The most difficult NFL DFS weekends are those on which there is no clear value. You look at a slate and find yourself drawn toward plenty of guys on the high end of the price range, but on the low end you see nothing.
We usually run into five or six such weekends each season (or rather: about 30% of our NFL DFS lifetime is spent dealing with such slates), and while these are the most challenging weekends for us, they are also the most challenging weekends for others — which gives us a nice edge when we figure out . . .