1. They don't give up big offensive plays
The Steelers' defense has played up to its No. 1 ranking in the league for most of the season. And the AFC Championship Game was no exception. This unit simply doesn't allow itself to be consistently beaten by the game-breaking throws that Kurt Warner completed with ease to Larry Fitzgerald in the NFC title game. For one thing, the complex zone-blitz scheme of Steelers defensive coordinator Dick LeBeau should be able to generate enough pressure on Warner to limit his time and ability to find Fitzgerald and his other receivers. Warner has the experience and quick release to handle blitzes well, but the Steelers' blitz, led by Defensive Player of the Year James Harrison, will present a severe challenge. Pittsburgh's secondary, anchored by dominant strong safety Troy Polamalu, should be able to hold its own in coverage against Fitzgerald and Anquan Boldin.
2. They can stop the run
The Cardinals' offense has a newfound dimension in the explosive running of Edgerrin James, to go along with the effective rushing of rookie Tim Hightower. But the Steelers have the league's second-best run defense. They did a good job of making the Ravens one-dimensional by holding them to an average of 2.9 yards per carry. The Cardinals rely heavily on their outside speed on the ground. However, the Steelers defense has enough athletic players who are fast enough to prevent James and Hightower from consistently turning the corner for big gains. The Cardinals try to open the run with their passing game. If the Steelers can establish their run defense, the Cards' ability to make big plays through the air, like they did against Philadelphia, will be limited. And once Arizona's offense becomes one-dimensional, it will likely be a long day for Warner.
3. They run the ball effectively
True, the Ravens stuffed Pittsburgh's ground attack, holding Willie Parker to 2.0 yards per carry. But the Ravens had the NFL's second-ranked defense and are third against the run. Arizona's defense ranked 19th overall and 16th against the rush. True, the Steelers ranked 23rd in the NFL in rushing offense. Still, they have demonstrated they can move the ball effectively on the ground when they make a concerted effort to do so, as was the case in their divisional-round victory over San Diego. The Cardinals defense has done a nice job of stopping the run during the postseason, but it isn't nearly as talented, nor is its scheme as complicated as Baltimore's. The Steelers don't have to dominate on the ground. They simply need to run well enough to provide balance to their offense. If they get physical up front (which they are more than capable of doing) and Parker trusts his considerable physical ability, they should be able to run the ball well.
4. They have more Super Bowl experience
It was only three seasons ago that the Steelers won their fifth Super Bowl. Twenty players from that team are on the current squad, including Ben Roethlisberger. Big Ben was only in his second season then. He has since grown and matured considerably as an NFL quarterback. He has become more of a leader and understands what it takes to win big games. Granted, the Cardinals have a Super Bowl MVP and two-time Super Bowl quarterback in Warner. However, this will be the biggest game that most members of his supporting cast have played; the Cards have only five players with Super Bowl experience. And that is a factor. The Steelers are unlikely to be overwhelmed by the experience, from all of the media attention to the many demands (especially tickets) that family and friends place on them. It's a different story for the Cardinals. Also, once the game begins, the Steelers will have their experience in Super Bowl XL to draw upon.
5. They have the edge in coaching
Mike Tomlin and Ken Whisenhunt are both second-year coaches, so the experience factor is a wash. However, Tomlin has done a tremendous job of keeping the Steelers at the same high level of competitiveness that existed when Bill Cowher was their coach. Certainly, Whisenhunt merits kudos for what he has done with the Cardinals, but his team did experience a late-season slump after clinching the NFC West early. Whisenhunt does know Roethlisberger well, having guided him when Whisenhunt was Pittsburgh's offensive coordinator. But Big Ben also knows his former coach. The real coaching advantage the Steelers have is with LeBeau. His defensive genius is usually too much for any opposing offense to handle, and the Cardinals are no exception.