Limited by a small payroll and, until July's lease extension, even uncertainty about his home ballpark, Athletics general manager Billy Beane is admittedly and necessarily "contrarian" in his views of roster construction.

Baseball's most famously frugal executive—there is a book you've probably heard about detailing his methods—is again the architect of a winning club. This year's edition of the A's sprinted out to the majors' best record at the All-Star break before a severe second-half slump meant settling for...