10-inch Ball

• The 10-inch softball is used for boys youth play. It is the softest ball and easier to grasp for youth players. It can be white or yellow optic, and has a core typically made of cork. The stitching can be red or white. There are no ASA-mandated COR and compression guidelines.
  
  

11-inch Ball

• The 11-inch softball approved by ASA is for use in co-ed slow-pitch softball. The ball is yellow optic with red stitching. The COR is a maximum of .440 and the compression is a maximum of 375 pounds.
  
  

12-inch ball

• The 12-inch softball is the most commonly used size in ASA play, since it is approved for various types of competition. The COR and compression vary by the type of play. For fast-pitch play, the ball can be white with white stitches or yellow optic with red stitches, with a maximum COR of .470 and maximum compression of 375 pounds. For modified pitch, the ball can be white with red stitches or yellow optic with red stitches, with a maximum COR of .470 and maximum compression of 375 pounds. For slow pitch, two 12-inch balls are ASA-approved: yellow optic with red stitches, with maximum COR of .440 and maximum compression of 375 pounds; and yellow optic with red stitches, with maximum COR of .520 and maximum compression of 300 pounds.
  
  

16-inch ball

• The 16-inch ball is commonly used in slow-pitch play where field space is limited, and in wheelchair softball. The ball is white with white stitching. The COR is a maximum of .470 and the compression is a maximum of 375 pounds.