The purpose of this study was to clarify movement tasks of locomotion in ball games and to model them for optimizing training. Coaching manuals and videotapes of games of 13 kinds of sports, including ball games and non-ball games, were utilized as the basic materialsin this study.

    Movement tasks of locomotion in common situation to the sport games, where players didn't operate the ball nor contact with the other players, could be described from the viewpoints of target positions and anticipation of them. Movement tasks for training were then modeled with parameters which were variety of target positions, mobility of them, possibility of anticipation, distance for a target position and time limit to reach it. First three of the parameters indicated the degree of anticipated uncertainties corresponding to the relative relationship between open-skill and closed-skill. It was suggested that operating the parameters in the model could possibly optimize training for locomotion in ball games.