sides of the gamble. Although professional gamblers may be able to directly discuss the spread victor probability, most knowledgeable NFL fans are more prepared to discuss the game victor probability — directly applying their knowledge of teams’ relative strengths and weaknesses to consider which team is likely to win the game. We therefore expect that the game victor probability will be used as a heuristic substitute for the spread victor probability. Discussion of this issue need not involve explicit mention of probability assessments, quantitative or qualitative, only that arguments have clear implications regarding the team whose chances they support. An empirical basis for expecting the above issue substitution in our experiment is provided by the origin of the strong bias toward selecting favorites in NFL spread betting, even though individuals are aware that the spread evens the odds on average, as observed by Simmons and Nelson (2006). They explain this bias via the operation of an intuitive confidence heuristic in which the initial assessment of a spread bet is guided by an individual’s subjective probability concerning who will win the game not beat the spread. Issue substitution then represents the transition of this heuristic from fast System 1 thinking into the focus of discussion in deliberative System 2 thinking (Kahneman and Frederick 2002). The game and spread victor questions can be regarded as two distinct gambles that rely on the same underlying random variable, the margin of victory, but with different thresholds for resolving the outcome: zero and the spread respectively. As a result, their subjective probabilities yield different reference wagers as seen in Figure 2. A spread victor probability of 1 / 2 corresponds to a zero wager rhetorical reference whereas a game victor probability of 1 / 2 yields a negative wager as the rhetorical reference (since 1 / 2 represents the belief that, counter to the oddsmakers, there is no favorite and so the spread is too high, implying an underdog bet). Thus, discussion of the game victor question results in using an improper rhetorical issue. 15