2022 年 22 巻 1 号 p. 25-31
Recently, there has been much debate in the baseball community about limiting the number of pitches thrown by each pitcher in Niigata Prefecture, Japan. Based on this concept, a rule was adapter prior to the 2020 season that each pitcher must have thrown less than 100 pitches. We hypothesized that the pitches per each pitcher would decrease, and the number of pitchers thrown in a game would increase in 2020 season compared in 2019 season. In the present study, we investigated the number of games played by each pitcher, the number of pitches thrown by each pitcher in a game, and the type of games in 2019 and 2020 season to compare the burden on the pitcher before and after the rule was applied. There was no significant difference in the number of pitches per each pitcher in a game between both seasons. In addition, according to the data in complete games, the average number of pitches thrown per pitcher did not exceed 100 pitches in both official and practice games in both seasons, while the average number of pitches were over 100 pitches in both season in games except the complete games in which there was no significant difference. In conclusion, the number of pitches by each pitcher did not decrease sufficiently to be affected by the rule change. In the future, the relationship between number of pitches and disability will need to be clarified, and number of pitches will need to be discussed further.
