curveball

A forespin pitch thrown by rotating the index and middle fingers down and resulting in motion down "curve"

He bit on a curveball in the dirt.

Caglianone ripped Miles Mikolas’ curveball into the right-field corner for an RBI double that scored Salvador Perez in the fourth inning of the first game of a doubleheader against the Cardinals.

An unexpected turn of events initiated by an opponent or chance; an exception or outlier.

Life has thrown him a few curveballs.

The season’s first episode, “Bart Gets an F,” got the highest ratings in its history, but “Treehouse of Horror” was the real curveball: a genre-busting effort that proudly punched above the show’s expectations.

To throw a curveball.

Even though the haughty physics professors at the elite school ridiculed his declaration that he could make a baseball curve, Cummings just laughed it off and said, “I curveballed them to death,” according to Frederick Ivor-Campbell.

The news curveballed him. He'd been hamstrung and schizzed all the preceding weeks. He brooded in his den.