To keep a poker face

Origin

The high-stakes tables of 19th-century American poker rooms gave birth to this iconic phrase. As players stared down their opponents, each vying for the pot with a mix of strategy and sheer nerve, the ability to conceal one's hand and intentions was paramount. A "poker face" was the ultimate weapon—a mask of absolute neutrality, betraying not a flicker of emotion whether holding a winning flush or a hopeless pair of twos. This masterful control over one's expression became synonymous with hiding one's true feelings, an essential skill for bluffs and breakthroughs far beyond the card game.