FS Thomas, Seahawks' physicality key cover-3 defense
Seattle coach Pete Carroll's defensive objective is to stop the run at all costs.
If that means putting strong safety Kam Chancellor in the box and relying on free safety Earl Thomas to hold down the middle of the field by himself, so be it.
Don't expect that to change for Super Bowl XLVIII against the Denver Broncos.
The Seahawks have used their twist of the cover-3 defensive scheme to become one of the most dominant units in the league.
Seattle finished the regular season tied for seventh against the run (101.6 yards per game), first against the pass (172.0) and first overall (273.6).
What makes Seattle's cover 3 unique is the physical nature of cornerbacks Richard Sherman and Byron Maxwell and nickel back Jeremy Lane at the line of scrimmage. All three play bump coverage and want to be physical, something not typically associated with other zone-oriented defenses.
The cover 3 is a zone scheme that requires the back seven to cover an area rather than an individual. It is a basic defense that has been productive for the Seahawks since Carroll arrived in 2010.
In the cover 3, three defenders split the back, or top, of the defense into thirds, while four underneath defenders are responsible for shorter routes such as curls and flats.
The key to success is having a free safety who can cover a lot of space. Thomas is considered the best free safety in the league because he is responsible enough to chase intermediate routes.
Thomas in the deep middle allows the Seahawks to put the physical Chancellor near the line of scrimmage to create an eight-man box. The defense also allows more players to drop into coverage compared to the cover 2. Chancellor and middle linebacker Bobby Wagner are responsible for stopping the run.
However, if there is one place the cover 3 is vulnerable, it is in the seams. And with a quarterback the caliber of Peyton Manning, the Broncos are sure to test the Seahawks' signature defense.