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The purpose of this study was to compare shifts in the centre of gravity (CG) when balls were tossed at different velocities, in order to obtain data for coaching purposes. The subjects were 10 experienced university baseball players. The subject batted basic toss up ball toward the centre field, both fastballs and slowballs. Data were collected using 2 high-speed cameras (NAC Inc., Japan). The movement timing and velocity of the center of gravity were computed. Batting motion was divided into three phases. The mean times in the 1st phase and 3rd phase were approximately the same for both fast and slow balls, but both the time and distance by which the CG moved in the 2nd phase were significantly greater for slow balls than for fast balls.