Keeper strategy, sleepers/busts

Most people would assume the biggest difference in analyzing players in keeper formats and redraft leagues would be simply to look at player age. New Orleans Saints quarterback Drew Brees is old and St. Louis Rams passer Sam Bradford is not, so there you have it, Bradford is the better keeper-league pick. But he's not, and it's not even close. Sure, Brees' career will likely end before Bradford's, but even that isn't a lock, and assuming you want to win your league while both are active, you clearly want Brees.