Two deep safeties. It’s the coverage that has befuddled the Cowboys offense and tormented Dak Prescott since the Denver game last year. It’s nothing exotic. It’s a basic coverage. Yet, it’s been the Cowboys’ kryptonite. Its weaknesses are the seam between the safeties and the corner route on the sideline. But, for whatever reason, Dak doesn’t throw to either spot. Consequently, the Cowboys were given an early playoff exit when they could neither run against a four man front or …