noun
hard ball; regulation ball
Used in sports such as baseball or tennis to refer to a ball that is hard or meets official standards, often contrasted with 軟球 (soft ball).
Antonyms: 軟球
硬球を使った練習は、軟球よりも打球が速い。
Practice with a hard ball produces faster hits than with a soft ball.
公式戦では硬球が使用
A regulation ball is used in official matches.