1. 2015 San Francisco 49ers On this list we have seen examples of great players retiring suddenly in their prime, losing big-time players in free agency, the stunning departure of top coaches at or near their peak and legal troubles bringing down elite talents. The 49ers had a combination of all of those factors this offseason, I couldn't find another example of a team having so many various factors resulting in so many huge hits to the roster: Coach Jim Harbaugh was chased off to Michigan, guard Mike Iupati, running back Frank Gore and others departed in free agency, offensive...