The poem is the story of a sneer; more specifically, it’s the story of how facial expressions reveal emotional and psychological growth. When Casey advances to the plate, he smiles generously to the crowd who sees in his bulk, in his skill, in his reputation a reason to hope and win the game. Casey loves the adulation. But when he turns to face the “writhing pitcher” (Line 27), that smiles twists into a sneer. And when, two pitches later, Casey faces an entirely new set of circumstances, one that threatens to render ironic the fans’ adulation, that “sneer is gone from Casey’s lip” (Line 45).

The sneer symbolizes the moral lesson that Casey learns too late. A sneer is a curl of the lip that reveals disdain, even contempt. Unlike a smile, which is a generous and inviting facial expression, the sneer, more of a kink in one side of the lips, is intended to create a feeling of imminent threat and infers that the person sneering assumes a position of dominance and empowerment. That the sneer is gone by the last pitch indicates through body language that Casey has already learned a lesson. He realizes he is not in control of the game and must now face what every lesser human being routinely faces every day: the unexpected.