Japanese-style baseball

Rubber-ball baseball (Japanese: 軟式野球, romanized: nanshiki yakyū), also known as Japanese-style baseball, is a variant of baseball developed in Japan that uses a hollow rubber ball instead of a standard leather baseball. In English, it is also referred to as nankyu baseball, nanshiki baseball, or simply rubber baseball.

Rubber-ball baseball uses a hollow rubber ball that differs significantly from a standard baseball in elasticity and weight, which affects playing style, equipment, and player technique.^[1] Apart from the ball, the rules are largely the same as those of conventional baseball. By contrast, the ball used in softball is typically leather-covered but larger than a standard baseball.

The term may refer specifically to baseball played with a hollow rubber ball, or more broadly to variants in which the outer layer of a standard baseball is replaced with rubber.

It is widely played in Japan by children and adults, including both men and women.

During the Meiji era (1868–1912), baseball introduced from the United States became established in Japan, particularly in secondary schools, high schools, and universities. At the time, children often played using hard tennis balls; however, these proved less suitable due to durability and speed issues, and participation gradually declined.

In 1919, Toshin Rubber, a company based in Kobe, marketed the world’s first rubber baseball. In July of the same year, a rubber-ball baseball tournament was held at Kyoto Municipal Seitoku Elementary School (now Kyoto Culture Association (京都文化協会, Kyōto bunka kyōkai)) in Kyoto, marking one of the earliest organized competitions. A monument in Takaragaike Park Youth Sports Park (宝が池公園少年スポーツ広場, Takaragaike kōen shōnen supōtsu hiroba) commemorates the site as the birthplace of the sport.

The introduction of rubber balls led to renewed interest in youth baseball, and in 1920 the Japan Association of Youth Baseball (大日本少年野球協会, Dai-nippon shōnen yakyū-kyōkai) was established in Kobe, organizing national youth tournaments.

In 1922, balls for general use were introduced. Their inventor, Sakae Suzuka (鈴鹿 栄, Suzuka Sakae), referred to them as "softballs" (nanshiki bōru), and the game played with them as nanshiki yakyū.

In 1925, Haruno Yokoi (横井 春野, Yokoi Haruno) established a youth baseball association in Tokyo.

The ball has undergone several revisions, with current specifications established in December 2016 by the Japan Rubber Baseball Association (公益財団法人全日本軟式野球連盟) and the Baseball Ball Manufacturers Association (野球ボール工業会).

Two types are specified: type M (major) and type J (junior). Type M has a diameter of 71.5–72.5 millimetres (2.81–2.85 in), while type J has a diameter of 68.5–69.5 millimetres (2.70–2.74 in).^[2]

In comparison, a regulation leather baseball is 73–75 millimetres (2.9–3.0 in) in diameter. An 11-inch softball has a diameter of about 89 millimetres (3.5 in).^[3]

• Rubber ball (left) and leather baseball (right)
• A K-ball designed to bridge rubber-ball and hardball baseball

While both metal and wooden bats are used in standard baseball, rubber-ball baseball commonly uses metal or carbon bats designed for use with rubber balls.

Major competitions in Japan include:

General public

• All Japan Baseball Tournament (Men's Tournament)
• Emperor's Cup All-Japan Baseball Tournament
• Takamatsu Miyagi Cup All-Japan Baseball Tournament (Division 1, Division 2)
• All-Japan Women's Nanshiki Championship
• National Sports Festival (Men's Competition)

University students

• All Japan University Baseball Championship (Spring)
• All Japan University Women's Nanshiki Baseball Championship

Vocational school students

• All Japan Vocational School Nanshiki Championship

High school students

• All Japan High School Baseball Championship

In Cuba, a similar game known as cuatro esquinas is played, and related forms of rubber-ball baseball are also played in Taiwan.

Rubber-ball baseball is commonly played at the university level,^[4] and the World University Rubber-ball Baseball Tournament (Japanese: 世界大学軟式野球大会, romanized: Sekai daigaku nanshiki yakyū taikai) is held periodically in Japan and overseas, including in the United States, Guam, and Taiwan.^[5]

The International Boys Nankyu Baseball World Championship (Japanese: 少年軟式野球世界大会, romanized: Shōnen nanshiki yakyū sekai taikai), an annual international tournament for players under 12, is organized by the International Boys Nankyu Baseball Association Japan and held in Tokyo, typically at Edogawa Baseball Stadium.^[6]

• Japan Rubber Baseball Association

• Sports Nippon article
• Tokyo Nanshiki Baseball Association