[A knuckleball is] a curve ball that doesn't give a damn.

Cannon’s line captures the knuckleball’s defining trait: unpredictability. A normal curveball “breaks” according to spin and intention; the knuckleball, thrown with minimal rotation, can flutter erratically, seeming to ignore both the pitcher’s plan and the hitter’s expectations. Calling it “a curve ball that doesn’t give a damn” personifies the pitch as willfully indifferent—an outlaw version of a breaking ball that refuses to behave. The quip also reflects mid‑century sportswriting’s taste for tough, comic metaphor, turning a technical phenomenon (aerodynamics and spin) into a memorable character sketch of baseball’s most capricious pitch.