Understanding the relative contribution of technical and tactical performance to match outcome in Australian Football

ABSTRACT

The aim of this study was to assess if tactical and technical performance indicators (PIs) could be used in combination to model match outcomes in Australian Football (AF). A database of 101 technical PIs and 14 tactical PIs from every match in the 2009–2016 Australian Football League (AFL) seasons was merged. Two outcome measures Win-loss and Score margin were used as dependent variables. The top 45 ranked technical and tactical PIs from a feature selection process were used to model match outcome using decision tree and Generalised Linear Models (GLMs). Of the top 45 selected features, this included seven tactical PIs. The Win-loss-based Decision tree model achieved a classification accuracy of 89.0% and GLM 93.2%. A Score margin-based GLM achieved a root mean squared error (RMSE) of 6.9 points. A combined approach to the classification of match outcomes provided no improvement in model accuracy compared with previous literature. However, this study has established the relative importance of technical and tactical measures of performance in relation to successful team performance in AF.     

Anticipation by basketball defenders: An explanation based on the three-dimensional inverted pendulum model

Abstract

We previously estimated the timing when ball game defenders detect relevant information through visual input for reacting to an attacker's running direction after a cutting manoeuvre, called cue timing. The purpose of this study was to investigate what specific information is relevant for defenders, and how defenders process this information to decide on their opponents' running direction. In this study, we hypothesised that defenders extract information regarding the position and velocity of the attackers' centre of mass (CoM) and the contact foot. We used a model which simulates the future trajectory of the opponent's CoM based upon an inverted pendulum movement. The hypothesis was tested by comparing observed defender's cue timing, model-estimated cue timing using the inverted pendulum model (IPM cue timing) and cue timing using only the current CoM position (CoM cue timing). The IPM cue timing was defined as the time when the simulated pendulum falls leftward or rightward given the initial values for position and velocity of the CoM and the contact foot at the time. The model-estimated IPM cue timing and the empirically observed defender's cue timing were comparable in median value and were significantly correlated, whereas the CoM cue timing was significantly more delayed than the IPM and the defender's cue timings. Based on these results, we discuss the possibility that defenders may be able to anticipate the future direction of an attacker by forwardly simulating inverted pendulum movement.     

Coaching competency and satisfaction with the coach: A multi-level structural equation model

Abstract

The purpose of this initial predictive validity study was to determine the ability of measures derived from the Athletes' Perceptions of Coaching Competency Scale II – High School Teams (APCCS II-HST) to predict satisfaction with the head coach. Specification of the statistical model was informed by the mediational model of coach–athlete interactions. The technical quality of the satisfaction measure was evaluated before testing the predictive validity of the coaching competency measures. Data were collected from athletes of seven sports. Athlete observations (N = 748) were clustered within teams (G = 74). Multi-group confirmatory factor analyses (CFA) provided evidence for factorial invariance of a reduced version of the satisfaction measure by athlete gender. Multi-level CFA provided evidence of model–data consistency for a reduced version of the satisfaction measure. Multi-level structural equation modelling provided evidence for the ability of latent coaching competency to positively predict latent satisfaction at both the athlete level (technique competency and motivation competency) and the team level (coaching competency) and for close model–data fit. Implications of this study include: that the APCCS II-HST should be viewed as a replacement for the Coaching Competency Scale when the intended population is appropriate; a preliminary multi-level measurement model for satisfaction with one's coach that should be considered as a potential starting point in subsequent studies; and empirical support for a key relationship proposed in the mediational model of coach–athlete interactions.     

层次分析法在人才招聘中的应用研究

目的探讨层次分析法在人才招聘中的应用.方法采用层次分析法（AHP）,将人的主观判断用数量形式表达和处理.结果采用AHP对人才招聘问题进行了研究与讨论,利用AHP法得出应聘人员对各工作类别的权重,通过建立最优分配模型,给出了按需择优录用分配方案.结论层次分析法可以对人才招聘中择优录用的分配方案给出一种好的方法.     

Influences affecting the soil-water characteristic curve

INTRODUCTION The soil-water characteristic curve (SWCC) gives the relationship between the amount of water in the soil (i.e. gravimetric or volumetric water content) and soil suction (i.e. matric suction at low suction and total suction at high suction). Many properties of a partially saturated soil such as the coefficient of permeability, shear strength and volume strain, pore size distribution, the amount of water contained in the pores at any suction, can be obtained from the SWCC. …     

The probability distribution for a biased spinner

This article advocates biased spinners as an engaging context for statistics students. Calculating the probability of a biased spinner landing on a particular side makes valuable connections between probability and other areas of mathematics.     

Self‐efficacy,school resources,job stressors and burnout among Spanish primary and secondary school teachers: a structural equation approach

This study examines the relationship between school resources, teacher self‐efficacy, potential multi‐level stressors and teacher burnout using structural equation modelling. The causal structure for primary and secondary school teachers was also examined. The sample was composed of 724 primary and secondary Spanish school teachers. The changes occurring in the Spanish teacher role in the last decade were taken into account to select job stressors. The results obtained revealed that external (school support resources) and internal (management classroom self‐efficacy and instructional self‐efficacy) coping resources have a negative and significant effect on job stressors. In turn, job stressors have a positive and significant effect on teachers’ burnout considering it as both a unidimensional and multidimensional construct. Furthermore, the hypothesised structure of burnout dimensions revealed that emotional exhaustion plays a key role in explaining Spanish school teachers’ burnout. Practical implications of these findings are discussed.     

Parametric design of a part with free-form surfaces

INTRODUCTION A 3D solid model is used in various processes such as design, engineering evaluation, drafting, manufacturing, and so on. It is a time-consuming and skill-required job to create a complicated 3D solid model. Most commercial CAD tools support func- tions to generate engineering drawings from solid models automatically. However, adjusting layouts, dimensioning, and inserting annotations are required and they are tedious and time-consuming work. Most current CAD/CAM/CAE so…     

水墨写意画造型特点分析

中国画的造型方式有别于其他画种,既不追求绝对的写实,又不主张脱离真实物象的过分夸张变形,而是力求在尊重客观对象的基础上,对形象进行适当的处理,使所表现的形象更加符合画家的主观意图,更加生动,更具表现力。“意象造型”是水墨写意画所采用的基本造型手段,也是中国画造型的显著特征。     

试论数学在现代经济学中的作用

随着经济学的发展,用数学分析和求解问题已成为对各经济领域进行研究,从而获得最佳解决方案的必要手段,如经济指标分析、金融市场风险评估,效益的合理分配、生产成本控制等都离不开数学模型的建立与求解,数学在经济学中的运用不断扩展,已成为经济学中最重要的方法之一,是经济理论研究取得突破的重要工具。