sport, a large number of teams within the World Rugby Women's Sevens Series have programs that are now centralised.⁷ Despite being centralised, training camps still play an important role in the preparation for international tournaments. For instance, training camps are often used to introduce additional players for tournaments, which is of use for injury and/or team selection strategies. Further, such camps provide an environment in which players can train and develop technical and perceptual skills required in forthcoming tournaments. As such, coaches should recognise the environmental and task constraints that influence a player's technical and/or perceptual skill execution during game-play in order to tailor purposeful training sessions.⁸

One of the more influential environmental constraints imposed upon a team's performance is the level of opposition defensive pressure.⁹ Increased defensive pressure has been demonstrated to result in acute decreases in ball accuracy of attacking players during a soccer cross¹⁰ and field goal shooting percentage in basketball.⁹ Thus, game-based training drills should reflect similar defensive pressures imposed by opposition players during competition game-play. Facilitating this may therefore enable players with the capability to optimally perform under periods of opposition defensive pressure. Moreover, a gradual progression of defensive pressure incorporated into a training context may allow the players to become better attuned to the key perceptual information, thereby increasing the probability of identifying the correct decision, and programming the correct response execution during game-play.^8,11 In order to develop the technical and perceptual skills performed under the defensive pressure of competition, the interaction between the physical, technical and tactical demands also needs to be assessed during training.

To date, there are no published data that describes the interaction between technical and perceptual skill and defensive pressure in women's rugby sevens. This study, therefore, aimed to determine the effect of defensive pressure on the frequency and execution of attacking skills in international women's rugby sevens during training camps.

Methods

Subjects

The study included 24 female rugby sevens players (age 24 ± 5 years, height 168 ± 5 cm, body mass 68 ± 6 kg; mean ± SD) that were all a part of the same international team. Analyses were conducted across 42 preparation training camp drills during the 2012–2013 international women's rugby sevens season. The training drills were recorded over seven preparation training camps with all players providing written informed consent, with the team manager providing written consent for players less than 18 years of age to participate in the present study. The present study was approved by the Institutional Ethics Committee.

Training analysis

Training drills were recorded with a Sony digital high definition video recorder (HDR – XR260E, Sony, California, USA) with a remote control tripod (VCT – 80AV, Sony, California, USA). The varying locations of training camps meant that video footage was captured with elevation ranging from 5 to 15 m above the training ground, with the camera placed at the halfway line of the field. The attacking team's performance was analysed during game-based drills and only periods of activity were included in the duration of each drill. The game-based drills were chosen for analysis due to the similarities to match demands, as determined by the coaching staff. The aim of the game-based drills was to focus on the technical and perceptual skills of a match, so all game-based drills were conducted using the full field with seven attacking players and seven defensive players, except during no defence. Game-based drills were evenly distributed across training camps and between morning and afternoon training sessions. The description, number of occurrences, total duration and average duration of each game-based drill during training camps are presented in Table 1. Manual notational analysis was performed with no specific coding software used. Windows Media Player (Microsoft, Washington, USA) was used to view video footage, which was analysed in lapsed time, where the analyst was permitted to pause and replay video footage, to enhance the accuracy of their notation.¹² Notational sessions were conducted over a maximum of 2 h, with at least a 1-h recovery between analysis sessions.¹²

Table 1.

Description and distribution of time spent in each game-based drill for all training camps.

Game-based drills	Description	Total occurrences	Total duration (min)	Average duration (min)
Fiji	Once touched or tackled return to halfway and start attacking movement again. The drill focused on passing, evasive moves and efficiency in attack.	6	45	8 ± 4
Penalties	Taking penalties from varying locations on the field. The drill aim was to work on tactics and attacking movements from different locations.	4	12	3 ± 1
Restarts	Receiving restarts. The drill focus was to work on formation and set-up for receiving restarts and the tactics and ball movement from a restart.	8	37	5 ± 2
Rucks	Rucks at varying field locations, with the coaching staff varying the speed of ball release from the ruck. The drill aimed to develop team tactics depending on the location and the speed of ball release from the ruck.	6	45	8 ± 3
Set-piece	Includes the set-up and execution of attacking scrums and line-outs. Coaching staff were developing technical elements associated with performing a scrum or line-out combined with the ball movements and tactics the team were aiming to execute.	8	52	6 ± 2
Team play	Is an integration of all skills developed. The drill focus was to combine all skills and tactics learnt and apply it to a variety of situations as opposed to just being used in isolation. Coaches also utilised the drill to evaluate if players have an understanding of team tactics.	10	87	9 ± 4

Attacking outcome measures

The attacking outcome measures for the present study were based on the rugby sevens match literature, and the tactical importance of maintaining ball possession and efficiency in attack.^5,12 The attacking outcome measures included pass type, pass accuracy, catching, evasive moves and line breaks that were all analysed per player possession in relation to the three varying levels of defensive pressure. The distribution of time spent and the number of passes performed in each type of defensive pressure are shown in Table 2.

Table 2.

Distribution of time spent and the number of passes performed in each type of defensive pressure.

Defensive pressure	Total occurrences during drills	Total duration (min)	Average duration (min)	Total passes performed	Average passes per min
No defence	8	44 (16%)	5 ± 3	764	17 ± 2
Uncontested defence	29	188 (67%)	6 ± 4	2337	13 ± 3
Contested defence	8	46 (17%)	6 ± 2	576	12 ± 4

Defensive pressure

Defensive pressure is an important environmental constraint given its influence on an attacking team's performance and success.^9,13,14 Defensive pressure was described as,

No defence. No opposing players in a defensive line.

Uncontested defence. Opposing players present in a defensive line, but were only allowed two handed touches on the attacking team, with no contact or contest during the ruck. A two-handed touch was considered as a tackle with the attacking player going to the ground for the play to be restarted by a ruck clearance.

Contested defence. Opposing players in a defensive line who were allowed to make full contact including tackling and rucking.

Pass type

Successful rugby sevens teams may need to utilise a variety of passes to be efficient in attack and make line breaks.⁵ Consistent with previous studies,^5,12 pass type was classified as,

Conventional. The ball is thrown backwards and laterally to another attacking player.

Cut-out. The ball goes past one or more attacking players to another attacking player.

Dummy. The ball is ‘faked’ to a teammate, but does not leave the player in possession.

Switch. The ball goes in the opposite direction to the movement of the passing player.

Offload. The ball is passed after the ball carrier makes contact with at least one defensive player.

Based on the above definitions, the term ‘non-conventional’ was used to describe the following passes (a cut-out, dummy, switch and an offload pass).

Pass accuracy

Pass accuracy is an essential technical skill for rugby sevens, as it allows attacking teams to move the ball to a player in a better attacking position and attack with greater efficiency under defensive pressure.^3,15 Consistent with previous research,¹² passing accuracy was defined as,

Good. The ball was received between chest and hip height. At most, minor adjustments to posture or line of motion were made by the catcher to receive the pass.

Moderate. The ball was received between chest and head height or between hip and knee height. Adjustments to posture or line of motion were made by the catcher to receive the pass.

Poor. The ball was received by reaching above head height, below knee height or the ball did not get to the player on the full. Major adjustments to posture or line of motion were made by the catcher to receive the pass.

Catching

Successful teams are able to limit errors and maintain possession of the ball better than unsuccessful teams, limiting the time their opposition are in possession and their opportunities to score.^3,16 Catching was categorised as,

Successful. The receiving player catches the ball.

Unsuccessful. The receiving player drops the ball either forward or backwards, regardless of pass quality.

Evasive move

Successful teams are more efficient in attacking and executing an evasive style of play, not only through passes but with evasive moves.^5,6 An evasive move was defined as non-linear motion where a player tries to get around or avoid an opponent.¹⁷ Consistent with previous studies,¹⁷ evasive moves includes,

Side-step. Involves a sideways stepping motion to avoid an opponent.

Swerve. A forward change of direction in order to get around an opponent.

Line break

During international rugby sevens matches, successful teams had more line breaks compared to unsuccessful teams.⁵ A line break was defined as when an attacking player gets through the opponent's defensive line while in possession of the ball.¹⁸ A line break could only occur during the contested and uncontested defensive pressure environments. Consistent with previous studies,^5,18 line breaks were classified as,

Yes. A line break occurred.

No. A line break did not occur.

Reliability

Intra-tester reliability of all outcome measures was established by analysing six training camps drills from a variety of elevations 7 days apart. The reliability procedures were based on established protocols that are advocated for the use in performance analysis literature.^12,17 Specifically, the Kappa statistic (κ) was used to assess the level of agreement between the two scoring occasions given the categorical nature of the data. The level of agreement was defined as follows: <0 less than chance agreement, 0.01–0.20 slight agreement, 0.21–0.40 fair agreement, 0.41–0.60 moderate agreement, 0.61–0.80 substantial agreement and 0.81–0.99 almost perfect agreement.¹⁹

Statistical analysis

Data were presented as a percentage within each of the defensive pressure categories to account for the variation of time spent training in the three levels of defensive pressure. Chi-squared (χ²) tests were used to examine the association between the different levels of defensive pressure and the attacking skills of rugby sevens players. Data were presented as degrees of freedom, chi-squared statistic and level of significance. Chi-squared tests were determined by comparing an observed frequency for a particular category to an expected frequency for that category. The standard residual (SR) provides further insight into the subcategories that contributed to the chi square and to understand the association between defensive pressure and the probability of the different skills being observed. SRs are an indication of how many deviations above or below frequencies observed in particular subcategories are to the frequencies you would expect to observe in those subcategories by chance.²⁰ A value ≥ 2.0 is typically used to represent an event that was more likely to happen than expected by chance, whereas a value ≤ −2.0 represented an event that was less likely to occur than expected by chance. Thus, a SR threshold of ≥ 2.0 and ≤ −2.0 provides practically meaningful results regarding the changes in observed variables between defensive pressure conditions.²⁰ The level of significance was set at α < 0.05, with SPSS (version 20, SPSS Inc. Chicago, USA) used for all statistical analyses.

Results

The strength of the intra-tester reliability revealed a near perfect level of agreement (range = 0.91–1.00). The mean Kappa statistic of ĸ = 0.98 was similar to previous work conducted in rugby league and rugby union and was thus considered acceptable.

Chi-squared analysis revealed a significant association between defensive pressure and the frequency of pass type (χ²(8) = 190.6, p < 0.001). A cut-out pass (SR = 3.3) and dummy pass (SR = 2.3) were more likely to happen than expected by chance during uncontested defence, however a cut-out pass (SR = −3.6) and dummy pass (SR = −3.7) were less likely to happen than expected by chance during no defence. A cut-out pass (SR = −2.6) was also less likely to occur than expected by chance during contested defence. A switch pass was more likely to happen than expected by chance during no defence (SR = 3.7) and less likely to happen than expected by chance during contested defence (SR = −3.2). An offload was less likely to happen than expected by chance during uncontested defence (SR = −2.2) and more likely to occur than expected by chance during contested defence (SR = 9.6) (Figure 1).

Figure 1.

The association between defensive pressure and the frequency of conventional, cut-out, dummy, switch and offload passes. *Significant association (SR ≥ 2.0 or SR ≤ −2.0). SR: standard residual.

Defensive pressure had no significant effect on the frequency of accurate passes (χ²(4) = 13.2, p = 0.067). No defence had the most accurate passing with 60% good accuracy compared to 55% during contested defence. No SR achieved significance, with the closest being a good pass, that was more likely to occur than expected by chance during no defence (SR = 1.9) (Figure 2).

Figure 2.

The association between defensive pressure and the frequency of good, moderate and poor passes. SR: standard residual.

The percentage of successful catches was greater than 95% for all levels of defensive pressure (Figure 3). There was no significant association between defensive pressure and the frequency of successful and unsuccessful catches (χ²(2) = 2.6, p = 0.279). All SR were non-significant, ranging from −1.4 to 0.5. Defensive pressure had a significant effect on the frequency of evasive moves performed (χ²(2) = 11.2, p = 0.004) and the frequency of line breaks (χ²(2) = 69.9, p < 0.001). A swerve (SR = 2.5) was more likely to occur than expected by chance during contested defence. During contested defence, 9% of all ball carries resulted in a line break, which was more likely to happen than expected by chance (SR = 4.7).

Figure 3.

The association between defensive pressure and the frequency of successful and unsuccessful catches, evasive moves and line breaks. *Significant association (SR ≥ 2.0 or SR ≤ −2.0). SR: standard residual.

Discussion

The present study provides insight into the technical skills of rugby sevens training camps sessions in relation to varying levels of defensive pressure. By gaining insight into how varying the environmental constraint of defensive pressure affected skill frequency, coaches may be able to improve the periodisation and progression of technical and perceptual training drills. In turn, this may assist with the acquisition of technical and perceptual skills in pressured contexts during game-play.

Passing is an essential technical skill in rugby sevens, with the present study demonstrating that there was a significant association between defensive pressure and the frequency of pass type. A conventional pass was the most common type performed during all three levels of defensive pressure. Non-conventional passes including a switch and a cut-out were more likely to occur than expected by chance during no defence and uncontested defence, respectively. In comparison to these results, a cut-out and a switch pass were less likely to occur than expected by chance during contested defence. The reduction in the frequency of non-conventional passes during contested defence was not expected, as it was hypothesised that the players would perform more of the non-conventional passes to attack with greater attacking efficiency (as defined by a smaller number of passes per try) to overcome the increased defensive pressure. The present study's hypothesis was based on research demonstrating higher ranked teams in international men's rugby sevens tournaments had greater attacking efficiency⁵ and an increased capability to maintain possession of the ball, with more passes per try being associated with a lower team ranking.³ Such findings are somewhat paradoxical in that the best teams may need to utilise non-conventional passes to make line breaks against very good defences. It is however, also conceivable that teams could attack with greater efficiency through improving their performance of conventional passes and their positioning on the field. A number of reasons may explain the reduction of non-conventional passes with contested defensive pressure. Namely, the greater physical demands of impacts, rucks and tackles performed during contested defensive pressure, may have contributed to increased physical and cognitive fatigue. It is also possible that the increased defensive pressure reduced the time the attacking players had to make decisions regarding, when and how to perform technical skills such as running, passing and catching. Coaches, therefore, need to be aware of the interaction between physical, technical and perceptual demands during game-play.

The present study has demonstrated that during game-based drills, where there was contested defensive pressure, the attacking team performed fewer non-conventional passes. In order to promote the execution of non-conventional passes coaches may need to alter the task constraints, namely the instructions, cues and/or feedback provided during contested defence, game-based drills. The frequent practice of non-conventional passes during contested defence will better prepare the players to execute these passes in contested defensive situations inherent to competition.²¹

While the type of pass is essential to the tactics employed, the importance of accurate passing during rugby sevens matches should not be underestimated. The present study found that there was no meaningful association between defensive pressure and pass accuracy, with good passes only exhibiting a 5% decrease and poor passes a 3% increase from no defence compared to contested defence, respectively. The present study reported a substantially smaller decline in passing accuracy than that observed by Orth et al.,¹⁰ who found passing accuracy decreased from 78% for a defender absent to 59% for a defender near during soccer drills. While the decline in passing performance was better during the present study, rugby sevens players may have been able to maintain passing accuracy by performing fewer non-conventional passes. Players may have also chosen to perform non-conventional passes as a safer option due to the situation of preparation training camps, where team selection was finalised. By encouraging the performance of non-conventional passes during contested defensive pressure, players will be increasingly exposed to the relevant perceptual information, which should assist in the development of the appropriate perceptual-action coupling and transfer of skills from training to match performance.^21,22

The present study found that there was no significant effect of defensive pressure on the catching ability of rugby sevens players. Women's rugby sevens players caught the ball greater than 95% of the time, regardless of the level of defensive pressure or pass accuracy. The consistency of women's rugby sevens players catching ability reflects similarities to findings of Hughes and Jones,⁵ who also did not report differences in handling errors between successful and less successful teams during men's rugby sevens matches. While a poor pass was still likely to be caught by the players in the present study, it may have required the catching player to change direction, speed and/or devote a greater degree of attention to the task of catching the pass, reducing efficiency in attack.^23,24 Maintaining possession is linked to both the passing and catching skill of rugby sevens players and has been shown to be a key determinant for successful teams in rugby sevens tournaments.²⁵ The present study's results and that of the literature^3,6 suggest that while catching is important, rugby sevens players and coaches may need to focus more of training on improving the frequency of non-conventional passes during contested defensive pressure.

Our results demonstrated that defensive pressure influenced the frequency of line breaks and evasive moves, with line breaks and swerves more likely to happen during contested than uncontested defence. Further, contested defence had the highest number of line breaks with 9% of all ball carries resulting in a line break. A higher number of evasive moves such as a side-step or swerve were associated with successful teams compared to less successful teams during men's rugby sevens matches.⁵ With the potential for players to be more closely aligned and compressed during contested defence, more space is created away from the ruck at the end of the defensive line, encouraging players to perform a swerve in order to create line breaks. During contested defence, players may be more compressed because of the increased demands to tackle as opposed to uncontested defence, which only involved two handed touch. Two handed touch required for uncontested defence may allow the defence to cover a greater area by not requiring additional players to commit to the breakdown or support the tackler in case of a missed tackle. With only seven players on the field, committing two players to a tackle or ruck situation during contested defence creates space in the defensive line that the attacking team need to be able to utilise effectively. Contested defence, therefore provides opportunities for rugby sevens players to develop the essential skills required for evasive moves and line break situations.

Conclusion

In conclusion, defensive pressure meaningfully alters the frequency of technical skill executions. Specifically, the more frequent execution of conventional passes during contested defence suggests that the coaches should consider altering the task constraints, instructions, cues and/or feedback given during contested defence, game-based drills. Such alterations should also encourage the performance of non-conventional passes, so that the players are better able to execute these passes in contested defensive situations inherent to competition.²¹ By encouraging the performance of non-conventional passes and continuing to improve passing accuracy during contested defensive pressure, players will be increasingly exposed to the relevant perceptual information that should assist in the development of the appropriate perceptual-action coupling and transfer of skills from training to match performance.^21,22 Contested defence was also shown to provide opportunities for rugby sevens players to develop the essential skills required for evasive moves and line break situations. Coaches should consider the findings presented in this study in order to optimise the transference of training to competition with regards to technical and perceptual skill execution.

Footnotes

Acknowledgements

The authors would like to gratefully acknowledge the participation and cooperation of players and coaching staff from the Australian Women's Rugby Sevens team. The authors would also like to thank the Senior Research Assistant and Statistician Evelyne Rathbone, for her assistance with statistical analysis during the present study.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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