|1949||Chunichi Dragons, Daiei Stars, Hankyu Braves, Nankai Hawks, Osaka Tigers, Taiyo Robins, Tokyu Flyers, Yomiuri Giants|
|1948||Chunichi Dragons, Hankyu Braves, Kinsei Stars, Kyuei Flyers, Nankai Hawks, Osaka Tigers, Taiyo Robins, Yomiuri Giants|
|1947||Chunichi Dragons, Hankyu Braves, Kinsei Stars, Nankai Hawks, Osaka Tigers, Taiyo Robins, Tokyu Flyers, Yomiuri Giants|
|1946||Chubu Nippon, Gold Star, Hankyu, Kinki Great Ring, Osaka Tigers, Pacific, Senators, Tokyo Kyojin|
|1944||Asahi, Hankyu, Hanshin, Kinki Nippon, Sangyo, Tokyo Kyojin|
|1943||Asahi, Hankyu, Hanshin, Nagoya, Nakai, Nishitetsu, Tokyo Kyojin, Yamato|
|1942||Asahi, Hankyu, Hanshin, Nagoya, Nakai, Taiyo, Tokyo Kyojin, Yamato|
|1941||Asahi, Hankyu, Hanshin, Kurowashi, Nagoya, Nakai, Taiyo, Tokyo Kyojin|
|1940||Hankyu, Hanshin, Kurowashi, Lion, Nagoya, Nagoya Kinko, Nakai, Tokyo Kyojin,
|1939||Eagles, Hankyu, Lion, Nagoya, Nagoya Kinko, Nankai, Osaka Tigers, Tokyo Kyojin,
Historical performance data for professional leagues (affiliated minor leagues, independent minor leagues, fall/winter leagues, and other international leagues) is provided by and licensed from 24-7 Baseball and Chadwick Baseball Bureau. It incorporates the work of many stalwart baseball researchers, including Cliff Blau, Art Cantu, Frank Hamilton, Reed Howard, Kevin Johnson, Bob McConnell, Jack Morris, and Ray Nemec, as well as members of the Minor Leagues Committee of the Society for American Baseball Research.
Perhaps most importantly, it builds upon the seminal work of Ed Washuta, who magnanimously provided the framework to make the whole thing possible.