Recently, mainly regarding the decrease in the number of spectators, there have arisen rather serious concerns about the commercial popularity of KBO(Korea Baseball Organization) League. However, it must be clear that KBO League, like the U.S. MLB, has the potential to have a significant positive effect on the Korean domestic economy. Therefore, in this study, attention was paid to the possibility that the overall commercial popularity of the KBO League will be promoted if the postseason of the KBO League gets more popular among Korean people. Specifically, based on a game-theoretic approach, a certain way to increase the popularity of the postseason has been investigated. As a result of the analysis, it has been found that obtaining the consent of all teams in the KBO League in order to change the procedure of operating the KBO postseason is not easy in that the existing procedure is highly advantageous for the top team in the regular season. This implies that it should be necessary to reduce the opportunity cost of the top team in the regular season as much as possible if the postseason operating procedure is to be changed to promote the overall commercial popularity of the KBO League.