In August 2012, Felix Hernandez of the Seattle Mariners pitched a perfect game against the Tampa Bay Rays, winning not with power but uncanny off-speed pitches. For Terry McDermott, the extraordinary events of that afternoon inspired this incisive meditation on the art of pitching. Within the framework of Hernandez's achievement, McDermott surveys the history and evolution of pitching, combining baseball's rich tradition of folklore with the wealth of new metrics from the statisticians who are transforming the way we think about the game. McDermott's book is also the personal story of a fan's devotion, first kindled by his father in small-town Iowa and now carried forward with the same passion by his own daughters.