In baseball, a pitch that moves or breaks (e.g., curve, slider); figuratively, an unexpected or unconventional move/comment.
彼は決勝で変化球を投げて三振を取った。
He threw a breaking ball in the final and struck him out.
会議でいきなり変化球を出されて、皆が驚いた。
They were surprised when someone suddenly threw an unexpected suggestion in the meeting.
プロの投手はカーブやスライダーなど多くの変化球を使い分ける。
Professional pitchers mix many breaking pitches, like curveballs and sliders.