Book excerpt: The basic elements of baseball remain essentially the same as they were when the first professional game was played in the 1870s. Changes in this sport--when they come--come slowly. In 1973, one of baseball's most drastic changes was legislated: American League owners voted to add one player to the traditional nine-man line-up, creating a "10-man game" in which a designated hitter (or DH) had a regular spot in the batting order, and he or a replacement for him batted for his club's pitcher(s) throughout the game. This change to baseball rules was approved in the hopes that DH's would provide a spark for the AL's sagging offenses; an explosion in hits, homers and runs would draw more people to their ballparks and enable their clubs to surpass the National League in the annual attendance race. This work offers a fascinating exploration of the history and place of the designated hitter in the major leagues.