標的サイズと投球コントロールの正確性

Abstract

It has been demonstrated that, when one points a finger at a target placed at a short distance of 40 to 50 cm, the accuracy of pointing increases as the target size decreases. The purpose of our experiment is to prove that the accuracy in ball throwing increases as the target size decreases when throwing a ball at a target placed at a long distance. The subjects who participated in the experiment were all college sports players, consisting of 4 baseball players, 2 handball players, 2 softball players and 2 American football players. Four target sizes were used, which were 10cm in dia. (small), 30cm in dia. (medium), 60cm in dia. (large) and no target. Each subject threw the ball at a different distance set for each respective sport to enable optimum control in ball throwing for the sport. Each subject threw a total of 800 balls, throwing 200 balls at each type of target. Thus a total of 8,000 balls were thrown by all the subjects. The accuracy in ball throwing was evaluated by using the average distance between the target center and the point where the ball hit the board the target was marked on. The results show the following:1. For all subjects who specialized in handball, softball and American football, the highest accuracy in ball throwing was observed with the small target, which was followed by the medium-size target, the large target and no target in descending order. 2. For all subjects who specialized in baseball, the highest accuracy in ball throwing was observed with the medium-size target, which was followed by the small target, the large target and no target in descending order. This result may be explained by the long distance set for the baseball players between the players and target which made the smallest target too small for the subjects to exercise any control when throwing their ball. 3 It has been shown in our experiment that the accuracy in ball throwing increases as the target size decreases.