Difference between American baseball and Japanese baseball

Even the same baseball, there are variety of difference between American baseball and Japanese. When a Japanese player goes to Major League, Japanese often hear that the balls are different. Besides that there are other differences in rules and audience supporting. Here, we will introduce the difference between American baseball and Japanese baseball.


  1. Difference of equipment

  2. Difference of rule

  3. Difference of support

  4. Difference related to player

  5. Other differences


Difference of equipment

Difference of ball





About 141.7g

About 22.9cm

Major League

About 148.8g

About 23.5cm

In Japanese professional baseball and major league, the size and weight of the ball are different like this. Weighing from 141.7 grams to 148.8 grams, circumference ranging from 22.9 centimeters to 23.5 centimeters is determined according to the rules of baseball.

So, Japan is the minimum value within the provisions, major League is the maximum value of the regulation. Also, the ball’s texture is different, Japanese balls are relatively unlikely to slip, and the seams of the balls are made lower. In the Major League, the coefficient of restitution of balls falls apart, but in Japan the coefficient of restitution of ball is constant, so there is no handicap due to the ball difference.

(URL: http://wsc-media.jp/post-1901/)

Difference of bat

In major league, white ash and hard maple are often used as materials of bat. In Japan, Aodamo and Yachidamo are used in addition to the same white ash as the United States. Aodamo etc are soft and easy to hit.

AODAMO bat             

(URL: https://item.rakuten.co.jp/yakyu-kasukawa/2tw120/)

Difference of mound

The Japanese mound is softer compared to the major league’s one. The Japanese mound is soft so the pitchers make a hole that matches their step and they uses it to throw.

(URL: http://blogimg.goo.ne.jp/user_image/63/83/bfb11e954e0d540b8e56d6badef66d15.jpg)

Difference of rule

An extra‐inning game

An extra games of major league basically the number of innings and time is unlimited.

But, in Japanese professional baseball there is a rule that the extension game is up to 12 innings. If the game is not over in 12 innings, it will be a draw.

Strike zone

By the rule, the strike zone is defined as the space above home plate and between the batter’s knees and the midpoint of their torso. Although The rules on this strike zone are common in both Japan and the United States, Both countries differ slightly from this rule. In both countries the strike zone tends to be wider on the outside. And the strike zone of Major League is wider outside than the Japanese one.

Difference of support

Watching style

In the Major League, the stadium will heat up with applause and cheering, but in Japan there are cheering songs for the athletes, and in addition to cheering, fans will support them with trumpets and drums. Also there are some places that can not be done depending on the stadium, but the form to fly a jet balloon before the 7th inning attack is established.

(URL: https://www.nikkansports.com/baseball/column/bankisha/news/201805010000286.html)

Difference related to player

Starting pitcher

In the Major League, the starting pitcher basically throws up to around 100 balls, but in Japan the starting pitcher may sometimes pitch a complete game. In the Major League, the number of games is large, and pitcher’s throwing game Interval is short. But in Japan, basically it is rotated by six people, the reason is that starting pitcher can rest their shoulders slowly.

active rosters

In Japan, up to 28 players can register. Among them, up to 25 people who were nominated before the game can actually participate in the game. Also foreign players participation There are a maximum of 4 players registered, and only 3 people can register as a fielder or pitcher

Other differences

Protest against the referee

In Japan, there are many cases to protest against judgment of the referee. some people consider the protest against the referee a show. Some referees have interesting judgment on strike call.