Many managers complain that they are overwhelmed by how many things they are asked to keep track of in all-inclusive lists of performance measures. It is not uncommon for companies to create scorecards with 30, 40 or more variables, in the mistaken belief that adding measures results in a more complete and therefore better scorecard. Information technology enables us to gather more and more data at lower and lower cost but we cannot keep tracking so many variables. Effective managers monitor only a small number, those that could cause their strategy to fail.