MEASURING OPEN SPACE QUANTITATIVELY IN ONE-UP-ONE-BACK FORMATION DURING SOFT-TENNIS DOUBLES GAME

Abstract

The purpose of this study was to quantitatively define and measure the area of open space in one-up-one-back formation adopted in soft-tennis doubles game. Using the film images of real games, the variables of forehand ground strokes and ball bounces for 153 shots were analyzed with the direct linear transformation procedure. Further taking types of stroke technique and game situations into considerations, horizontal distance between contact point and landing point of shots were predicted by multiple regression analysis. As the result, four scales (two for stroke characteristics, stroke technique, and game situation) were selected as significant predictors. Then on the basis of these data, we predicted the horizontal distance of shots and defined the potential areas on court as "open space" in which shots could be landed, and actually computed the area of open space on one case in the game.