Like Major League Baseball in North America, Japanese professional baseball, officially known as Nippon Professional Baseball, holds a championship series, the Japan Series, in October. Japanese professional baseball has two leagues: the Central League and the Pacific League, and each league has six teams. The Pacific League starts its regular season in March, while the Central League begins in April. Both leagues decide their champions by September. For the Japan series, the champion of each league competes against each other, playing in a best of seven game series. The precursor of the current professional baseball began its activities in 1934. Just before the Japanese began professional baseball games, an American professional team, which included Babe Ruth, visited Japan and played a few games with a Japanese team. It is said those US-Japan baseball games promoted the establishment of Japanese professional baseball.