Draft Watch: NFC North

Each Wednesday leading up to the NFL draft (April 22-24), the ESPN.com blog network will take a division-by-division look at key aspects of the draft. Today's topic: schemes and themes.

Chicago Bears

No matter what scheme they run, the Bears will have limited opportunity to find impact players in this draft without a first- or second-round pick. The Bears, however, have specific schemes on both sides of the ball that require special personnel attention. They don't run their "Tampa 2" defensive front on every play, but they still place emphasis on athletic interior linemen who can mount their own pass rush. And while they value coverage ability, they also need cornerbacks who are big enough to redirect receivers on the line of scrimmage before passing them on to the secondary cover man. Offensively, new coordinator Mike Martz needs quick receivers who run precise routes more than bigger deep threats. Running backs must also have above-average receiving skills to play in his system.

Detroit Lions

After three years in a defense that emphasized speed, the Lions now focus on size when it comes to linemen and linebackers. Defensive tackle Sammie Lee Hill, who weighs 330 pounds, never would have been a Lions draft pick under the previous regime. They aren't likely to select many 285-pound defensive tackles or 240-pound defensive ends. Defensive coordinator Gunther Cunningham wants his line to push back against pressure, not run around it. Offensively, the Lions are lucky to have a flexible scheme that emphasizes the strengths of their players. They don't need a prescribed height, weight or skill set for that side of the ball.

Green Bay Packers

Because they play the 3-4 defensive scheme, the Packers will keep an eye out for college defensive ends who are athletic enough to make the transition to outside linebacker in the NFL. They'll also look for college defensive tackles who could move to the end position in their scheme. And with Dom Capers as the defensive coordinator, you shouldn't rule out a wild-card draftee: A player with 'tweener skills who could be used in a creative way. USC safety Taylor Mays comes to mind. Offensively, the Packers look for linemen who can play multiple positions and can operate in a zone blocking scheme. And every offensive skill player, including tight ends and running backs, must have a high comfort zone in the pass game.

Minnesota Vikings

Under vice president Rick Spielman, the Vikings take a nuanced approach to the draft -- identifying specific players they want and then trading up or down in a round to make sure they get them. Second-round pick Tyrell Johnson (2008), a big and athletic safety the Vikings considered a perfect fit for a Cover 2 defense, is an example. They also prefer offensive players with experience running a version of the West Coast offense. That, for example, is why they traded up to get quarterback John David Booty in 2008. The offense Booty ran at USC has the same passing tree as the Vikings'.