Predictably Irrational meets Moneyball in ESPN veteran writer and statistical analyst Keith Law’s iconoclastic look at the numbers game of baseball, proving why some of the most trusted stats are surprisingly wrong, explaining what numbers actually work, and exploring what the rise of Big Data means for the future of the sport.

For decades, statistics such as batting average, saves recorded, and pitching won-lost records have been used to measure individual players’ and teams’ potential and success. But in the past fifteen years, a revolutionary new standard of measurement—sabermetrics—has been embraced by front offices in Major League Baseball and among fantasy baseball enthusiasts. But while sabermetrics is recognized as being smarter and more accurate, traditionalists, including journalists, fans, and managers, stubbornly believe that the ""old"" way—a combination of outdated numbers and ""gut"" instinct—is still the best way. Baseball, they argue, should be run by people, not by numbers.

In this informative and provocative book, the renowned ESPN analyst and senior baseball writer demolishes a century’s worth of accepted wisdom, making the definitive case against the long-established view. Armed with concrete examples from different eras of baseball history, logic, a little math, and lively commentary, he shows how the allegiance to these numbers—dating back to the beginning of the professional game—is firmly rooted not in accuracy or success, but in baseball’s irrational adherence to tradition.

While Law gores sacred cows, from clutch performers to RBIs to the infamous save rule, he also demystifies sabermetrics, explaining what these ""new"" numbers really are and why they’re vital. He also considers the game’s future, examining how teams are using Data—from PhDs to sophisticated statistical databases—to build future rosters; changes that will transform baseball and all of professional sports.