70 to 120 Balls Per Game
A single NPB game consumes approximately 70 to 120 baseballs, varying significantly by game flow. Pitchers' duels with many strikeouts use fewer balls, while high-scoring games with frequent foul balls consume more. Balls are replaced when hit into the stands, scuffed by contact with dirt, or when pitchers or umpires judge the surface compromised. While not every pitch requires a new ball, frequent exchanges ensure pitchers always grip a ball with consistent surface texture.
Manufacturing - Mizuno's Exclusive Supply
Mizuno exclusively manufactures NPB's official game balls to strict specifications: 141.7 to 148.8 grams in weight, 22.9 to 23.5 centimeters in circumference. The core combines cork and rubber, wrapped in yarn, and covered with cowhide stitched with 108 seams. The 2011 introduction of the 'unified ball' with a lower coefficient of restitution dramatically reduced home runs, and the 2013 revelation that the coefficient had been secretly restored triggered a major scandal. A single ball's specifications can reshape an entire league's statistics.
The Mud Rub - A Pre-Game Ritual
New baseballs are too slick for pitchers to grip effectively. Before each game, every ball undergoes a 'mud rub,' where a thin layer of special rubbing mud is applied to create appropriate friction. In MLB, mud from a specific New Jersey river has been traditionally used; NPB uses domestically sourced mud. The application requires experienced judgment: too much mud makes the ball slippery, too little leaves it glossy. MLB has recently explored industrial surface treatments as alternatives, and NPB may eventually follow.
Where Foul Balls End Up
Foul balls and home run balls that enter the stands belong to the fans who catch them. This is now standard in both NPB and MLB, though NPB historically asked fans to return balls, a practice that persisted into the 1990s. The shift toward letting fans keep balls reflected a broader emphasis on fan experience in the 2000s. Across a full NPB season, an estimated 60,000 to 100,000 balls are consumed in games, with a significant portion ending up as fan souvenirs.
The Second Life of Used Balls
Balls removed from games but still in reasonable condition are recycled for batting practice and bullpen sessions. Severely damaged balls are discarded. Some game-used balls are repurposed for autograph sessions, charity auctions, or fan events. Balls from historic games, such as opening days, Japan Series, or retirement ceremonies, are preserved as archival artifacts. The Baseball Hall of Fame and Museum displays balls from landmark moments. A baseball's life cycle runs from factory to mud rub to game action to practice field or, for the fortunate few, eternal preservation in a fan's collection.
The Surprisingly High Cost of a Consumable
While NPB does not publicly disclose official ball pricing, professional-grade baseballs typically cost 2,000 to 3,000 yen each. At an estimated 2,500 yen per ball and 100 balls per game, each game costs roughly 250,000 yen in baseballs alone. Across approximately 860 games per season, NPB spends an estimated 215 million yen annually on game balls, or about 18 million yen per team. This is modest compared to player salaries, yet each individual ball directly influences outcomes. A 0.1-millimeter difference in seam height alters pitch movement; a 0.01 difference in coefficient of restitution determines whether a fly ball clears the fence. Professional baseball is a sport governed by this small leather sphere.