The inverted cover two is one of the most effective secondary schemes in football, but it is also one of the more difficult schemes to run.
Why is it so difficult?
The safety involved has to have the cover skills to handle the initial thrust of the play, and it is incredibly easy to get burned if your safeties do not have the speed to make the switch and stick with the receiver.
In a nutshell, the inverted cover two is a variation of the cover two defense that most NFL teams employ in pass coverage. The difference between the two is that pre-snap the corner lines up inside of the receiver while the safety is over the top outside. Right before or after the snap the corner and safety essentially switch responsibilities as the corner bails out to cover the deep pass and the safety comes up to cover.
The switch is most effective post-snap and is much harder to perform unless the safety is capable of running with a receiver in coverage. When employed against a team with a potent vertical passing game it is highly effective in shutting off the outside, and deep passing game.
The perfect example would be in the first half against the Arizona Cardinals in Super Bowl XLIII. Larry Fitzgerald was virtually nonexistent in the first half of that game due to this very set involving Troy Polamalu and the Steelers’ corners.
It proved to be so effective in thwarting the vertical passing game of Arizona that it left the Cardinals completely frustrated going into halftime.
Like any defensive scheme, it has its weaknesses, and it leaves the middle of the field vulnerable with a single linebacker covering the center of the field. That weakness was a fact that the Cardinals exploited in the second half of Super Bowl XLIII throwing to Fitzgerald over the middle for record-breaking numbers.
While it would not behoove the Steelers to run the inverted cover two with any type of consistency in terms of percentage of plays, Polamalu affords them the opportunity to use it quite effectively against teams that try to stretch the field vertically.
Something the Steelers will see regularly from the revamped Baltimore and Cincinnati offenses in the AFC North, and versus the New Orleans Saints in primetime this season.