Having a detailed plan of attack for Empty is something all defensive coordinators need to carry when going into a game versus a Spread team. An Empty formation stresses the defense in many ways by placing three WRs to one side and aligning two the other direction. This 3×2 set “zeros” the box, meaning it forces the defense to cover down to every wide WR. Regardless, if the defense leaves a linebacker(s) in the box, the offense has created an advantageous situation where the defense must run blitz or “max” coverage to overwhelm the offensive front.
Most defenses will carry three types of schemes versus Empty: Cold, Warm, and Hot pressures. In a “Cold” pressure the defense will use line stunts to create one-on-ones for the defensive line while dropping eight (or seven if a four-down) into coverage. This type of thought process maxes out the coverage ability and bets on the front to win with games. “Warm” pressures create man blocking upfront with five-man pressures. By sending five defenders the DC has guaranteed the offensive line must account for every defender.
The man-blocking creates one-on-ones for the defenders. Win one of those and the defense can get to the QB. Coverage wise, the defense can either run man to the pressure and zone away or run single-high coverages with no “Rat” or hole player in the middle (This is Cover 0 in Saban). Finally, “Hot” pressures sound exactly like their name, the defense is sending the maximum number of defenders, creating a man free somewhere along the line. Blitz coverage (or man) is ran behind it with the assumption that the ball is coming out HOT!
When defending a team the runs a good amount of Empty, a DC must understand what the offense is trying to do out of the formation conceptually, but more importantly, how are they protecting with the offensive line. Max pressure will almost always trigger slide protection. Offenses can slide either way, usually to the best pass rusher. This ensures that the one player is free off the edge (below). By knowing this, the secondary can tighten up and trigger on short routes. Any long developing route will lead to pressure. Pressing in this situation is probably not the best because the offense can hit a quick-strike Fade route with no help deep. Better play off-man or Bail (look like press then work deep).