Ball Specifications
Also known as: softball specs, 12-inch ball, softball size
Standard slow-pitch softball specifications call for a 12-inch circumference ball with a defined COR and compression rating. Men's and co-ed leagues commonly use a 12-inch ball; some senior and mixed leagues use an 11-inch ball.
The ball's COR (bounciness) and compression (hardness) are regulated by the sanctioning association and must match the approved ball list for the event. A 0.44 COR / 375-compression ball is a common recreational standard; more competitive leagues may use 0.52 COR balls. The cover is typically polyurethane or leather stitched over a polyurethane foam and cork center. Because the ball is the largest single performance variable — harder balls fly farther — using the wrong ball even with a certified bat can mean an unfair advantage or disadvantage.
Example
A team brings 0.52 COR balls to a 0.44 COR league; the opposing captain notices and the umpire rules the team must use league-supplied 0.44 balls for the rest of the game.
Related terms
- COR (Coefficient of Restitution)COR measures how "lively" a softball is — the ratio of its rebound speed to its impact speed against a hard surface. A higher COR ball comes off the bat faster.
- Compression RatingCompression rating measures how much force it takes to compress a softball a quarter inch, in pounds per square inch. A higher rating means a harder ball with more pop.
- Glove – Slow-PitchA slow-pitch softball glove is sized for the larger 12-inch ball — typically 12 to 13.5 inches for infielders, up to 14 inches for outfielders — with a deeper, wider pocket than a baseball glove.
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