The Sabermetric Revolution: Assessing the Growth of Analytics in Baseball

4. An Overview of Current Sabermetric Thought II: Defense, WAR, and Strategy

4 An Overview of Current Sabermetric Thought II Defense, WAR, and Strategy In this chapter we first turn our attention to how sabermetricians have approached the analysis of defense in baseball and then focus on unresolved issues in sabermetric thought. As we will see, for a variety of reasons, the accurate measurement of player contributions on the defensive side has proven far more elusive to sabermetricians than the corresponding offensive components. Defense Bill James’s model (and common sense) for expected winning percentage makes it clear that preventing the opposing team from scoring is just as important as scoring runs. The repeated refrain that “defense wins championships ” is as prevalent in baseball as it is in other sports, although it is sometimes morphed into phrases like “good pitching beats good hitting.” But the concept of defense in baseball is more similar to that of soccer or hockey than it is to basketball or football. In the former sports, one player (the goalie, or pitcher) is designated almost entirely for defensive purposes, and he plays a tremendous role in determining the number of points that are allowed, while the majority of his teammates are often focused more on offense and play more complementary defensive roles. Conversely, in basketball all players must contribute on both offense and defense, and while some players may 58 Chapter 4 excel in one facet of the game or another, there is no designation that changes what certain players are allowed to do. In football, with the days of the twoway player largely in the past, a change of possession usually brings a complete changeover of personnel for both teams. What is difficult in baseball (or soccer or hockey) is measuring the extent of the defensive contribution of the pitcher (goalie) relative to the other fielders (defensemen). In the same way that we presented separate discussions of baserunning and hitting (which together comprise offense) above, in what follows we present separate discussions of fielding and pitching (which together comprise defense). Pitching The evaluation of pitchers changed remarkably little until the theory of Defense Independent Pitching Statistics (DIPS) was advanced by Vörös McCracken in January 2001.1 Prior to DIPS, starting pitchers were evaluated by their won-loss record, earned run average (ERA), and other proxies for the depth and quality of their contribution (innings pitched, strikeouts, etc.), while relievers were judged by those same metrics, but also saves and holds. Indeed, Bill James and Rob Neyer developed a simple formula to combine these elements into a Cy Young Predictor, which has correctly identified the winner of the Cy Young Award in sixty-seven of ninety cases since the award was first given to a pitcher in each league in 1967.2 Although many had noted how a pitcher’s won-loss record depended heavily on factors that were entirely outside the pitcher’s control (e.g., the offensive performance of his teammates, or the performance of the relievers who followed him in the game), ERA (earned run average) was still considered to be an accurate reflection of the quality of a pitcher’s performance.3 However, DIPS theory has largely discredited even this venerable metric, by demonstrating that the percentage of balls put into play against a particular pitcher that fall for hits is much more subject to chance than conventional wisdom allowed. Although the original incarnation of DIPS theory—that pitchers had zero control over this ratio—has been weakened by several arguments , the general thrust that pitchers have far less control over the batting average on balls put in play against them than was previously believed, Overview of Sabermetric Thought II 59 is widely accepted within the sabermetrics community inside and outside of the industry. This tenet is now fundamental to understanding the relationship between pitching and defense. Indeed, even major league pitchers such as Zack Greinke and Brandon McCarthy are known to be disciples of DIPS.4 This represents a considerable change since Moneyball, at which time “McCracken ’s astonishing discovery about major league pitchers had no apparent effect on the management, or evaluation, of actual pitchers.”5 Given its importance, we explore this notion in some detail below. McCracken ’s original conclusion was: “There is little if any difference among major-league pitchers in their ability to prevent hits on balls hit in the field of play.” What does this mean? Certainly it does not mean, as has been...