Fantasy football strength of schedule swings considers what defenses actually allowed last year and then applies it both to last year (to see how truly easy or tough a schedule was) and this year. And then it compares the two to show how much tougher a schedule is or isn't. Bottom line - if a schedule is roughly the same strength as last year and no other dynamics are at play, then a player should end up about the same. If a player had a big 2011 but his schedule was far easier than this year, then he's most likely due for a downgrade. And if a player excelled against a bad schedule in 2011 and now has a great one, man - grab that guy.