Baseball term referring to the quality of a pitcher's pitches, including speed, movement, and overall effectiveness.
His pitches got noticeably stronger in the latter innings.
He throws a fastball with good stuff.
今日の先発投手は球威が落ちている。
Today's starting pitcher's stuff is not as sharp.
疲れで球威が落ちてきた。
Fatigue caused his pitches to lose their power.
He shut down the opposing lineup with the power of his pitches.
球速 refers only to how fast a pitch travels, while 球威 covers the overall power and movement that make a pitch hard to hit.
制球 means a pitcher's control or command of location, whereas 球威 refers to the raw quality and power of the pitches themselves.
Compound of 球 (ball) and 威 (power, authority). The exact historical derivation is uncertain, but the word is conventionally associated with the power or effectiveness of a pitched ball.