The effect of rule modification on play in tennis:

Induction of offensive shot by using one-trap rule

Abstract

    This study investigated whether the rule modification (i.e., manipulating the number of touches of strokes) in tennis matches induced the shot to be offensive for effective coaching. Sixteen male tennis players with tennis experience over 3 years participated in this study. Each paired participants played tennis singles matches in normal- and modified-rule conditions. One-trap rule was adopted as the modified-rule (permitting two touches of strokes to return the ball). The performance during the match was evaluated by the winner (the shot which the opponent couldnʼt touch) rate and player/ball positions. Assuming that time allowance made by one-trap rule advances the hitting position, the distribution of the hitting position was calculated. In addition, the shortest distance from flying direction to position of the opponent when hitting (abbreviated to D-shortest after this) was calculated, because the advance of the hitting position can make players hit a ball to far place from the opponent.
    Results showed that the winner rate in the one-trap condition was significantly higher than that in the normal condition. The average of the hitting position was approximately 12m behind from the net in anterior-posterior direction in normal condition and approximately 7m behind in one-trap condition. In a rally, D-shortest in the one-trap condition was significantly longer than that in the normal condition. These results suggested that the appropriate rule modification may induce offensive shot.