Useful Cues for the Tennis Receiver: a Two-Dimensional Analysis of Service Types James J. Tufano1 • Jan Carboch2 • Vladimir Suss2 Department of Physiology and Biochemistry1 • Department of Sport Games2 • Faculty of Physical Education and Sport Charles University, Prague, Czech Republic ABSTRACT PURPOSE: The purpose of this study was to determine whether tennis players toss the ball differently when serving different types of serves to different locations. METHODS: Professional male right-handed tennis players from central Europe (n=15) with a mean ranking of 648 on the ATP participated in the study. After performing their regular pre-match warm-up, participants hit three successful serves to the following locations: flat serves wide (FW), flat serves to the T (FT), second serves wide (2W), second serves to the T (2T), slice serves wide (SW), and kick serves to the T (KT). After completing all serves from the deuce court, players rested for 3 min before serving from the ad court, following the same procedure as from the deuce court, but the kick serve wide (KW) preceded the slice serve to the T (ST). To determine 2-dimensional ball toss kinematics from the receiver’s point of view, participants were recorded using a high-speed camera (400 Hz) placed at the opposite (receiving) end of the indoor tennis court. The origin of the 2-dimensional global coordinate system was translated to the position of the toes of the front service foot. The point of ball release, vertical toss peak, and racket-ball contact point were analyzed. RESULTS: Results showed that the vertical toss peak and racket-ball contact point of the kick serve occurred further to the right compared to other serve types (Figure 1). From the deuce court, the KT had a vertical toss peak about 18-20 cm further to the right from the receiver’s point of view compared to the FW, FT, and SW (p < 0.001). Also, the racket-ball contact point of the KT was 30-35 cm further to the right compared to the FW, FT, and SW (p < 0.001). Like the KT from the deuce court, the vertical toss peak and racket-ball contact points of the KW from the ad court were about 19 (p < 0.001) and 30-33 cm (p < 0.001) further to the right of the server compared to FW, FT, and ST. The toss trajectory of the 2T and 2W differed, but only from the deuce court. The vertical toss peak of 2W was about 11 cm further to the left (p < 0.001), whilst the racket-ball contact point was about 18 cm to the left compared to 2T (p < 0.001). CONCLUSIONS: Although the point of ball release was similar between different types of serves, the kick serve demonstrated a distinct and rightward vertical toss peak and racket-ball contact point along the x-axis. These findings indicate that a receiving player may be able to anticipate the kick serve and the direction of the second serve from the deuce court. PRACTICAL APPLICATIONS: Coaches and players should be aware that when receiving, a more horizontal ball toss may indicate the use of a kick serve or a second serve wide. When serving, players should attempt to utilize the same ball toss regardless of serve type and location. ACKNOWLEDGEMENTS: Financial support was provided by Charles University Progress, No. Q41: Biological aspects of the investigation of human movement. PURPOSE The purpose of this study was to determine whether tennis players toss the ball differently when serving different types of serves to different locations. RESULTS Results showed that the vertical toss peak and racket-ball contact point of the kick serve occurred further to the right compared to other serve types (Figure 1). From the deuce court, the KT had a vertical toss peak about 18-20 cm further to the right from the receiver’s point of view compared to the FW, FT, and SW (p < 0.001). Also, the racket-ball contact point of the KT was 30-35 cm further to the right compared to the FW, FT, and SW (p < 0.001). Like the KT from the deuce court, the vertical toss peak and racket-ball contact points of the KW from the ad court were about 19 (p < 0.001) and 30-33 cm (p < 0.001) further to the right of the server compared to FW, FT, and ST. The toss trajectory of the 2T and 2W differed, but only from the deuce court (Figure 2). The vertical toss peak of 2W was about 11 cm further to the left (p < 0.001), whilst the racket-ball contact point was about 18 cm to the left compared to 2T (p < 0.001). METHODS Professional male right-handed tennis players from central Europe (n=15) with a mean ranking of 648 on the ATP participated in the study. After performing their regular pre-match warm-up, participants hit three successful serves to the following locations: flat serves wide (FW), flat serves to the T (FT), second serves wide (2W), second serves to the T (2T), slice serves wide (SW), and kick serves to the T (KT). After completing all serves from the deuce court, players rested for 3 min before serving from the ad court, following the same procedure as from the deuce court, but the kick serve wide (KW) preceded the slice serve to the T (ST). To determine 2-dimensional ball toss kinematics from the receiver’s point of view, participants were recorded using a high-speed camera (400 Hz) placed at the opposite (receiving) end of the indoor tennis court. The origin of the 2-dimensional global coordinate system was translated to the position of the toes of the front service foot. The point of ball release, vertical toss peak, and racket-ball contact point were analyzed. Deuce-Court Ad-Court Figure 1. First serve types and locations. Data points show the point of ball release (bottom left), vertical toss peak (apex), and racket-ball contact point (bottom right). CONCLUSIONS Although the point of ball release was similar between different types of serves, the kick serve demonstrated a distinct and rightward vertical toss peak and racket-ball contact point along the x-axis. These findings indicate that a receiving player may be able to anticipate the kick serve from both side of the court and the direction of the second serve from the deuce court. PRACTICAL APPLICATIONS Coaches and players should be aware that when receiving, a more rightward ball toss may indicate the use of a kick serve or a second serve wide. When serving, players should attempt to utilize the same ball toss regardless of serve type and location. Deuce-Court Ad-Court Figure 2. Second serve locations. Data points show the point of ball release (bottom left), vertical toss peak (apex), and racket-ball contact point (bottom right). CONTACT Jan Carboch, Ph.D. carby@post.cz James J. Tufano, Ph.D. james.j.tufano@gmail.com Financial support was provided by Charles University Progress, No. Q41: Biological aspects of the investigation of human movement. ACKNOWLEDGEMENTS © 2017 Faculty of Physical Education and Sport, José Martího 269/31, Prague 6 – Veleslavín, 16252 , Czech Republic