Why do we know the perfect moment to bid at an auction, hire a candidate, or even pop the champagne? In this episode of Deep Dive, we unpack the theory of optimal stopping—a branch of decision science that pinpoints exactly when to act for the best payoff. From the classic “secretary problem” to real-world applications in finance, dating apps, and bargain hunting, discover how mathematicians model risk, reward, and timing. You’ll learn why sometimes the best choice is to walk away—and how this counterintuitive logic can help you make smarter decisions in everyday life.