Home field gives the edge to Chicago

In breaking down the NFC title game, it's easy to make a case for the Saints' winning. Drew Brees is the more seasoned quarterback. The Saints have a powerful running game and an explosive passing attack. Sean Payton was coach of the year.

But here are the five reasons I think Chicago will win the NFC Championship Game on Sunday and advance to Super Bowl XLI:

Home sweet home: The Bears are playing at home, in the cold and in their elements. The playoffs have been so close this season that wacky things happen. The Seahawks won a home game when Tony Romo botched the game-winning field goal snap. It's been a playoffs filled with crazy plays and weird turnarounds. Because of that, the security of having the home crowd is extremely important in these close games. The Bears' crowd was a factor late in the game against the Seahawks, when Seattle was trying to drive for a game-winning field goal. The home team in the past two NFC championship games has advanced to the Super Bowl. The home team in the NFC has won five of the past seven games. Home field still rules in the NFC.

Back on the defensive: It might not be scientific, but the Bears are due for a good defensive game. Since the loss of defensive tackle Tommie Harris to a torn left hamstring, the Bears' defense has been pretty average. Instead of giving up 14 or fewer points, the Bears have given up more than 21 points in five straight games. This team was not built to allow that many points. But the solid play by defensive tackles Tank Johnson and Ian Scott has to be encouraging to Lovie Smith. Both players are on a mission. Johnson is trying to make Bears fans forget about his myriad off-the-field issues. Scott is playing for a new contract because he'll be an attractive free agent this offseason. When Harris was dominating games, the Bears were almost impossible to move the ball on. Johnson and Scott can't come close to Harris' disruptive ability, but they should be able to cause enough problems to make it tough on the Saints.

Well-coordinated plan: Offensive coordinator Ron Turner is doing the right thing with the offense. He knows Rex Grossman's confidence is fragile. He knows fans will turn on the quarterback if he makes too many mistakes. So Turner is emphasizing the run more. It's the right thing to do. He has Thomas Jones, who is a solid one-cut runner. Jones makes a decision on which hole to run through and hits it hard. Turner also has Cedric Benson, who is a pounding north-south runner. The more success the Bears have running the ball, the less they will have to rely on Grossman's arm. The run also sets up the Bears' play-action passing offense, which should give Grossman the opportunity to hit on a couple of big passing plays. Grossman has the arm and skills to play in a shootout, but if Turner can manage the game with the run, the Bears should come out on top.

Cornering the market: Bears cornerbacks are better than people think. Charles Tillman might have some bad games, but he is a talented cornerback and when he's on he plays at a Pro Bowl level. Remember some of his games against Randy Moss when Moss was with the Vikings? Tillman played Moss as well as any cornerback in the NFL. Nathan Vasher went to the Pro Bowl last year and had another good season. Both corners are also physical enough to help out on the run. Brees is a master of trying to play games with opposing cornerbacks. As long as Tillman and Vasher don't get faked out, they should hold up well in this game. It would hurt the Bears if Joe Horn plays because he's a veteran who knows all the tricks of the receiving trade. But even if he does play, Tillman and Vasher have an experience edge over rookie Marques Colston and Devery Henderson that will play to the Bears' strength.

Tipping the scales: The way officials let defensive backs play can minimize the difference in ability between quarterbacks. Drew Brees has a big edge over Grossman, but that could be minimized by the officials. Completions percentages by quarterbacks in the playoffs have dropped from 64 percent two years ago to 57.1 this season. Why? In my opinion, secondaries are being allowed to get away with more physical coverage. The NFL doesn't want playoff games riddled with penalty flags and coaches know this. They will tell their defensive backs to try to get away with as much as possible. While this obviously could hurt Grossman, too, I believe it will have a bigger impact on Brees and the Saints. The reason is the Bears' secondary has more talent and is better suited to take advantage of the way the officials call the game. If Brees is just a little bit off, it takes away what should be a big advantage for the Saints.

John Clayton is a senior NFL writer for ESPN.com.