This paper clarifies the historical changes in the Nippon Professional Baseball League (NPBL)(The abbreviation of the current organization is NPB) in two points: The governance system and basic rules about income such as admission fee and broadcasting rights fee. The analysis period was 1936–1952.

When NPBL was founded in 1936, it started with a decentralized governance system and business scheme modeled after the Tokyo University Baseball League. NPBL, as a promoter of the games, distributed profits to baseball teams. The NPBL’s rules regarding income were co-prosperity. After a few years, the governance system became centralized. However, after a temporary suspension due to the war, it returned to its original decentralized system. In 1948, executives of NPBL’s headquarters who aimed to manage a centralized system organized two corporations, a public-interest corporation and a joint-stock company, to reduce the initiative of the teams. However, the corporations did not work well. In this situation, a newspaper publishing company aiming to enter the professional baseball market with the sales strategy of its main business organized a new league. It was the starting point for the current basic rules with a decentralized governance system and free-competitive business scheme, in which the home team as a promoter monopolizes admission fees and broadcasting rights fees.

Previous studies have pointed out that the following causes formed such NPB characteristics:

1) Notification of the corporate tax on advertising expenditure in 1954

2) Inequalities in the number of fans and income from broadcasting rights due to the spread of television

As a correction to this view, this study reveals the following causes:

1) The rejection of NPBL business scheme by the Pacific League in 1950

2) Agreement on broadcasting rights in 1952