This study clarifies the features of throwing motion to second base of professional baseball catchers.Eleven catchers of two Nippon Professional Baseball Organization teams were participants. Using the highest confidence data among analytical trials for throwing time, we defined it as 'the time required from catching until ball arriving at second base with shortest time'. Following five characteristic features were revealed. 1) In time parameter, professional catchers have a difference in

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... time (the time required from catching to release in amateur catchers), especially during the beginning phase having a relation with duration time (arrival time from the ball release to the second base), the throwing phase having a relation with the throwing time and release speed (speed average of ball speed of 3 frames after releasing the ball), and the grip changing phase having a relation with motion time. 2) Further, professional catchers have a tradeoff relationship between the motion time and the duration time as well as amateur catchers; and, particularly good professional catchers can shorten the duration time even while shortening motion time leading to shortening of the throwing time. 3) In stride parameter, professional catchers have a difference in the length of the pivot foot in amateur catchers, especially, the X component has a relation with the motion time while the Y component has a relation with the duration time, and the stride length is likewise; there was no relationship between all the items. 4) In release parameter, professional catchers maintain a higher projection height of the ball than amateur catchers and maintain the tendency of the projection angle to be lower, improving the throwing accuracy, especially the elevation angle is related to the duration time and the release speed, but the azimuth angle is likewise; there was no relationship between all the items. 5) In center of gravity of the body, professional catchers have a relation with the movement speed of the center of gravity of the body and the release speed as well as amateur catchers, but the moving distance of center of gravity of the body is likewise; there was no relationship between all the items.