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As we all know, momentum plays a crucial role in ball game. Based on the 2023 Wimbledon final data, this paper investigated momentum in tennis. Firstly, we initially trained a decision tree regression model on reprocessed data for prediction, and established the CBRF model based on CatBoost regression and random forest regression models to obtain prediction data. Secondly, significant non-zero autocorrelation coefficients were found, confirming the correlation between momentum and success. Thirdly, Based on these key factors, we proposed winning strategies for the players, conducted predictive analyses for six specific time intervals of the game. At last, by implementing these models to women's matches, championships, matches on different surfaces, the results demonstrated that the models have effective generalization ability. [ABSTRACT FROM AUTHOR]

While previous studies have focused on the value of the endorsement contracts at the moment they are signed, the performance during the contract has drawn limited attention, and the few studies focusing on this period have produced inconclusive results. To fill this gap, we hypothesize that the tournament type and the athlete's level of sports elitism can influence this "sport results-business performance" relationship. The inclusion of the tournament type fills a gap in the literature as most studies have examined the potential effects of endorsement strategies without observing the different levels of tournaments within a particular sport. Guided by brand equity theory and equity theory, we argue that while a greater prize won corresponds to higher stock returns, there is a certain point of "sports elitism" on part of the athlete, after which a greater prize leads to lower stock returns. Empirical results from tennis tournaments support these arguments. [ABSTRACT FROM AUTHOR]

(1) Background: The analysis of women's tennis performance has not been extensively explored by the scientific community, necessitating further research to understand the tactical actions occurring in matches. This research aimed to examine the chance of winning a point in professional women's tennis based on the key variables that influence performance in the sport. (2) Methods: Data from 3239 points were examined across three distinct court surfaces, sourced from the final rounds (starting with the quarterfinals) of three Grand Slam tournaments in the 2021 season. An observational methodology was employed, using various analysis techniques: descriptive and chi-square analyses, with a significance level of p < 0.05. (3) Results: The probability of winning a point on the first serve was 61% on clay, 70% on grass, and 69% on hard courts. For second serves, the probability of winning the point varied between 55% and 57%, depending on the court surface. Additionally, the majority of points, ranging from 70% to 71%, concluded with short rallies, involving one to four shots. On clay courts, the server won up to 65% of points with a first serve and a short rally, while the success rate increased to 75% on both grass and hard courts. For medium-length rallies (5–8 shots), the probability of winning the point dropped to 55–57%. The point outcome (winner, forced error, and unforced error) varied according to court surface, serve type, and rally length. (4) Conclusions: Descriptive data from this research on the probability of winning a point could assist coaches and players in developing match strategies. [ABSTRACT FROM AUTHOR]

We propose an alternative design for tournaments that use a preliminary stage, followed by several rounds of single elimination play. The conventional "bracket" design of these tournaments suffers from several deficiencies. Specifically, various reasonable performance criteria for the tournament are not satisfied, there is an unnecessary element of luck in the matchups of players, and there are situations where players have an incentive to shirk. To address all these issues, we allow higher ranked players at the single elimination stage to choose their next opponent sequentially at each round. We allow each player's ranking either to remain static, or to improve by beating a higher ranked player (Guyon, J. 2022. "Choose your opponent": a new knockout design for hybrid tournaments. J. Sports Anal. 8: 9–29). Using data from 2215 men's professional tennis tournaments from 1991 to 2017, we demonstrate the reasonableness of the results obtained. We also perform sensitivity analysis for the effect of increasing irregularity in the pairwise win probability matrix on three traditional performance measures. Finally, we consider strategic shirking behavior at both the individual and group levels, and show how our opponent choice design can mitigate such behavior. Overall, the opponent choice design provides higher probabilities that the best player wins and also that the two best players meet, and reduces shirking, compared to the conventional bracket design. [ABSTRACT FROM AUTHOR]

Table tennis players need to have tactical awareness, that is, to choose the most appropriate tactical strategy to deal with the opponent's situation and the game situation. But in practice, many athletes tend to neglect the training of tactical awareness, resulting in a disconnect between training and competition. In order to solve this problem, this paper introduces a spatial dynamic image planning method based on wearable optoelectronic devices, and applies it to the tactical simulation of table tennis match. By analyzing the characteristics and demands of table tennis competition, an optical sensing system is designed and integrated into wearable devices. The system uses optical sensors to capture the position and movement trajectory of ping-pong balls in real time, and carries out real-time image processing and analysis based on this information. In the process of tactical simulation, the system can predict the opponent's tactical intention according to the position and trajectory of the ping-pong ball, and give corresponding coping strategies. The experimental results show that the system achieves good results in both accuracy and real-time performance. The application of tactical optimization model in table tennis competition will help to improve the competitive level of athletes and promote the development of table tennis. [ABSTRACT FROM AUTHOR]

While deep learning has been widely used for video analytics, such as video classification and action detection, dense action detection with fast-moving subjects from sports videos is still challenging. In this work, we release yet another sports video benchmark P2ANet for Ping Pong-Action detection, which consists of 2,721 video clips collected from the broadcasting videos of professional table tennis matches in World Table Tennis Championships and Olympiads. We work with a crew of table tennis professionals and referees on a specially designed annotation toolbox to obtain fine-grained action labels (in 14 classes) for every ping-pong action that appeared in the dataset, and formulate two sets of action detection problems—action localization and action recognition. We evaluate a number of commonly seen action recognition (e.g., TSM, TSN, Video SwinTransformer, and Slowfast) and action localization models (e.g., BSN, BSN++, BMN, TCANet), using P2ANet for both problems, under various settings. These models can only achieve 48% area under the AR-AN curve for localization and 82% top-one accuracy for recognition since the ping-pong actions are dense with fast-moving subjects but broadcasting videos are with only 25 FPS. The results confirm that P2ANet is still a challenging task and can be used as a special benchmark for dense action detection from videos. We invite readers to examine our dataset by visiting the following link: https://github.com/Fred1991/P2ANET. [ABSTRACT FROM AUTHOR]

To become an elite table tennis player, aside from continually practicing, players must know their strengths and weaknesses to plan their strategy beforehand and increase their winning rate. The main problems with previous research were that the data collected were incomplete and imprecise. To address these problems, we established "The Intellectual Tactical System in Competitive Table Tennis", using video analysis to collect competitive data. Additionally, we proposed a machine learning method using a combination of feature-selection and association rules to discover interesting rules from the data. The international matches of the Taiwanese table tennis single player Yun-Ju Lin were used as research samples by applying 3 S (speed, spin, spot) theory to collect and analyze data. The critical factors and scenarios were analyzed to identify the winning tactical models. The results of this study may provide useful suggestions for Yun-Ju Lin on training and building tactics in competitions. The similar approach may be essential for elite players and coaches to have appropriate tactical analysis. [ABSTRACT FROM AUTHOR]

Junior tennis players travel a lot to play tennis tournaments; this causes them to spend a lot of time away from their homes and disrupts their training, which could reduce their performance and increase the risk of injury. The purpose of this study was to analyze the changes in physical performance and body composition after a six-week international tour in young Chilean female tennis players. Thirty young female tennis players (15.4 ± 0.6) participated in this study. Body weight, skinfolds, and perimeters were measured. Body fat percentage (BFP) and skeletal muscle mass (SMM) were calculated. For physical performance, 5 m sprint, the 505 with stationary start test (505 test), the pro-agility test, countermovement jump (CMJ), and medicine ball throw (MBT) were evaluated. The results show a significant increase in BFP and decrease in SMM (p < 0.01; d = −0.18 and 0.19, respectively). In terms of physical performance, 5 m sprint, the 505 test (p < 0.01; d = −0.95 and −0.95, respectively), CMJ, MBT, and HJ significantly decreased post-tour (p < 0.05; d = 0.96, 0.89 and 0.47, respectively). We conclude that, after a six-week international tour, there were changes in body composition and a significant decrease in 5 m sprint, the 505 test, CMJ, and MBT. [ABSTRACT FROM AUTHOR]

Research on anticipation in sports has generally focused on the role of visual information. Only recently, effects of other modalities, such as auditory information have been considered. For instance, several studies highlight the importance of auditory information from racket-ball contact sounds and grunting in tennis on the anticipation of ball trajectories (Cañal-Bruland et al., 2018; Müller et al., 2019), with louder sounds yielding longer anticipated trajectories. However, findings were usually obtained in laboratory settings, without the time constraints characteristic of tennis matches. Therefore, two experiments tested whether these findings generalise to more ecologically valid settings. Participants responded to a series of video clips of tennis rallies (occluded after racket-ball contact) shown on a tablet with sound intensity of players' grunting experimentally manipulated (muted, low, original, high) within participants. To introduce time constraints, Experiment 1 required them to react by moving their finger to the ball's anticipated landing location just in time with the ball's touchdown. In contrast to previous findings, grunt intensity neither affected the ball's anticipated landing position nor the movement trajectory. Experiment 2 mirrored Experiment 1, except that participants responded without time pressure by pointing at the ball's estimated landing position. Here results replicated the well-established findings of previous studies (e.g., Müller et al., 2019; louder grunts yielding longer anticipated trajectories), ruling out that the lack of effects in Experiment 1 was caused by specifics of the employed stimuli. The appropriateness of the employed temporal constraints in light of ecological validity and implications for future research are discussed. [ABSTRACT FROM AUTHOR]

In this study, we tested the theory of angles that was proposed almost a century ago by the tennis player Henri Cochet. This theory proposes that expert tennis players should position themselves on the bisector of the angle of the opponent's possibilities in order to optimize shot return, suggesting a geometric occupation of the court relative to the opponent's affordances; namely what he/she is capable of doing. We tested this hypothesis by analysing player and ball positioning data from professional tennis matches recorded with a Hawk-Eye system. We compared this hypothesis with two alternative computational and probabilistic hypotheses which would consist in positioning oneself on the average or the median of the shots usually played from a given location. The results show that expert tennis players apply the principles of the theory of angles and thus confirm Henri Cochet's intuition. That is, for lateral court positioning, a geometric strategy is deemed optimal by expert players. It also appears that the more experienced the players are, the more precise their application of this strategy becomes. [ABSTRACT FROM AUTHOR]

The present study examines the validity of the SwingVision application by comparing SwingVision's data to criterion data. Also, we investigated the difference in recording angles of SwingVision (optimal and suboptimal). Six college students played four matches, and every match was recorded from two different angles. After the data collection, recorded videos were analysed by SwingVision and human analysts (criterion). A total of 1065 strokes were analysed in the agreement of SwingVision and human analysts. Cross-tabulation with a column proportion test, Cochran's Q test, and Kappa statistics were utilised to demonstrate the association of categorical variables (stroke, hit depth, hit zone, bounce depth, bounce zone, spin, result) between the three data (i.e. optimal, suboptimal, and criterion). Repeated measures analysis of variance (ANOVA) and Pearson correlation were used to compare speed data. SwingVision data in most variables showed high proportional similarity and percent agreement with criterion data. Additionally, the optimal angle data had much more similar results to the criterion data than the suboptimal data. Therefore, this present study documented that SwingVision is trustworthy, and users should be aware of possible errors derived from angle differences. [ABSTRACT FROM AUTHOR]

This paper aims to propose a table tennis target detection (TD) method based on deep learning (DL) and multi-scale feature fusion (MFF) to improve the detection accuracy of the ball in table tennis competition, optimize the training process of athletes, and improve the technical level. In this paper, DL technology is used to improve the accuracy of table tennis TD through MFF guidance. Initially, based on the FAST Region-based Convolutional Neural Network (FAST R-CNN), the TD is carried out in the table tennis match. Then, through the method of MFF guidance, different levels of feature information are fused, which improves the accuracy of TD. Through the experimental verification on the test set, it is found that the mean Average Precision (mAP) value of the target detection algorithm (TDA) proposed here reaches 87.3%, which is obviously superior to other TDAs and has higher robustness. The DL TDA combined with the proposed MFF can be applied to various detection fields and can help the application of TD in real life. [ABSTRACT FROM AUTHOR]

Introduction: Emotions consist of different components such as the emotional experience, physiological reactions, action tendencies, or emotional expressions. Assessing the relation of these components may help to better understand the role of emotions in sport competitions. Based on the component process model of emotions, the goal of the present study was to assess the relation between emotional experiences and emotional expressions. Methods: Twenty tennis players (7 female) with an average age of 23.10 (SD = 4.88) were taped during competitive tennis matches. Thereafter, in individual meetings, after having watched themselves on the footage at pre-selected points, the players had to indicate whether, immediately after the end of a rally, they had a positive or a negative emotional experience and, in case they had one, rate its intensity. Moreover, based on their observable behavior, the players were also asked to state whether they could recognize a positive or a negative emotional expression and, in case they recognized one, rate its intensity. The occurrence of emotional expressions was additionally rated by two external coders. Using multilevel models, separate analyses were conducted for positive emotions after won points and negative emotions after lost points. Results and discussion: For both positive and negative emotions, the results indicated a positive correlation between emotional experiences and emotional expressions. Moreover, the intensity of emotional experiences could predict the occurrence of an emotional expression rated by both the players or external coders. These insights into the relation between emotional experiences and emotional expressions may help players to more effectively regulate their emotions. [ABSTRACT FROM AUTHOR]

A player's purpose in playing a game is their reason for playing the game in the first place (5-11). From inside the game, successful pure striving players should be playing as if the end of winning this game just was their purpose; that is, as if they were pure achievement players. What distinguishes achievement players from striving players is their motivational orientation toward this goal, what Nguyen stipulates as their I purpose i in playing the game. Keywords: Games; achievement play; striving play; Suits; virtue; ethics; aesthetics EN Games achievement play striving play Suits virtue ethics aesthetics 369 379 11 12/22/21 20211101 NES 211101 In his groundbreaking and fantastic new book, I Games: Agency as Art i , C. Thi Nguyen asks us to see gameplay, and hence the "humorous, the playful, and the ridiculous" ([1], 42), as an important sphere of life that can, under appropriate conditions, develop our capacity as agents. [Extracted from the article]

Due to the large number of frames and low video resolution, tennis match videos cannot accurately identify and extract effective data, which reduces the level of fine analysis of tennis matches. In order to solve the problem of poor detection effect of small targets in tennis video, an automatic detection method of small targets in tennis video based on deep learning is proposed. Non-maximum suppression algorithm is used to determine the position of the target between different adjacent video image sequences, and SVM classifier is used to train a large number of target behaviors. According to the hierarchical structure of dataset annotation, the hierarchical structure of tennis video for deep learning is optimized. The reconstruction algorithm is used to enhance the video image in the input VOC data set and improve the fine segmentation effect of the image. The difference video image is binarized to complete the automatic detection of small targets in tennis video. The experimental results show that the proposed method has high integrity of tennis video information collection, high recognition accuracy and short detection time. [ABSTRACT FROM AUTHOR]

Tennis match performance is often evaluated by a player's internal (heart rate) and external (match analytics) outcomes. Numerous factors could influence these outcomes, including the time of day, which may be advantageous or not depending on a player's chronotype. This study aimed to determine the influence time of day, chronotype and sleep–wake behaviour (SWB) had on internal and external outcomes of tennis matches. Twelve state-level male tennis players, with a mean age of 28 ± 7, stature of 183 ± 7 and body mass of 86.6 ± 17.4 wore an actigraph device and completed a sleep diary for the study duration. Based on rankings, players were paired against the same opponent and completed three tennis matches at 8:00 am, 2:00 pm and 8:00 pm, separated by a minimum of 48 h. Fatigue and chronotype, measured by the Fatigue Severity Scale, Morningness Eveningness Questionnaire and midsleep time, were assessed before matches; motivation, measured by the Intrinsic Motivation Inventory, was assessed after matches. During matches, players wore global positioning systems and heart rate monitors; the match analytics and players' rate of perceived exertion were recorded. Increased unforced errors and decreased winners and forced errors were observed in the evening matches. Decreased total distance and rate of perceived exertion during the second set were found for the evening compared to morning and afternoon matches. Chronotype and sleep–wake behaviour had trivial to weak associations with internal and external outcomes. These results indicate that players and coaches should consider the match times when training for future tournaments. [ABSTRACT FROM AUTHOR]

This study presents an in-depth analysis of the serve in men's singles tennis matches at Wimbledon based on game theory, with the quantitative tool of the stroke performance relevance (SPR) model. This model quantifies tennis tactics more precisely, taking "each stroke" as the observation unit, and it includes scoring, losing points, and sequential information. Unlike traditional methods that consider "each point", the SPR metrics captures the role of specific technical actions throughout the match more comprehensively. While standard serve data like aces and double faults have no significant impact on match outcomes, the serve SPR index does. In a game matrix model with two pure strategy Nash equilibria, both the winner and loser show higher SPR indices than those with fewer equilibria. Winners consistently exhibited a higher serve SPR index, indicating that the two pure strategy Nash equilibria significantly influenced match outcomes on grass courts. This underscores the role of tactical strategies and Nash equilibrium in determining match results, offering scientific and theoretical support for tennis athletes' and coaches' tactics. [ABSTRACT FROM AUTHOR]

In this work, we apply the Logistic Regression (LR) model for predicting the outcome of tennis matches and providing win probability for participating/competing players. Prediction models are classified as machine learning methods, which generate predictions for future scenaria exploiting existing data collections. With the objective to maximize the accuracy of our predictions, we apply the Logistic Regression model under various parameter configurations seeking for an optimal combination of independent variables (features). We present and discuss promising results obtained via the holdout-validation method and the cross-validation method. Furthermore, as a proof of concept of our approach, we designed and implemented a web platform, where users can obtain real-time predictions for tennis matches. Our LR-based framework combined with Artificial Intelligence (AI) can serve as a paradigm in the field of sports analysis for predicting outcomes and evaluating athletic performance. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate the contribution quality of table tennis matches comprehensively and explore the ranking characteristics of evaluation results and the rationality of grading. Through the application of the documentation method, videos, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Rank Sum Ratio (RSR), the contribution quality evaluation index system of table tennis matches was established. After then, the technical and tactical performances of 38 matches between H (anonymous), who is currently highly concerned and active in the international table tennis world from 2018 to 2020 were comprehensively evaluated. According to research results, H had 8 matches with the Ci value > 0.5 in serve rounds, 4 with the Ci value > 0.5 in receive rounds, and 5 with the RSR value > 0.6 in the comprehensive strength. These findings were generally consistent with the final match results. Furthermore, Pearson Correlation showed that the three indicators were significantly correlated with competition performance (CP) (P < 0.01). Each race could be divided into four grades, and there was a very significant difference among them by variance test (F = 60.281, P < 0.01). Meanwhile, SNK pairwise comparison between four grades had statistical significance (P < 0.05). Therefore, researchers could conclude that the combination of TOPSIS and RSR could objectively and accurately reflect the contribution quality of table tennis matches. This method could be promoted and applied in the competition performance evaluation of other net games. [ABSTRACT FROM AUTHOR]

The relative age effect (RAE) has been the subject of many studies, but no relevant literature has discussed the phenomenon of RAE in Chinese tennis. Numerous studies have demonstrated that RAE significantly contributes to brain drain and other occurrences that create inequity. This paper analyzes the birth dates and year-end rankings of all male players (N = 2697) who participated in China's junior tennis tournaments (U12, U14, U16) between 2014 and 2019 and who were selected for China's National Junior Team in 2019 and 2020; the paper classifies the birth dates into quarters and semesters. One of the research objectives of this study is to analyze whether RAE exists in Chinese junior men's tennis and whether RAE exerts an effect on athletes' performance. Differences between the observed and expected birthdate distributions were tested using chi-square statistics, and subsequent calculations were tested using odds ratios. The study found that RAE was present in all Chinese junior male tennis sports groups (p<0.001). The percentages of athletes born in the first half of the year were 56.4% (U12), 60.4% (U14), and 60.4% (U16), and the percentages of those born in the first quarter were 34.1% (U12), 36.4% (U14), and 37.1% (U16). Athletes with birth dates closer to the beginning of the year had a higher probability of achieving excellent athletic performance as a result of RAE, whereas those who were born near the end of the year had a more difficult time achieving strong athletic performance. [ABSTRACT FROM AUTHOR]

Background: Currently, technical and tactical analysis has become an indispensable task for sport in many countries. Many studies analysed players' specific technical and tactical factors, but it is rare to quantitatively analyse the importance of table tennis players' shot effectiveness. This is the first study to propose the new concept of "shot effectiveness model", and the purpose of this study is to explore the structure of the shot effectiveness model for elite table tennis, including the importance degree of shot effectiveness, and the relationship between them. Methods: 258 matches were selected between the top 50 players in the world from 2019 to 2021 as samples. Multiple regression analysis was used to obtain the standard regression coefficients and game simulation, and the total decision coefficient (TDC) was used to evaluate the importance degrees of shot effectiveness (SE) on match results. Results: (1) There was little difference in the importance degree of each shot effectiveness between men and women players. (2) The importance degree of the first and third shots (SE1), the second and fourth shots (SE2), the fifth and after shots (SE3), and the sixth and after shots (SE4) for both men and women players account for approximately 25%, 35%, 22%, and 16% respectively. (3) There was little difference in the importance degree of each shot effectiveness between Chinese women players and women players from other countries and regions with the same importance order of SE2 > SE1 > SE3 > SE4. However, the structure of the shot effectiveness model for men players was quite different from that for women players. (4) There is a compensation effect between shot effectiveness of table tennis players, and the total evaluation score of 12 and 13 is the dividing line for success or failure in both men and women matches. Conclusions: TDC could well reflect the important degrees of each shot effectiveness in various ways on winning probability in table tennis matches. And this study compared the importance of several types of players' performance on the probability of winning a match. In addition, we found that there is a compensation effect between shot effectiveness of table tennis players, and the magnitude of this effect will vary according to the type and level of shot effectiveness. [ABSTRACT FROM AUTHOR]

The history of campaigns against apartheid through sport reveals messy relationships between athletes and social movements, advancing recent debates over the possibilities and constraints of sport politics. The anti-apartheid movement coalesced around a transnational sporting boycott to isolate South Africa, but the American tennis icon Arthur Ashe made a series of visits to compete there in the 1970s. Ashe believed in participation as the primary mechanism for change through sport, only later embracing the boycott. When tennis tournaments and rugby tours brought South Africans to the United States, anti-apartheid organizations mobilized their own confrontational protests to interrupt play. As the growing movement won over athletes and South African propaganda turned toward commercial sport spectacle, the special position that athletes occupied provided leverage. However, their magnified legacy also obscured how resistance to apartheid through sport found success in the first place. Despite the appeal of participation as the natural path of progress, strategies of confrontation often proved more effective in the struggle against apartheid. Questioning the politics of participation and widening the frame to consider confrontation changes our understanding of sport politics, looking beyond individual athletes and bringing everyday people off the sidelines. [ABSTRACT FROM AUTHOR]

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This study adopts a new approach, SHapley Additive exPlanation (SHAP), to diagnose the table tennis matches based on a hybrid algorithm, namely Long Short-Term Memory–Back Propagation Neural Network (LSTM–BPNN). 100 male singles competitions (8535 rallies) from 2019 to 2022 are analyzed by a hybrid technical–tactical analysis theory, which hybridizes the double three-phase and four-phase evaluation theories. A k-means cluster analysis is conducted to classify 59 players' winning rates into three levels (high, medium, and low). The results show that LSTM–BPNN has excellent performance (MSE = 0.000355, MAE = 0.014237, RMSE = 0.018853, and R 2 = 0.988311) compared with six typical artificial intelligence algorithms. Using LSTM–BPNN to calculate the SHAP value of each feature, the global results find that the receive-attack and serve-attack phases of the ending match have essential impacts on the mutual winning probabilities. Finally, case applications show that the SHAP can directly obtain each feature importance on one or more matches, which is more objective and reliable than the traditional simulation method. This research explores an innovative way to understand and analyze matches, and these results have implications for the performance analysis of table tennis and related racket sports. [ABSTRACT FROM AUTHOR]

The topspin forehand is the most frequent and effective shot in top-level table tennis matches. The present study assesses the biomechanical differences in the topspin forehand stroke technique when the incoming ball is in different rotations. Eight national level-1 male table tennis athletes (176.6 ± 4.8 cm, 70.8 ± 6.6 kg, 20.9 ± 2.4 yr) performed two kinds of techniques—topspin forehand strokes against topspin (AT) and against backspin (AB) balls, respectively. The kinematic parameters of their bodies and rackets were calculated. Meanwhile, the force plates analyzed their lower limb moments through inverse dynamics. Paired t-test and non-parametric paired t-test mapping were used to assess the differences between the two conditions. Their center of gravity (COG) vertical distance, elbow flexion, thorax–pelvis flexion, and knee flexion angles had significant differences during the stroke phase (p < 0.05). The moment of the racket-side hip rotation and ankle dorsiflexion showed significant differences during the stroke phase (p < 0.05). The racket velocity, angle, and trajectories showed significant differences at characteristic moments (p < 0.05). This study revealed the different topspin forehand stroke techniques in table tennis, even though the two movements look similar. Compared with AT strokes, the athletes kept a straight elbow and lower center of gravity than they did during the stroke phase of AB strokes. They increased the distance of the racket trajectory and velocity to meet the incoming ball with a backspin, especially in the vertical direction. This detailed information is necessary for beginners to improve the efficiency of their forehand topspin technique, especially in strokes against incoming balls with different rotations. [ABSTRACT FROM AUTHOR]

The aim of this explorative study was to determine the key inertial measurement unit-based wheelchair mobility performance components during a wheelchair tennis match. A total of 64 wheelchair tennis matches were played by 15 wheelchair tennis players (6 women, 5 men, 4 juniors). All individual tennis wheelchairs were instrumented with inertial measurement units, two on the axes of the wheels and one on the frame. A total of 48 potentially relevant wheelchair tennis outcome variables were initially extracted from the sensor signals, based on previous wheelchair sports research and the input of wheelchair tennis experts (coaches, embedded scientists). A principal component analysis was used to reduce this set of variables to the most relevant outcomes for wheelchair tennis mobility. Results showed that wheelchair mobility performance in wheelchair tennis can be described by six components: rotations to racket side in (1) curves and (2) turns; (3) linear accelerations; (4) rotations to non-racket side in (4) turns and (5) curves; and finally, (6) linear velocities. One or two outcome variables per component were selected to allow an easier interpretation of results. These key outcome variables can be used to adequately describe the wheelchair mobility performance aspect of wheelchair tennis during a wheelchair tennis match and can be monitored during training. [ABSTRACT FROM AUTHOR]

Mixed‐strategy Nash equilibrium is the cornerstone of our understanding of strategic situations that require decision makers to be unpredictable. Using data from nearly half a million serves over 3000 tennis matches, and data on player rankings from the ATP and WTA, we examine whether the behavior of professional tennis players is consistent with equilibrium. We find that win rates conform remarkably closely to the theory for men, but conform somewhat less neatly for women. We show that the behavior in the field of more highly ranked (i.e., better) players conforms more closely to theory. We show that the statistical tests used in the prior related literature are not valid for large samples like ours; we develop a novel statistical test that is valid and show, via Monte Carlo simulations, that it is more powerful against the alternative that receivers follows a nonequilibrium mixture. [ABSTRACT FROM AUTHOR]

Anticipation skill is important for elite racquet sports players. Successful anticipation allows them to predict the actions of the opponent better and take early actions in matches. Existing studies of anticipation behaviors, largely based on the analysis of in‐lab behaviors, failed to capture the characteristics of in‐situ anticipation behaviors in real matches. This research proposes a data‐driven approach for research on anticipation behaviors to gain more accurate and reliable insight into anticipation skills. Collaborating with domain experts in table tennis, we develop a complete solution that includes data collection, the development of a model to evaluate anticipation behaviors, and the design of a visual analytics system called Tac‐Anticipator. Our case study reveals the strengths and weaknesses of top table tennis players' anticipation behaviors. In a word, our work enriches the research methods and guidelines for visual analytics of anticipation behaviors. [ABSTRACT FROM AUTHOR]

The use of statistical tools for predicting the winner in tennis matches has enjoyed an increase in popularity over the last two decades and, currently, a variety of methods are available. In particular, paired comparison approaches make use of latent ability estimates or rating calculations to determine the probability that a player will win a match. In this paper, we extend this latter class of models by using network indicators for the predictions. We propose a measure based on eigenvector centrality. Unlike what happens for the standard paired comparisons class (where the rates or latent abilities only change at time t for those players involved in the matches at time t), the use of a centrality measure allows the ratings of the whole set of players to vary every time there is a new match. The resulting ratings are then used as a covariate in a simple logit model. Evaluating the proposed approach with respect to some popular competing specifications, we find that the centrality-based approach largely and consistently outperforms all the alternative models considered in terms of the prediction accuracy. Finally, the proposed method also achieves positive betting results. [ABSTRACT FROM AUTHOR]

The 1973 Battle of the Sexes tennis match between Billie Jean King and Bobby Riggs provides an example of what I call "sport spectacle." I define "sport spectacle" as a staged encounter in which the institutions of sports and media conjoin with the activities of individual athletes and the gaze of interested audiences to co-produce narratives in which athletic endeavors reflect, shape, or intervene upon social will in material and symbolic ways. Sport spectacle involves a contested co-production of meaning about a sporting event's social importance that occurs before, during, and—through the rhetorical processes of public memory—after the sporting event. I analyze how King and Riggs understood the match within women's movement discourse and the cultural evolution of tennis, in addition to how King and others have treated the match as a cultural touchstone that can be redeployed in public memory. Recent films When Billie Beat Bobby (2001) and The Battle of the Sexes (2017) offer very different characterizations of King's role as a social movement actor and the Battle of the Sexes as a social movement act. While When Billie Beat Bobby credits King with wide-ranging transformation of women's lives in a universe largely devoid of political context, The Battle of the Sexes anachronistically champions [End Page 97] King as a closeted LGBTQ+ icon with a more nuanced understanding of sport spectacle as a transformational gathering that prepares spectators for political contestation. This case study contributes to a growing body of scholarship that attends to the nuanced rhetorical dimensions and political contexts of spectacle. [ABSTRACT FROM AUTHOR]

Introduction: With the widespread use of wearable sensors, various methods to evaluate external physical loads using acceleration signals measured by inertial sensors in sporting activities have been proposed. Acceleration-derived external physical loads have been evaluated as a simple indicator, such as the mean or cumulative values of the target interval. However, such a conventional simplified indicator may not adequately represent the features of the external physical load in sporting activities involving various movement intensities. Therefore, we propose a method to evaluate the external physical load of tennis player based on the histogram of acceleration-derived signal obtained from wearable inertial sensors. Methods: Twenty-eight matches of 14 male collegiate players and 55 matches of 55 male middle-aged players wore sportswear-type wearable sensors during official tennis matches. The norm of the three-dimensional acceleration signal measured using the wearable sensor was smoothed, and the rest period (less than 0.3 G of at least 5 s) was excluded. Because the histogram of the processed acceleration signal showed a bimodal distribution, for example, high- and lowintensity peaks, a Gaussian mixture model was fitted to the histogram, and the model parameters were obtained to characterize the bimodal distribution of the acceleration signal for each player. Results: Among the obtained Gaussian mixture model parameters, the linear discrimination analysis revealed that the mean and standard deviation of the highintensity side acceleration value accurately classified collegiate and middle-aged players with 93% accuracy; however, the conventional method (only the overall mean) showed less accurate classification results (63%). Conclusion: Themean and standard deviation of the high-intensity side extracted by the Gaussian mixture modeling is found to be the effective parameter representing the external physical load of tennis players. The histogram-based feature extraction of the acceleration-derived signal that exhibit multimodal distribution may provide a novel insight into monitoring external physical load in other sporting activities. [ABSTRACT FROM AUTHOR]

We provide a theoretical and empirical analysis of set-level strategic and psychological momentums in a sample of 8,193 ATP best-of-five-set tennis matches where players have asymmetric abilities. Theoretical predictions match observed Set 1 outcomes, the only set with no set-level psychological momentum, but do not match any other sets. We find evidence of psychological reversal: in every set following a non-tie net score, the winner of the previous set underperforms compared to theoretical predictions. [ABSTRACT FROM AUTHOR]

The ATP finals is the concluding tournament of the tennis season since its initiation over 50 years ago. It features the 8 best players of that year and is often considered to be the most prestigious event in the sport other than the 4 grand slams. Unlike any other professional tennis tournament, it includes a round-robin stage where all players in a group compete against each other, making it a unique testbed for examining performance under forgiving conditions, where losing does not immediately result in elimination. Analysis of the distribution of final group standings in the ATP Finals for singles from 1972 to 2021 reveals a surprising pattern, where one of the possible and seemingly likely outcomes almost never materializes. The present study uses a model-free, optimization approach to account for this distinctive phenomenon by calculating what match winning probabilities between players in a group can lead to the observed distribution. Results show that the only way to explain the empirical findings is through a "paradoxical" balance of power where the best player in a group shows a vulnerability against the weakest player. We discuss the possible mechanisms underlying this result and their implications for match prediction, bettors, and tournament organization. [ABSTRACT FROM AUTHOR]

We analyze the chances of winning a tournament under the assumption that the probabilities of winning individual matches follow Bradley-Terry model [2]. We present an exact solution and show a few examples of its use. The examples are from California volleyball tournaments, the round of sixteen in the World Cup and the Champions League, the group stage of the Association of Tennis Professionals tournament, and the volleyball SuperLega in Italy. The computational complexity of the solution grows exponentially fast with the number of teams and we seek approximations via multivariate Gaussian laws. [ABSTRACT FROM AUTHOR]

Simple Summary: The precompetitive anxiety should be controlled in athletes to optimize their performance. In this regard, heart rate variability (HRV) is a non-invasive tool to assess the autonomic nervous system balance. Therefore, this study aims to investigate the HRV response of elite international junior tennis players during an international tournament. Eleven players participate in this study, with a mean age of 15.36 (0.67) years old. The HRV of tennis players are assessed 24 h before the event, and immediately before the first and the second match of the ITF Junior Davis Cup event. Each of the registers lasted 5 min and the time domain, frequency domain, and non-linear variables were extracted. Results show that elite tennis players did not decrease the HRV between the baseline and the first match. However, the HRV response significantly differed between the baseline and the second match. Nevertheless, anxiety was higher before the first match than before the second match. Coaches and physical trainers could use HRV to control and manage the precompetitive anxiety of junior tennis players. The experience in international tournaments and the familiarization with the environment in the second match could explain these results. The aim of the present study was to investigate the evolution of the HRV during an international team tennis tournament in elite junior tennis players. A total of 11 tennis players, with a mean age of 15.36 (0.67) from six nationalities, participated in this cross-sectional study. Participants were measured one day before the event, before the first match, and before the second match of the ITF Junior Davis Cup event. Each of the registers lasted 5 min and the time domain, frequency domain and non-linear variables were extracted. The tournament took place in Valencia (Spain). Results showed that there was not a significant decrease in the heart rate variability (HRV) induced by precompetitive stress. However, significant differences (p-value < 0.05) were found between baseline and second match pre-competition HRV values in low frequency (LFNu) (p-value = 0.008) and high frequency (HFNu) power (p-value = 0.008), LF/HF ratio (p-value = 0.008) and Sample Entropy (SampEn) (p-value = 0.033) variables. Furthermore, cognitive anxiety (measured by CSAI-2r) (p-value = 0.017) and anxiety (measured by STAI-S) (p-value = 0.042) were higher before the first match than before the second match. Coaches and physical trainers could use HRV to control and manage the precompetitive anxiety of junior tennis players. The experience in international tournaments and the familiarization with the environment in the second match could explain these results. [ABSTRACT FROM AUTHOR]

In the four decades straddling the turn of the nineteenth century, the small Ontario town of Niagara-on-the-Lake experienced marked growth in its tourism industry. Catering predominantly to wealthy upper-middle-class Canadian and American visitors, the lake-side settlement offered numerous opportunities for polite recreation. Chief among them was lawn tennis, a sport that sat somewhat outside of the mainstream in terms of its high-class, mixed-sex participation demographic. While its players were imbued with a strong amateur philosophy, local boosters recognized the sport's potential to generate tourism income through its two tournaments, but this hinged on the outward presentation among its players/guests of refined gentility—a reflection of both class and gender—both on and off the court. This article considers how lawn tennis tournaments fit into the town's burgeoning tourism industry, and examines gender relations—particularly the role of women—in relation to this development. [ABSTRACT FROM AUTHOR]

Why is Roger Federer a GOAT (‘Greatest of All Time’) of tennis? I argue that the correct response goes beyond statistics and style of play; instead, it is due to the fact that Federer embodies the qualities that typify sporting genius. More than merely being a developed or refined form of expertise, sporting genius relies on the notion of performative fit; that is, the capacity to express viable ways of succeeding within a given sport in virtue of one’s cultivated history of biological and socio-cultural existence. In other words, a genius such as Federer perfectly fits the requirements of his sport and, moreover, is able to safeguard and shape this fit through his unique disposition to perform in certain ways. Performative fit provides the foundations for received traits of genius such as creativity, self-belief and risk-taking. [ABSTRACT FROM AUTHOR]

With the continuous development of voice coil motors, it has also been widely used in today's sports competitions. For example, the Hawk-Eye system in tennis matches uses voice coil motors to focus on the camera to capture the trajectory of the tennis ball. Therefore, in order to better solve the problem of dynamic parameter uncertainty, external load disturbance, and tracking control of the voice coil motor servo system in motion, this paper proposes for the first time the strategy of using L1 adaptive control algorithm to control the voice coil motor servo system. First, it briefly analyzes the working principle and control method of the voice coil motor, and then constructs the uncertain parameter model according to the mathematical model of the voice coil motor. The closed-loop system of voice coil motor is simulated and analyzed by L1 adaptive controller. The results show that the L1 adaptive control method effectively suppresses the high-frequency interference caused by the voice coil motor in operation, can control the tracking error to gradually converge and so the tracking effect is better, and has strong robustness to the perturbation of system parameters. It can be applied to voice coil motor servo control. [ABSTRACT FROM AUTHOR]

Professional tennis tournaments have onsite sports medicine physicians who oversee the athletes' overall health during competition, including musculoskeletal injury and general illnesses. The medical team is composed of orthopedic and non-operative sports medicine physicians. Frequently, the tournament doctors require imaging to localize and grade musculoskeletal injuries and to make decisions regarding treatment, safe training, and return to match play. The most versatile and readily available imaging modality to evaluate for acute musculoskeletal injury is point-of-care ultrasonography. In 2015, a dedicated radiology service was created at the US Open by bringing in a musculoskeletal radiologist who would perform ultrasounds in a formal and consistent manner. In addition, the radiologist was tasked with onsite radiography as well as review of all MRI examinations done at the imaging center. This article describes how this radiology service was implemented, what types of studies were performed and the advantages of having an onsite musculoskeletal radiologist at the tournament. This service allowed the medical team to provide the comprehensive and efficient medical care required in a major professional tennis event. It also showed the value of having the in-person expertise of the musculoskeletal radiologist in the sports medicine team. This same model could be applied to other professional sporting events. [ABSTRACT FROM AUTHOR]