The purpose of this study is to examine the effect of Korean professional baseball players' defensive contribution on position and team performance. In other words, the purpose of this study is to present timely implications for the professional baseball teams and the league by measuring the player's effectiveness considering the defensive contribution of baseball players and examining the relationship between each position and the team performance. To this end, we derived defensive efficiency considering efficiency and defensive contribution from 109 players who played 144 at-bats in the 2019 season. According to the analysis results, (1) the efficiency and defensive efficiency of first base, which is the traditional slugger position, both were low, and the catcher and shortstop had the highest defensive efficiency considering the contribution of defense. (2) The correlation between defensive efficiency and team performance was confirmed, and the top 5 teams with high defensive efficiency ranked in the top 5. As a result of this study, it is necessary for professional baseball teams to secure excellent players that are helpful for team performance by using various efficiency indicators suitable for their position in terms of game operation and player management. In addition, it is necessary to evaluate the value of players through efficiency indicators suitable for the characteristics of the position, suggesting that in order to establish a stable profit structure of the club and to advance the Korean professional baseball league. It is necessary to develop and collect and utilize not only offensive data but also defensive data items.