The late great Walter Payton was an iconic figure and arguably the greatest professional football player of all time. He was beloved by millions because of his heroic work ethic and the immense respect he had for the game. He played with dignity and amazing grace, and always made it seem so effortless. On the field, he was an incredible thoroughbred, but off the field, he was complex and elusive. Columnist Jeff Pearlman of SI.com explains.