Perhaps the most striking aspect of gambling behavior is that people continue to gamble despite persistent failure. One reason for this persistence may be that gamblers evaluate outcomes in a biased manner. Specifically, gamblers may tend to accept wins at face value but explain away or discount losses. Experiment 1 tested this hypothesis by recording subjects' explanations of the outcomes of their bets on professional football games. The results supported the hypothesis: Subjects spent more time explaining their losses than their wins. A content analysis of these explanations revealed that subjects tended to discount their losses but "bolster" their wins Finally, subjects remembered their losses better during a recall test 3 weeks later. Experiments 2 and 3 extended this analysis by demonstrating that a manipulation of the salience or existence of a critical "fluke" play in a sporting event had a greater impact on the subsequent expectations of those who had bet on the losing team than of those who had bet on the winning team. Both the implications and the possible mechanisms underlying these biases are discussed.