The purpose of this study was to characterize the bat swing parameters that increase the flight distance. Thirteen members of a collegiate baseball team performed free-batting practice. The batting performances were recorded with a ultra-high-speed camera and a tri-axial gyro-sensor attached to the grip end of a wooden baseball bat. Flight distance had a high correlation with the kinetic energy possessed by the batted ball (p<0.01) which, in turn, was correlated with the rolling velocity of the bat (p<0.05), the direction of the bat swing (p<0.01) immediately before the impact (p<0.05) and the orientation of the line of impact (p<0.05).