From Darwin to the Diamond: How Baseball and Billy Beane Arrived at Moneyball

Abstract

We apply an evolutionary framework to explain why new data analytic methods were successfully applied to baseball in the first decade of the 21st century; a phenomenon popularly characterized as Moneyball. We review work showing that managing a baseball team using the performance metric, batting average, became less effective due to competitive pressures. The variability of batting average has declined since 1900. We show how another performance metric, on base percentage, or the value of taking bases on balls (walks), became more valuable given that batting average declined in value as a potential source of competitive advantage. Walks, while always known to contribute to success in baseball, never were pursued as a source of competitive advantage. Consequently, the variability in walks has been relatively constant throughout the history of baseball, consistent with a lack of competition on this dimension. The timing of this shift in managerial attention and strategy from managing hitting performance to managing on base performance is due, in part, to the value of batting average ''running down'' or being "competed away'' as all teams pursued the same strategy. This phenomenon, illustrates in a novel setting how performance strategies evolve over time under conditions of competition.