scholarly journals Development of an expected possession value model to analyse team attacking performances in rugby league

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259536
Author(s):  
Thomas Sawczuk ◽  
Anna Palczewska ◽  
Ben Jones
Keyword(s):  
Markov Chains ◽  
Rugby League ◽  
Kl Divergence ◽  
Location Data ◽  
Leibler Divergence ◽  
Value Model ◽  
Super League

This study aimed to evaluate team attacking performances in rugby league via expected possession value (EPV) models. Location data from 59,233 plays in 180 Super League matches across the 2019 Super League season were used. Six EPV models were generated using arbitrary zone sizes (EPV-308 and EPV-77) or aggregated according to the total zone value generated during a match (EPV-37, EPV-19, EPV-13 and EPV-9). Attacking sets were considered as Markov Chains, allowing the value of each zone visited to be estimated based on the outcome of the possession. The Kullback-Leibler Divergence was used to evaluate the reproducibility of the value generated from each zone (the reward distribution) by teams between matches. Decreasing the number of zones improved the reproducibility of reward distributions between matches but reduced the variation in zone values. After six previous matches, the subsequent match’s zones had been visited on 95% or more occasions for EPV-19 (95±4%), EPV-13 (100±0%) and EPV-9 (100±0%). The KL Divergence values were infinity (EPV-308), 0.52±0.05 (EPV-77), 0.37±0.03 (EPV-37), 0.20±0.02 (EPV-19), 0.13±0.02 (EPV-13) and 0.10±0.02 (EPV-9). This study supports the use of EPV-19 and EPV-13, but not EPV-9 (too little variation in zone values), to evaluate team attacking performance in rugby league.

scholarly journals Injury in rugby league football: the new super league.

1997 ◽  
Vol 31 (1) ◽  
pp. 85-85 ◽  
Author(s):  
C Gissane ◽  
L H Phillips ◽  
D Jennings ◽  
J White ◽  
A Cumine
Keyword(s):  
Rugby League ◽  
Super League

scholarly journals Reduction of Markov Chains Using a Value-of-Information-Based Approach

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 349 ◽  
Author(s):  
Isaac Sledge ◽  
José Príncipe
Keyword(s):  
Markov Chains ◽  
Value Of Information ◽  
Free Parameter ◽  
A Priori ◽  
Information Criterion ◽  
Joint Space ◽  
Information Theoretic ◽  
A Value ◽  
Order Markov Chain ◽  
Leibler Divergence

In this paper, we propose an approach to obtain reduced-order models of Markov chains. Our approach is composed of two information-theoretic processes. The first is a means of comparing pairs of stationary chains on different state spaces, which is done via the negative, modified Kullback–Leibler divergence defined on a model joint space. Model reduction is achieved by solving a value-of-information criterion with respect to this divergence. Optimizing the criterion leads to a probabilistic partitioning of the states in the high-order Markov chain. A single free parameter that emerges through the optimization process dictates both the partition uncertainty and the number of state groups. We provide a data-driven means of choosing the `optimal’ value of this free parameter, which sidesteps needing to a priori know the number of state groups in an arbitrary chain.

scholarly journals Hydration strategies of professional elite rugby league referees during super league matches

2016 ◽  
Vol 11 (1) ◽  
pp. 116-121 ◽  
Author(s):  
Ben Jones ◽  
Kevin Till ◽  
Stacey Emmonds ◽  
Roderick FGJ King ◽  
Michael P Gray ◽  
...  
Keyword(s):  
Rugby League ◽  
Super League

scholarly journals The Duration-specific Peak Average Running Speeds of European Super League Academy Rugby League Match Play

2019 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Sarah Whitehead ◽  
Kevin Till ◽  
Dan Weaving ◽  
Nick Dalton-Barron ◽  
Matt Ireton ◽  
...  
Keyword(s):  
Rugby League ◽  
Match Play ◽  
Super League

scholarly journals Top secret training data? External training loads of a cup winning English Super League rugby league team

2017 ◽  
Vol 13 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Christopher J Black ◽  
Kevin Till ◽  
John P O’Hara ◽  
Jason Davidson ◽  
Ben Jones
Keyword(s):  
Rugby League ◽  
Training Data ◽  
External Training ◽  
Super League

scholarly journals A Comparative Analysis of Competitive Balance Between a Closed and an Open League in Rugby League

2021 ◽  
pp. 152700252110222
Author(s):  
Daniel Read ◽  
Aaron C.T. Smith ◽  
James Skinner
Keyword(s):  
Labor Market ◽  
Comparative Analysis ◽  
Rugby League ◽  
Competitive Balance ◽  
Equal Chance ◽  
Labor Market Regulations ◽  
Super League

League regulators aim for an equitable competition where each team has an equal chance of winning the championship, termed competitive balance. It is generally assumed that closed leagues with stricter labor market regulations should demonstrate better competitive balance than open leagues with promotion and relegation. The aim of this research was to examine the competitive balance between and within seasons in the closed Australian National Rugby League (NRL) and open English Super League using five measures of concentration and dominance. Overall, the closed NRL competition demonstrated superior competitive balance. The practical and theoretical implications of the findings are discussed.

scholarly journals The anthropometric and physical qualities of women’s rugby league Super League and international players; identifying differences in playing position and standard

2021 ◽  
Author(s):  
Sean Scantlebury ◽  
Sam McCormack ◽  
Thomas Sawczuk ◽  
Stacey Emmonds ◽  
Neil Collins ◽  
...  
Keyword(s):  
Aerobic Capacity ◽  
Mixed Models ◽  
Rugby League ◽  
Evidence Base ◽  
Jump Height ◽  
Lower Body ◽  
Body Strength ◽  
Lower Body Strength ◽  
Lower Body Power ◽  
Super League

Participation in women's rugby league has been growing since the foundation of the English women's rugby league Super League in 2017. However, the evidence base to inform women's rugby league remains sparse. This study provides the largest quantification of anthropometric and physical qualities of women's rugby league players to date, identifying differences between positions (forwards & backs) and playing standard (Women's Super League [WSL] vs. International). The height, weight, body composition, lower body strength, jump height, speed and aerobic capacity of 207 players were quantified during the pre-season period. Linear mixed models and effects sizes were used to determine differences between positions and standards. Forwards were significantly (p < 0.05) heavier (forwards: 82.5 ± 14.8kg; backs: 67.7 ± 9.2kg) and have a greater body fat % (forwards: 37.7 ± 6.9%; backs: 30.4 ± 6.3%) than backs. Backs had significantly greater lower body power measured via jump height (forwards: 23.5 ± 4.4cm; backs: 27.6 ± 4.9cm), speed over 10m (forwards: 2.12 ± 0.14s; backs: 1.98 ± 0.11s), 20m (forwards: 3.71 ± 0.27s; backs: 3.46 ± 0.20s), 30m (forwards: 5.29 ± 0.41s; backs: 4.90 ± 0.33s), 40m (forwards: 6.91 ± 0.61s; backs: 6.33 ± 0.46s) and aerobic capacity (forwards: 453.4 ± 258.8m; backs: 665.0 ± 298.2m) than forwards. Additionally, international players were found to have greater anthropometric and physical qualities in comparison to their WSL counterparts. This study adds to the limited evidence base surrounding the anthropometric and physical qualities of elite women’s rugby league players. Comparative values for anthropometric and physical qualities are provided which practitioners may use to evaluate the strengths and weaknesses of players, informing training programs to prepare players for the demands of women's rugby league.

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