Defensive Line: Ogunleye, Brown, Boone and Johnson vs. Mathis, Freeney, McFarland and Brock
Both of these teams run a gap control defense in which each individual has a hole to fill to stop the run and either falls into coverage or rushes the quarterback. The difference between these two units is monumental. The Colts defensive line played a big role in allowing a league-worst 173 yards per game during the regular season. The pass rush of the line was also not effective due to most teams pounding the ball. Indianapolis combined for a modest 20.5 sacks from their defensive line with Robert Mathis leading the way with 9.5 sacks.  The Bears defensive line managed 29.5 sacks despite having the service of Tommie Harris for only 12 games. Rookie Mark Anderson led the way for the Bears with 12.5 sacks and has been a disruptive force this playoff season. The Bears line also is part of a run defense that allowed 99.4 yards per game on the ground, ranking sixth in run defense. The Bears have a big edge here with their pass rush and run defense. EDGE: Chicago

Linebackers: Urlacher, Briggs and Hillenmeyer vs. Cato June, Gary Brackett and Gilbert Gardner
At first when you just look at the linebacker units, this should be a no brainer as to who has the edge.  Two Pro Bowl linebackers in Brian Urlacher and Lance Briggs anchor the Bears’ defense. Those two combined for 276 tackles and five interceptions while the Colts’ Cato June and Gary Brackett combined for 264 tackles and three interceptions. June and Brackett are solid linebackers, but Briggs and Urlacher have world class speed and are two of the best linebackers in the game. Both Briggs and Urlacher are very good in pass coverage and can sniff out any running back that tries to slip out of the backfield.  Urlacher almost caught Reggie Bush in the NFC Championship game on his 80-plus yard touchdown pass. At times Urlacher was lined up against Marques Colston and Reggie Bush and showed he is more than capable of guarding the slot receiver.  Briggs is one of the best outside linebackers in the game and benefits from playing next to a player like Urlacher. Despite the solid numbers the Colts linebackers put up, there is a strong edge with the Bears’ linebackers. EDGE: Chicago

Secondary: Cornerbacks: Nick Harper  and Jason David vs. Charles Tillman and Nathan Vasher
The Indianapolis Colts could be down a man in the secondary if Nick Harper can’t go next Sunday. Harper left the AFC Championship game against New England with an injured left ankle. He status remains unknown.  Harper is tied for the team lead with three interceptions. Marlin Jackson , a first round pick from 2005, would start in Harpers place if he is unable to go. Jackson has filled in for injuries in the secondary at both corner and safety and came up with the the game-clinching interception in last weekend’s win over the Patriots.  Jason David, the other Colts cornerback, is a decent and overall, Indianapolis doesn’t allow too many big plays with their Cover 2 defense. Charles Tillman has been the Bears’ best cornerback this season with 81 tackles and five interceptions. Nathan Vasher is also a very strong with three interceptions and 45 tackles on the season. The Bears’ cornerbacks have the ability to make more game-changing plays and are much better in run support then the Colts. The Bears are also deeper at corner with Ricky Manning as their nickel corner who can also make big plays. Manning was tied for the Bears interception lead with five. If Harper can’t play, the Bears have a big edge at the corner position due to their depth. EDGE: Chicago

Safeties: Chris Harris & Danieal Manning vs. Bob Sanders & Antoine Bethea

It is clear that Bob Sanders is a major key in the Colts’ rush defense. Sanders provides a physical presence in the middle of the field that was simply not there when he was injured. The Colts haven’t allowed a 100 yard rusher in the playoffs, and Sanders has played a key cog in that feat. Antoine Bethea has also been solid in the secondary with 90 tackles and an interception. The rookie sixth-round pick has been a pleasant surprise for the Colts. Chicago ’s Chris Harris has filled in nicely for the injured Mike Brown since the middle of the season. Harris had 54 tackles and two interceptions this season. Danieal Manning has started every game this season as safety with 70 tackles and two interception. Both Harris and Manning have been solid this season, but they have been venerable to overrunning plays as evident with Bush’s 88-yard scamper in the NFL Championship. Sanders is a difference maker in the Colts secondary and that gives them the edge at the Safety position. EDGE: Colts 

Overall Secondary: Both units have their strengths and weaknesses. The Bears are very solid against the run and do not allow big plays, while the Colts have been weak at times in assisting against the run, they too do not give up big plays. Both units are very young and if Nick Harper doesn’t play, neither starting secondary has a played over the age of 26 years old. The Bears have the edge at corner, while the Colts have the edge at safety. Overall, the units are even. EDGE:  Even