By Dan Durkin-

(CBS) It goes without saying that teams don’t exclusively run one coverage. There was a misconception that Lovie Smith exclusively ran his Tampa-2 coverage scheme during his time with the Bears. This wasn’t the case.

While that was the Bears’ base defense, like all other defenses in the NFL, the Bears ran a variety of split-safety and single-high safety looks. It just so happens that they had the appropriate personnel to run Smith’s Tampa-2 scheme with great effectiveness.

Along with defensive coordinator Leslie Frazier, Smith has brought the Tampa-2 scheme in his first year with the Bucs. At its core, it’s just a hybrid of a standard Cover-2 (two-deep safety) shell, with one variation — the middle linebacker (or “Mike”) serves as a middle seam defender. This means that the Mike carries the inner-most receiver as deep as he goes up the vertical seam.

Like any coverages, there are several ways to attack a Tampa-2 shell. Bears coach Marc Trestman has a variety of standard Cover-2 beaters in his playbook: smash, high-low and two verticals. But earlier this season, they saw some Tampa-2 looks against the Atlanta Falcons and attacked it with the dagger route.

So let’s go to the film room to take a closer look.

The Bears come out in 11 personnel in a 2-by-1 gun slot exchange formation, with a split-back backfield of tight end Martellus Bennett and running back Matt Forte.

The dagger route uses a clearout concept to occupy both the Mike up the middle seam as well as the deep safety on that half of the field. Slot receiver Santonio Holmes (green arrow) runs the clearout on this play. The No. 1 receivers (closest to the sideline) Brandon Marshall and Alshon Jeffery run dig routes that settle behind the underneath coverage.

In the backfield, Bennett and Forte run “check” releases, meaning they will check for a blitzer on their side before releasing into the flat as a checkdown option for quarterback Jay Cutler.

Notice the zone coverage drops for the Falcons defenders. Tampa-2 is essentially a two-deep, five-underneath coverage shell with the Mike backer occupying the middle of the field between the underneath and deep defenders.

Notice the voids that develop in the coverage, particularly up the hash marks behind the underneath middle hook defenders and the sideline over the top of the corners playing the curl/flat zone.

Holmes occupies both the Mike backer and the deep safety on the frontside of the formation, which leaves a void over the middle for Jeffery to settle into on his backside dig.

Cutler escapes the pocket and keeps the play alive long enough to find Jeffery, who has settled his route and completes a 19-yard pass on third down to move the chains.

Teams have had success this year “zoning out” the Bears by keeping a shell on top and forcing everything underneath. There are solutions for the Bears offense to this tactic that boil down to Cutler having enough time in the pocket to survey the field and receivers setting up in the soft spots of the zone.

Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter at @djdurkin.