Since the start of the new millennium, the road to the Super Bowl in the AFC has gone through either New England or Indianapolis. If you beat the Patriots or the Colts, you have a chance.
The NFC is different. The field is wide open. NFC teams don't have to score enough points to beat a Peyton Manning or Tom Brady.
NFC teams can make Super Bowl runs by becoming one of the best in the league in defense or by simply becoming a good running team. Defenses play a bigger role in winning NFC titles because of the difference in scoring. Maybe that's one of the reasons it's been harder for the NFC to win a Super Bowl in recent years.
In the NFC, you can build one good unit and have a chance. The Bears built a great defense. They went to the Super Bowl. The Saints hired Sean Payton and signed Drew Brees. They became a contender.
So what is there to look forward to in NFC training camps this summer?
NFC East
Philadelphia Eagles -- After being down for one year in 2005 because of a Donovan McNabb injury and the Terrell Owens turmoil, the Eagles are back atop the NFC East. The key to camp is watching McNabb. He's the key to their season. Supposedly, he enters camp with his knee at about 85 percent. Considering the severity of the knee injury, that's not bad. Carson Palmer was probably about 80 percent last year and he had a good season. Andy Reid should allow the running game to develop during camp knowing McNabb won't have all of his mobility.
Dallas Cowboys -- Wade Phillips is a players' coach and he has good players. It will be fun to see how he puts this team together. Watch the defense. Bill Parcells limited the number of blitzes and made his defensive linemen anchor the line and wrestle with blockers. Phillips will turn the defensive players loose with more blitzes and more plays in which linemen can shoot the gap. It will also be important to see how QB Tony Romo handles his first training camp and how he looks as the team's leader.
New York Giants -- Is everybody happy? The mood of the team will be the key to Giants' camp. Tom Coughlin is fighting for his job, but he's also tired of hearing veterans complain. He wants his players to be positive. Will Michael Strahan show up happy? Can Plaxico Burress and Jeremy Shockey make it through camp without any blowups or controversy? This is also an important summer for Eli Manning, who has to assume more leadership and proficiency in the offense.
Washington Redskins -- Players have been raving about the development of quarterback Jason Campbell. He has had an excellent offseason, but outsiders have to see how he is developing as a starter. Campbell didn't have a great pocket presence in his first year, but he was in a tough spot. Now, this is his team and his time to prove his ability.
NFC South
New Orleans Saints -- Drew Brees showed everyone last summer that the offense was in good hands. In his second year as head coach, Sean Payton needs to develop the defense. The Saints continue to make changes to strengthen the team at linebacker and in the secondary. The Saints also need to come out of camp healthy at defensive tackle. That's one of the biggest areas for concern, particularly with Brian Young opening camp with a broken foot.
Carolina Panthers -- To make a playoff run, the Panthers have to be able to run the ball. If John Fox is able to put together the running attack in camp, it will be his most important accomplishment this summer. The Panthers need a great camp from DeAngelo Williams, who will compete against DeShaun Foster. The Panther lost two starting offensive linemen to injuries in last year's opener and it destroyed the whole continuity of the running game. The Panthers need to come out of camp running.
Atlanta Falcons -- The Falcons are a mess. Quarterback Michael Vick isn't allowed to show up at camp because of his dogfighting case. Bobby Petrino has to rally his troops behind Joey Harrington and assess whether he needs more quarterback help. He also needs to find leaders. Who knows how long Vick will be gone? Petrino needs to reset the hierarchy of this team in camp.
Tampa Bay Buccaneers -- This is an important camp for Jon Gruden, which makes this one of the best stops in the league. Gruden is a gamer and the pressure is on. He needs to win, and he has a very good chance of making a run. He has an experienced quarterback in Jeff Garcia. Now in his third season, Cadillac Williams should be able to improve an underachieving running game. The team also is coming off its first defensive draft in years, so Gruden has a chance to filter some young players into the aging unit.
NFC North
Chicago Bears -- Despite winning the NFC title, the Bears will be trying a lot of new things this summer. Rex Grossman is working on his fundamentals. Cedric Benson takes over at halfback. Offensive coordinator Ron Turner will try some two-tight end sets with Greg Olsen and Desmond Clark. Another key is watching how well DT Tommie Harris plays coming off a major injury from a year ago.
Green Bay Packers -- A year ago, Brett Favre said the Packers had some of the best talent he's been around since the mid 1990s. Everyone thought he was crazy, but the young Packers turned in an 8-8 season. This is virtually the same team as last year. The biggest problem is at halfback. Ahman Green left for Houston. Favre needs to develop a running game in camp.
Detroit Lions -- Jon Kitna created some excitement by saying the Lions will win at least 10 games this year. The excitement is the offense. The Lions can't afford a long holdout by Calvin Johnson because he's the key to the three-receiver offense. Halfback Kevin Jones is coming off a major foot injury, so it will be interesting to see how Tatum Bell and T.J. Duckett fit into the running game. Bell has speed. Duckett has size.
Minnesota Vikings -- The trip to Vikings camp is pretty simple. Watch the offense. The key to the season is to determine whether quarterback Tarvaris Jackson is ready to be a winning NFL starter. He's talented but he's raw. If he's too raw in his first full camp running the offense, the Vikings might have to scramble for quarterback help before the season. What should be fun is watching the running game. Adrian Peterson and Chester Taylor form perhaps the best one-two punch in football.
NFC West
Seattle Seahawks -- Mike Holmgren is known for having great offensive teams, but the defense will be the most fun to watch. The Seahawks signed defensive end Patrick Kerney to add a pass rush. Watching him mix rushes with linebacker Julian Peterson will be fun. The Seahawks revamped the secondary by adding safeties Deon Grant and Brian Russell, and will mix in young cornerbacks Kelly Jennings and Josh Wilson.
San Francisco 49ers -- Other than the Patriots, the 49ers had the best offseason of any team in football. Mike Nolan gets to display the new talent in camp. Nate Clements will help the secondary. As much as the 49ers know they need improvement on defense, it will be the offense that will be the show in camp. Alex Smith will be throwing the ball to second-year tight end Vernon Davis and newly acquired wide receivers Darrell Jackson and Ashley Lelie.
Arizona Cardinals -- Not since Alex Gibbs went to Atlanta has there been this much excitement about an offensive line coach. Russ Grimm goes to the Cardinals with the idea of running the ball 30 to 35 times a game. It will allow Edgerrin James to move back into the limelight and make it easier on second-year quarterback Matt Leinart.
St. Louis Rams -- The Rams added WR Drew Bennett and TE Randy McMichael to an already-loaded offense. Everyone expects quarterback Marc Bulger to show up on time even if he doesn't get a new contract. He has plenty of offensive weapons, including halfback Steven Jackson, who wants to put together 2,500 yards of total offense.
John Clayton is a senior writer for ESPN.com.