Defenses and kickers are nearly impossible to predict bro. You just put one in and hope for the best bro.
Detroit's defense has been ranked pretty highly each week (at least better than the other option available to me). They got me 14 points through the 1st 4 games of the year.
I grabbed the Rams cause the Cards o-line sucks and got rewarded with 17 points last night. Anything you get from a defense is bonus unless you have a dominating defense and even they have off weeks.