For two years, Miguel Cabrera's numbers have stunned the baseball world. Cabrera, the Detroit Tigers' big-framed 30-year-old third baseman, won the American League Triple Crown in 2012, leading the league in batting average, home runs, and runs batted in—a feat no one had pulled off since Lyndon Johnson's presidency. This year, he didn't quite repeat the accomplishment. His power stats faded in September as he battled an abdominal strain, but his offensive production was actually better than it was in 2012.

In an era dominated...