Dozens of books have been published recently on the errors and biases that affect our judgments and choices. Drawing on cognitive science, their lessons are excellent for many kinds of decisions - consumer choice and financial investments, for example - but stop short of addressing many of the most important decisions we face in management, where we can actively influence outcomes and where competitive forces mean we have to outperform rivals. As Phil Rosenzweig shows, drawing on examples from business, sports and politics, this sort of decision-making relies on mastering two very different...