Full explanation — Variance
Variance refers to the statistical ups and downs experienced in poker outcomes. Even a fundamentally profitable player will encounter periods of significant losses over thousands of hands due to random chance. Successfully navigating negative variance is paramount for a professional poker player, making sound bankroll management a critical skill. Understanding variance helps maintain emotional stability, preventing players from questioning their strategy during downswings or becoming overconfident during upswings, which is vital for long-term success.