Scoring bias caused by services in table tennis: a statistical analysis

In table tennis, servers have the potential advantage of scoring bias when serving. However, the length of the scoring bias, i.e. the shot number where any bias is eliminated, has not been clarified. This study aimed to clarify the level and length of scoring bias occurring at services in table tennis. We analysed 45 men’s singles matches (3,665 rallies) and 29 women’s singles matches (2,352 rallies) from the 2012 London Olympic games and 49 men’s singles matches (4,404 rallies) and 31 women’s singles matches (2,320 rallies) from the 2016 Rio Olympic games. The statistical analysis revealed that services generate a low scoring phase at the second shot and slightly high scoring phase at the third shot. Moreover, the level of the scoring bias became trivial after the third shot, although a small scoring bias could remain. Players should therefore be cautious of a scoring bias until the third shot. In the gender comparison, the scoring bias observed in matches of male players was larger than that of female players up to the third shot. This result indicates that male players are more likely to take advantage of service than female players. In the winner/loser comparison, it was found that losers use the service to create scoring bias as effectively as winners do. Losers’ inferior skills and tactics in the shots after services were the major factor in the difference in the occurrence of missed shots between winners and losers. Finally, we found that the performance of each shot number should be analysed separately up to the third shot, as the remaining effect of the service is remarkably different among shot numbers. The results of this study contribute important suggestions to the conventional methods of performance analysis that empirically separate a rally into three phases

Influence of playing style on the occurrence of missed shots in table tennis

Although the defensive style is competitive in modern table tennis, statistical analyses of it have been limited. The purpose of this study was to clarify the influence of playing style on the occurrence of missed shots, i.e. shots that resulted in a score for the opponent in table tennis. This study found that the defensive style decreases the incidence of missed shots, particularly after the fourth shot, although those of the second and the following shots also decrease. In matches played by a defensive player, missed shots were 6 to 8% less likely to occur than in matches between two offensive players. In addition, the defensive style reduces the likelihood of missed shots in a rally served by an offensive player, and the amount of reduction is about the same as in a rally served by a defensive player. By gender, male defensive players were less defensive than female. We also found it difficult to identify defensive players by the occurrence of missed shots because there might be players not categorised as having defensive style who were as defensive as defensive players

Role of co-contraction of antagonist muscles during predatory strike in the mantis

The 11th International Symposium on Adaptive Motion of Animals and Machines. Kobe University, Japan. 2023-06-06/09. Adaptive Motion of Animals and Machines Organizing Committee.Poster Session P2

Measurement model for attenuation of leaky surface acoustic waves by the line-focus-beam ultrasonic material characterization system

2008 IEEE International Ultrasonics Symposium Proceeding

DEVELOPMENT OF A TABLE TENNIS MACHINE TO COUNTER THE “CHIQUITA” SPIN

After Beijing Olympics, leading athletes began to use a stroke known as the “Chiquita” spin frequently. Thus, the Japan national table tennis team at the time undertook countermeasures against the Chiquita spin including some plans. However, these did not produce significant results. Therefore, we developed a table tennis training machine for the team in activities supporting the Japan national table tennis team. The machine has 3 rotors to shoot a ball stably. Also, these rotors are twisted to make a “gyro rotation” of the ball. This machine was introduced into the Japan national table tennis team to take measures for London 2012 Olympic

Indistinguibilidad de la cinemática de la raqueta y del cuerpo en diferentes servicios de tenis de mesa en jugadores internaciones de élite e intermedios

Table tennis serves are strokes in which disguise and deception skills are important. This study aimed to investigate whether international elite table tennis players can make their racket and body kinematics more indistinguishable than intermediate players during three different serve types. Five former international elite and 8 intermediate players performed 3–12 trials of each serve type. The kinematics of the server’s body and the racket was determined using a motion capture system. The time instant of racket-ball impact was determined using a high-speed video camera with the motion capture system. Misclassification rates when the serve type was classified using the racket and body kinematics were determined using linear discriminant analysis. Elite players showed higher misclassification rates for the racket kinematics than intermediate players during the early swing and follow-through phases. The body kinematics suggested that the elite players made their racket kinematics more indistinguishable using different approaches between the early swing and follow-through phases. The elite players tended to make the racket’s angular velocity more similar and make the wrist rotational variables more indistinguishable in different serves compared to the intermediate players during the early swing phase. In contrast, the elite players made the racket’s linear motion more variable within individual serve types than the intermediate players during the follow-through. The results suggest that intermediate players are recommended to practice making wrist angular motions more similar during the early swing phase and making racket linear motions more variable during the follow-through in order to improve the disguise skill in table tennis serves.Los servicios en el tenis de mesa son movimientos en los que las habilidades para enmascarar y engañar son importantes. El objetivo de este estudio fue investigar si los jugadores de tenis de mesa de élite internacionales pueden hacer que la cinemática de su raqueta y cuerpo sea más indistinguible que los jugadores intermedios durante tres tipos de servicio diferentes. Cinco exjugadores internacionales de élite y 8 jugadores intermedios realizaron de 3 a 12 intentos de cada tipo de servicio. La cinemática del cuerpo y de la raqueta del servidor fue determinada a través de un sistema de captura del movimiento. El momento del impacto raqueta-pelota fue determinado usando una videocámara de alta velocidad con sistema de captura de movimiento. Las tasas de clasificación errónea cuando el tipo de servicio fue clasificado usando la cinemática de la raqueta y del cuerpo fueron determinadas por medio de un análisis discriminante linear. Los jugadores de élite mostraron tasas de clasificación errónea más altas en la cinemática de la raqueta que los jugadores intermedios durante la fase inicial del swing y la fase de terminación. La cinemática del cuerpo sugirió que los jugadores de élite hicieron su cinemática de la raqueta más indistinguible al usar diferentes enfoques entre la fase inicial del swing y la de terminación. Los jugadores de élite tuvieron una tendencia a hacer que la velocidad angular de la raqueta fuera más similar y las variables de rotación de la muñeca fueran más indistinguibles en diferentes servicios comparados con los jugadores intermedios durante la fase inicial del swing. En contraste, los jugadores de élite hicieron que el movimiento lineal de la raqueta fuera más variable en tipos de servicio individual que los jugadores intermedios durante la terminación. Los resultados sugieren que los jugadores intermedios deberían hacer movimientos angulares de muñeca más similares durante la fase inicial del swing y hacer que los movimientos lineares de la raqueta sean más variables durante la terminación para mejorar la habilidad para enmascarar los servicios de tenis de mesa