Because genuinely easy cases and straightforward applications of legal rules are so rarely disputed in court, the array of disputes that do wind up in court represents a skewed sample of legal events. The effect, known as the selection effect," is such that the cases that wind up in court are only-or almost only-the ones in which two opposing parties holding mutually exclusive views about some legal question both believe they have a reasonable chance of winning.

Unknown, Frederick Schauer - Thinkin…, loc. 38