The changing shape characteristics associated with success in world-class sprinters

Abstract

The aims of this study were to identify whether relative shape and size characteristics of world-class sprinters have changed over time, and whether any anthropometric parameters characterize the most successful world-class sprinters. The results suggest that body mass index, reflecting greater muscle mass rather than greater adiposity, is an important factor associated with success in both male and female world-class sprinters over time. However, in female athletes the reciprocal ponderal index (RPI) has emerged as a more important indicator of success over several decades, with taller, more linear sprinters achieving greater success, as measured by sprint speed. In male sprinters it is only in the most recent decade that RPI has emerged as an important predictor of success. We speculate that the prominence of the RPI and an ectomophic somatotype being typical of the most successful world-class sprinters might be explained, in part, by the influence of stride length on sprint speed. In conclusion, these results suggest that coaches, selectors, and sports scientists should consider body shape when selecting potential athletes for sprint events, encouraging more linear athletes with a high RPI.     

Quantitative assessment of the serve speed in tennis

A method is presented for assessing the serve speeds of tennis players based on their body height. The research involved a sample of top world players (221 males and 215 females) who participated in the Grand Slam tournaments in 2008 and 2012. The method is based on the linear regression analysis of the association between the player’s body height and the serve speed (fastest serve, average first-serve, and second-serve speed). The coefficient of serve speed (CSS) was calculated as the quotient of the measured and the theoretical value of the serve speed on a regression line relative to the player’s body height. The CSS of >1, 1 and <1 indicate above-average, average, and below-average serve speeds, respectively, relative to the top world tennis players with the same body height. The CSS adds a new element to the already existing statistics about a tennis match, and provides additional information about the performance of tennis players. The CSS can be utilised e.g. for setting the target serve speed of a given player to achieve based on his/her body height, choosing the most appropriate match strategy against a particular player, and a long-term monitoring of the effectiveness of training focused on the serve speed.     

中外优秀女子网球运动员竞技年龄特征比较分析

采用文献资料法、数理统计法、逻辑归纳法等研究方法对中外20名优秀女子网球运动员的竞技年龄特征进行比较分析,发现:中外优秀女子网球运动员在启蒙训练年龄上的差异并不显著;但是外国优秀女子网球运动员转为职业选手的年龄较早,所以其成为职业选手的年限也较长。中国优秀女子网球运动员之间的现役年龄的分布较为离散,中国十名优秀女子网球运动员的现役年龄差异大于国外十名优秀女子网球运动员的现役年龄差异;并且中国优秀女子网球运动员达到最高竞技水平的年龄比国外优秀女子网球运动员达到最高竞技水平的年龄晚。     

A notational analysis of elite tennis strategy

A notational analysis of singles events at all four Grand Slam tournaments between 1997 and 1999 was conducted to determine the influence of the sex of the player and court surface on elite tennis strategy. Rallies of 7.1 +/- 2.0 s in women's singles were significantly longer than those in men's singles (5.2 +/- 1.8 s; P < 0.001). Rallies of 6.3 +/- 1.8 s at the Australian Open, 7.7 +/- 1.7 s at the French Open, 4.3 +/- 1.6 s at Wimbledon and 5.8 +/- 1.9 s at the US Open were recorded. Rallies were significantly longer at the French Open than at any other tournament (P< 0.05) and significantly shorter at Wimbledon than at any other tournament (P< 0.05). In women's singles, 52.8 +/- 12.4% of points were baseline rallies, significantly more than in men's singles (28.6 +/- 19%; P < 0.001). The proportion of baseline rallies played at the French Open (51.9 +/- 14.2% of points) was significantly greater than at the Australian Open (46.6 +/- 12.5%), Wimbledon (19.7 +/- 19.4%) and the US Open (35.4 +/- 19.5%; P < 0.05). The results show that both the sex of the player and surface of the court have a significant influence on the nature of singles tennis at Grand Slam tournaments.     

The most important points in grand slam singles tennis

A computerized data management system was used to enter details of points played in 252 tennis matches from the men's and women's singles events of all four Grand Slam tournaments over a 2-year period. A supplementary data analysis system was developed to determine the proportion of points won by each player on serve at each game score from love all to deuce as well as the proportion of games the player went on to win from each score. Analysis of the 43 matches in which both players served at each score from love all to deuce revealed that the proportion of points won by the server was not significantly influenced by score, F(15, 495) = 0.8, p > .05. A further analysis of the 175 matches consisting of at least 100 points revealed that the proportion of points won by the superior player was not significantly influenced by gender, F(1, 165) = 0.1, p > .05, or surface, F(3, 165) = 0.1, p > .05. However, the proportion of points won when serving was significantly greater in men's singles than women's singles, F(1, 165) = 69.7, p < .001, R2 = .30. Surface also had a significant influence on the proportion of points won when serving, F(3, 165) = 8.1, p < .001, R2 = .13, with a significantly greater proportion of points won when serving by both winning and losing players at Wimbledon than at the Australian and French Opens, p < .05. This suggests that gender and surface should be accounted for when determining the importance of points in Grand Slam tennis.     

A notational analysis of elite tennis strategy

A notational analysis of singles events at all four Grand Slam tournaments between 1997 and 1999 was conducted to determine the influence of the sex of the player and court surface on elite tennis strategy. Rallies of 7.1 ± 2.0 s in women's singles were significantly longer than those in men's singles (5.2 ± 1.8 s P < 0.001). Rallies of 6.3 ± 1.8 s at the Australian Open, 7.7 ± 1.7 s at the French Open, 4.3 ± 1.6 s at Wimbledon and 5.8 ± 1.9 s at the US Open were recorded. Rallies were significantly longer at the French Open than at any other tournament ( P < 0.05) and significantly shorter at Wimbledon than at any other tournament ( P < 0.05). In women's singles, 52.8 ± 12.4% of points were baseline rallies, significantly more than in men's singles (28.6 ± 19% P < 0.001). The proportion of baseline rallies played at the French Open (51.9 ± 14.2% of points) was significantly greater than at the Australian Open (46.6 ± 12.5%), Wimbledon (19.7 ± 19.4%) and the US Open (35.4 ± 19.5% P < 0.05). The results show that both the sex of the player and surface of the court have a significant influence on the nature of singles tennis at Grand Slam tournaments.     

Tennis superstars: The relationship between star status and demand for tickets

Akin to other sports, professional tennis is urged to adopt a consumer-centred strategy and understand the influence of the star status of elite players on demand for its core product. Measuring the impact that tennis players have on demand for match attendance remains a key element towards achieving that goal. Using data from the Australian Open ticket sales, the authors demonstrate how individual players have influenced stadium attendance at the Grand Slam. Findings indicate that some players are associated with a strong positive impact on demand for tickets, above and beyond their performance ratings, reflecting their value to the Australian Open. The authors discuss how this star status can be used to inform business decisions related to tournament management, match scheduling, and determining player appearance fees, to ultimately drive better commercial outcomes and deliver a world-class sporting event. The findings have implications for tournament organisers, player managers and those that market player activities.     

中外优秀女子网球运动员的基础形态特征比较分析

本文对中国和世界优秀女子网球运动员的身高、体重、克托莱指数、年龄和体型等基础形态指数进行了统计分析和比较，结果表明：我国的女子网球运动员和世界的优秀女子网球运动员在基础形态方面存在着差距，建议应尽快完善、构建与世界优秀女子网球运动员身体形态模式相适应，而又符合中国国情的女子网球运动员选材模式和评价标准。进而，又对世界和中国的优秀女子网球运动员的身高和体重指数进行了回归分析，构建了回归模型，旨在为女子网球运动选材与运动训练提供理论参考。     

The changing shape characteristics associated with success in world-class sprinters

The aims of this study were to identify whether relative shape and size characteristics of world-class sprinters have changed over time, and whether any anthropometric parameters characterize the most successful world-class sprinters. The results suggest that body mass index, reflecting greater muscle mass rather than greater adiposity, is an important factor associated with success in both male and female world-class sprinters over time. However, in female athletes the reciprocal ponderal index (RPI) has emerged as a more important indicator of success over several decades, with taller, more linear sprinters achieving greater success, as measured by sprint speed. In male sprinters it is only in the most recent decade that RPI has emerged as an important predictor of success. We speculate that the prominence of the RPI and an ectomophic somatotype being typical of the most successful world-class sprinters might be explained, in part, by the influence of stride length on sprint speed. In conclusion, these results suggest that coaches, selectors, and sports scientists should consider body shape when selecting potential athletes for sprint events, encouraging more linear athletes with a high RPI.     

四大网球公开赛女子单打冠军年龄特征对我国运动员培养的启示

对公开赛时代至今的四大网球公开赛女子单打冠军的年龄特征分析,探讨冠军和首次夺冠的运动员年龄特征,旨在为中国女子网球运动员的培养提供参考。结论显示：冠军年龄结构特征正态分布效果较好,已经具备了相对稳定的显著特征,形成了各具特征的3个年龄段——16-18岁的低龄段、19-28岁主体年龄段和29-33岁的大龄段;首冠年龄分析揭示出不同实力球员的竞技发展期;参照年龄特征发现目前中国女子网球单打运动员的技能水平高峰期显现较晚。     

The role of facial attractiveness in tennis TV-viewership

Social sciences, anthropology, psychology, and economics researchers have shown various effects of physical attractiveness. In this study, the authors analyze 622 live tennis matches from 66 Grand Slam tournaments between 2000 and 2016, examining the relationship between facial attractiveness, measured by tennis players’ facial symmetry, and TV-viewership. Results indicate that facial symmetry plays a positive role for female matches while there is no significant effect for male matches. The effect persists in several subsample regressions and robustness checks. The findings have important implications for managers in the field of sports. While public broadcasters have a public service function and therefore should be careful in exploiting consumer biases to avoid reinforcing non-sports taste-based discrimination types. Commercial broadcasters and media institutions with solely profit-maximizing objectives will likely exploit consumer biases.     

An examination of the importance of performances in youth and junior competition as an indicator of later success in tennis

Talent identification at a young age is deemed essential for many national sporting organisations to increase the chances of success for their players on the international stage. Talent identification methods can be imprecise and national tennis associations and coaches often identify talent based on performances at youth tournaments and junior rankings. However, not much is known about the relationship between the international competition performances of young tennis players and later success. This relationship is explored in this study using comparisons based on: (a) the results of 3521 players at U14 youth tournaments; (b) the rankings of 377 junior players (U18) by the International Tennis Federation; (c) the rankings of 727 professional male players by the Association of Tennis Professionals; and (d) the rankings of 779 professional players by the Women's Tennis Association. Junior performances (U18) and performances at youth tournaments (U14) appear to have a low success rate in predicting later success. No distinct age was found at which players should start to perform in order to be successful at the professional level. It is concluded that even though good performances at young ages increase athletes’ chances to become elite players, they are not a precondition for achieving later success. Therefore, this study informs talent scouts, sport development officers, coaches and high performance managers of the role that performances at international youth competitions may play in talent identification in tennis.     

中外优秀男子网球运动员竞赛成败归因的研究

对网球运动成败归因的科学研究不仅为丰富运动训练学、运动心理学理论提供实证依据,对网球运动训练的科学化也具有借鉴意义。采用质性研究法以男子网球运动员在大赛后的访谈材料为研究对象,对当前优秀男子网球运动员竞赛成败归因进行详细的研究、分析。结果表明,优秀男子网球运动员的成败基本归因是一致的。从自由节点和相应的总参考点数来看,国内、外优秀男子网球运动员对于失败归因不同。从相应节点比例来看,成功时,国外运动员的归因更加细致和多元化,而失败时,国内男子网球运动员的归因更多。     

我国优秀女子乒乓球和羽毛球运动员身体形态特征的研究

对我国优秀乒乓球女子运动员、羽毛球女子运动员的身体形态指标、体型特点进行比较分析,结果发现很多身体形态指标有非常显著的差异:乒乓球运动员四肢围度为主要因子,特别是上臂围度的因子载荷为最大;而羽毛球运动员长度为主要因子。     

Evaluation of elite table tennis players' technique effectiveness

Abstract

This study constructed a technique effectiveness evaluation formula for table tennis players based on the relationship between the scoring rate and usage rate of techniques and established the evaluation criteria through the examination of 224 matches of the world's top 35 players. It also built a competition performance formula with the score difference theory for the exploration of the correlation between player technique effectiveness and competition performance. The results showed the three indices – the technique effectiveness of the first and third strokes (TE_1,3), the second and fourth strokes (TE_2,4) and the after fourth strokes (TE_>4) – could help better evaluate the technique effectiveness of elite players. The comparative analysis of Chinese elite table tennis players and players from other countries and regions revealed that Chinese players as a whole were “excellent” in all the examined techniques except in the male's “first and third strokes”; while players from other countries and regions were overall “general”. The case analysis of two world top players further indicated that correlation analysis of technique effectiveness and competition performance could help identify the technique indices highly correlated with player competition performance.     

网球大满贯单打运动员身体形态及相关年龄特征分析

为了对网球大满贯单打运动员的身体形态以及运动生涯中相关年龄特征有一个清楚的了解,以期对以后从事网球运动的运动员的选材、训练以及运动生涯的宏观把握提供理论及数据参考,运用文献资料、数理统计法等对其身体形态指标以及运动生涯中相关年龄特征分析后得知,网球大满贯单打男子和女子球员的身高、体重、克菜托指数三项指标都具有稳定的正态分布特征;男子和女子球员在学球年龄和首获大满贯年龄上不存在显著性差异（P〉0．05）;在转入职业赛年龄和首获职业赛冠军年龄上却存在显著性差异（P〈0．05）;而在职业生涯冠军总数及职业年限上不存在显著性差异（P〉0．05）。     

Clustering tennis players’ anthropometric and individual features helps to reveal performance fingerprints

Abstract

The study was aimed to explore distinct players’ groups according to their anthropometric and individual features, and to identify the key performance indicators that discriminate player groups. Match statistics, anthropometric and personal features of 1188 male players competing during 2015–2017 main draw Grand Slam singles events were collected. Height, weight, experience, handedness and backhand style were used to automatically classify players into different clusters through unsupervised learning model. Afterwards, 29 match variables were analysed through MANOVA and discriminant analysis in order to evaluate the different match performance among player groups and to identify the key performance indicators that best differentiate player clusters in each Grand Slam. The analysis revealed the existence of four clusters, they were classified as Big-sized Right Two-handed Players (n?=?387), Medium-sized Right One-handed Players (n?=?265), Small-sized Right Two-handed Players (n?=?414), and Left Two-handed Players (n?=?122). Serve, winner, net and physical performance-related indicators (Structure Coefficient?≥?|0.30|) were showed to be the maximum contributors to the group separation. Left-handed players were the most homogenous group in performance. Taller players outperformed their peers in all Slams except for Roland Garros, where left-handed players demonstrated certain advantage playing on slow-pace surface. In Wimbledon and US Open, Medium-sized Right One-handed Players showed better net and physical performance. The advantage of left-handed player is over-represented at elite level. Current findings promote a better understanding of match-play from distinct player groups and offer information on evaluating contextual variability for achieving better performances.     

Expectancy effects in tennis: The impact of opponents' pre-match non-verbal behaviour on male tennis players

Abstract

In this study, we examined the impact of a male opponent's pre-match body language and clothing (general vs. sports-specific) on how his performances were judged by an observer. Forty male tennis players viewed videos of a male target tennis player warming up and then observed playing footage of the target. Each participant viewed the target player warming up displaying one of four combinations of body language and clothing (positive body language/tennis-specific clothing; positive body language/general sportswear; negative body language/tennis-specific clothing; negative body language/general sportswear). Participants rated the performance of the tennis player and gave their perceptions of the likely outcome of a tennis match with the target player. Analyses of variance indicated that clothing and body language had an interactive effect on both outcome expectations and ratings of performance. The findings support the contention that the initial impressions athletes form of their opponents can influence the way in which they judge the performances of opponents and their perceived likelihood of success against the same opponents.     

A machine learning approach for automatic detection and classification of changes of direction from player tracking data in professional tennis

ABSTRACT

The purpose of this study was to develop an automated method for identifying and classifying change of direction (COD) movements in professional tennis using tracking data. Three sport science and strength and conditioning experts coded match-play footage of nineteen professional tennis players (9 male and 10 female) from the Australian Open Grand Slam for COD of medium and high intensity. A total of 1,494 changes were identified and aligned with 2D player position sampled at 25 Hz based on camera tracking data. Several machine learning classifiers were trained and tested on a set of 1,128 time-motion features. A random forest algorithm was found to have the best out-of-sample performance, classifying medium and high intensity changes with an F1-score of 0.729. This research offers a novel and applicable way for utilising player tracking data and machine learning techniques to automatically identify and classify COD movements in professional tennis.     

Changes in body mass,stature and BMI in South African elite U18 Rugby players from different racial groups from 2002–2012

The purpose of this study was to determine whether there are differences between racial groups for body mass, stature and body mass index (BMI) in South African elite U18 rugby players and whether there were significant changes in these measurements between 2002 and 2012. Self-reported body mass and stature were obtained from U18 players (n = 4007) who attended the national tournament during this period. BMI was calculated for each player.White players were 9.8 kg heavier than black players, who were 2.3 kg heavier than coloured players (P < 0.0001). The body mass of all groups increased from 2002 to 2012 (P < 0.0001). White players were 7.0 cm taller than black players who were 0.5 cm taller than coloured players (P < 0.0001). Players’ stature measurements did not change significantly during the study period. The average BMI of white players was 0.9 kg·m^?2 greater than black players who were on average 0.7 kg·m^?2 greater than coloured players (P < 0.0001). The BMI of all groups changed similarly over the study period. The body mass, stature and BMI of elite under-18 rugby players in South Africa were significantly different between racial groups. This has implications for transforming the game to make it representative of the South African population.