This book ranks the greatest players in history overall and by position by using the All- Pro Awards and recognition that they received during the era in which they played. This subjective technique was necessary given the difficulties of ranking players of different positions and eras all on one list such as skill players verse lineman from 1923 to 2013. Many of the greatest players in history had relative lengthy careers which is significant due to the violence of the game. The book identifies many players who suffered from concussions, other medical difficulties and even died on the field. It also addresses the mistreatment of amatuer athletes in the sport. College athletics is the only business in America which is allowed not to pay its employees.