What is the difference between MLB ball and Japanese ball?

  • Compare the different types of baseballs used in Japan’s NPB and America’s MLB leagues
  • Understand how Mizuno baseballs are made vs Rawlings baseballs why Mizuno balls are “stickier”
  • If you want to know about the differences in league rules and such, you should read How is Japanese baseball Different from American baseball post


For the 2020 Tokyo Olympics, the Japanese Olympic Baseball Commission selected SSK to provide baseballs (Mizuno provides all game balls to NPB).

During that time, several MLB pitchers raved about the baseballs, including Joe Ryan who said:

“They need this ball over America. It is amazing. It’s perfect. And the hitters love it. I love throwing with it. All the pitchers love throwing with it. SSK did an outstanding job creating this. So we need this ball. I think it would solve a lot of the current issues that with foreign substances that people like to talk about. It is, I can’t say enough, the best baseball I’ve ever touched.”

SSK Baseballs Used in the 2020 Tokyo Olympics

If you read my post titled Different Types of Baseballs for Different Ages, you know that MLB uses a standardized ball made by Rawlings. There are many complaints about the balls, including size inconsistency, flat seams, and slick surface (the reason why a special mud needs to be rubbed on to every single game balls). And MLB pitchers continue to try and find ways to get that extra grip to induce faster spin on a ball.

Nippon Professional Baseball (NPB) – Unified Game Ball

For the longest time, NPB did not have a standard ball which unfortunately allowed some home teams to doctor up their baseballs to gain an advantage. Since then, Mizuno has been hired to provide all games balls.

In order to perform rudimentary measurements, I had to settle with SSK “Grant Meister” high-school baseballs from Japan because I could not find those SSK game balls from the 2020 Olympics in bulk.

99baseballs Different Types of baseballs used in NPB vs MLB
Mizuno Nippon Professional Baseball
SSK Grand Meister High School Baseball

I also purchased few boxes of Mizuno NPB game balls to see if there were noticeable differences (Yu Darvish gifted Mizuno baseballs to his MLB friends and they were well received).

Unwrapping the Mizuno NPB baseball

Mizuno baseballs for the Nippon Professional Baseball league come individually wrapped in poly bags. Known as the “team unified game ball”, each individual balls come with a hologram sticker with a unique serial number.

Mizuno Team unified Game ball for NPB

Similar to Rawlings’s ROMLB baseballs, there is nothing special about the wrappings, other than a very detailed sticker. However, I was surprised to find that NPB baseballs were made in China instead of Japan.

Unwrapping the SSK “Grand Meister” baseball

Based in Kyoto, Japan, SSK Baseball produces a large number of baseball equipment, including bats, gloves, and of course baseballs.

As noted earlier, the “Grand Meister” model is used at the high-school or college level.

Unlike the wrapper for Rawlings and Mizuno baseballs, SSK balls come double-wrapped, with foil-like exterior layer followed by a shrink-wrapped inner layer.

SSK “Grand Meister” Baseball with Wraps

I presume this was done to prevent moisture penetration as majority of SSK baseballs are made in Sri Lanka which has high humidity

Comparing Baseball Sizes

On a glance, it is really difficult to see the size differences between NPB Mizuno baseballs and MLB Rawlings baseballs.

But once you hold the Mizuno baseball in your hand, you can feel the smaller size right away.

Nippon Professional Baseball vs Major League Baseball

The official circumference on an MLB game ball should be between 9.00 to 9.25 inches. When I measured two random boxes of Rawlings ROMLB baseballs, they averaged around 9.15 inches in circumference.

Using the same measuring method, Mizuno baseballs used in the Nippon Professional Baseball league measured 8.875 inches (or 8 7/8″) in circumference.

SSK “Grand Meister” baseballs used at the high-school and college levels measured at 9 and 9.0625 (9 1/16″) in circumference.

SSK Grand Meister High School Baseball vs MLB Baseball

What was surprising was that unlike Rawlings baseballs, almost all Mizuno and SSK baseballs had the same, consistent circumference and weight measurements.

The smaller Mizuno baseballs for NPB probably has to with the fact that the majority of Japanese players are shorter in height and thus tend to have smaller hands.

Yarn Windings

  • The yarn windings in Japanese baseballs are tightly wound compared to the American baseball
  • Tight winding leads to less offensive games with fewer home runs. This, in turn, emphasizes pitching and strategy, giving the game its unique identity.

Leather Cover

  • coming soon


  • coming soon


  • coming soon


Japanese baseball, while bearing its roots in America, developed with a distinct flavor that is uniquely Japanese.

From its structured youth and school system to the professional NPB league, baseball is ingrained into Japan’s cultural identity.

Baseball is not just a game, but a representation of Japanese values of respect, discipline, and teamwork. Whether you’re a die-hard baseball enthusiast or a casual observer, there’s something captivating about the world of Japanese baseball that’ll make you want to stand up and cheer “Play ball!”.

You May Also Like

Japan’s Craze Over Baseball

Leave a Comment