Can anyone stop Jimmie Johnson from winning a sixth-straight title?

Johnson's dominance has frustrated competitors for half a decade. Even when he's appeared vulnerable -- as Johnson did last year -- he's won the championship. It doesn't matter who has challenged him. Matt Kenseth, Jeff Gordon, Carl Edwards, Mark Martin and Denny Hamlin have each finished second to Johnson one year but could not match Johnson's excellence for consecutive seasons.

It is a level of domination few teams in other sports achieve. The question is if it can continue.

With the title chase beginning this weekend at Chicagoland, Johnson has only one victory to his name. He's never had fewer than three wins entering the Chase in the previous five seasons. Questions about his pit crew remain.

People are also eyeing other drivers as favorites. Gordon has been strong this summer. He held off Johnson's charge two weeks ago at Atlanta, which some see as an indication that Johnson's reign could be fading. Others note that Kyle Busch and Kevin Harvick each have won a series-high four races, that Edwards has been dominant at times and that Brad Keselowski is among the hottest drivers in the sport. On and on the list goes.

It is easy for some to look at Johnson's recent incidents with Kurt Busch at Pocono and Richmond and believe that Johnson can be distracted by a feud, that Busch has found a way to get to Johnson. Saturday night, their antics continued. Busch got into Johnson and wrecked him. Johnson retaliated about 65 laps later.

"I'm just not going to let people run our race car over,'' Johnson said.

Drivers can't be afraid to fight on the track if they feel they've been wronged, but playing mind games with Johnson's team? Is that really the best path to a championship?

"The No. 48 is perhaps the mentally strongest team there is out there,'' Brad Keselowski said about Johnson's team. "I don't think anyone would argue that and they have speed. That's a lethal combination because when you have the mental focus that they have you can execute, and when you have speed, that's two of the three parts of the pie with the third one being a little bit of luck. They've had that, too, over the last few years.

"Certainly nobody knows if they'll have the luck this year, too. It doesn't mean it's going to be easy for anyone to beat them, but as far as time's concerned, eventually they've got to lose one, right? Eventually it's got to happen. But as far as where we're at with our team, I'm trying not to focus or prepare on just the No. 48. I think that's where everybody screws up, personally.''

Might Keselowski be conceding too much to Johnson's team by his approach? He doesn't think so.

"I don't believe in playing to other people's strengths,'' Keselowski said, referring to the team's mental toughness. "I play to their weaknesses and that's kind of where I was going with that."

Not everyone seems to take such an approach. Jeff Gordon says when he won his championships and dominated the sport in the mid-1990s, he saw the impact it had on other teams.

"Ray [Evernham] used to always say, a lot of times we would go to a track and have the competition beat before we ever got on the racetrack,'' Gordon said of the former crew chief, with whom he won three of his four titles. "If you can really perform at a high level consistently, then you get the competition looking at what you are doing, and paying attention and sometimes taking them off of their game and what they are capable of doing and that is another advantage. The No. 48 team has certainly been able to do that; everybody has their eye on them, everybody watches them.''

While it's natural to look at the best in any sport, Jeff Burton questions that way of preparing for the Chase. He says a team's focus should be elsewhere heading into the final 10 races of the season.

"In our sport, we go to different racetracks every week,'' said Burton, who missed the Chase this year after having been in it four of the past five seasons. "The Red Sox, although the outfield wall may be in different spots, the bases are all in the same place whether they're in Colorado, in Florida or in Boston. So they're really playing the opponent.

"We race more against the track. So, our main focus as race teams isn't a particular team, but it's the racetrack. If you go around that racetrack faster than everybody, then you're going to beat them.''

Yet, no one has been able to beat Johnson's team for five years. Johnson credits a level-headed approach -- one that has been tested by Kurt Busch in recent weeks -- as helping him become one of this era's top drivers. Johnson concedes that maintaining his success has been more difficult than many would think. He notes that as the Chase progresses, "the voices start, the thoughts start in your head. You will be challenged in every area as an individual and as a team.''

Kyle Busch, the No. 1 seed in the Chase for the Championship, and his team have not fared well with this challenge, either because of mechanical issues or questions about his mental ability even though he has a Nationwide championship. A slow start will lead to further questions about Kyle Busch and his team. A good start will erase those questions and allow him to challenge for a Cup title, which he's never truly done. His best finish in the Chase is fifth in 2007.

While drivers concede that a poor finish will hurt them even more with this new points system, the key will be to maintain one's composure through the ups and downs of the Chase. That's where Johnson has excelled. It's helped him win his championships a variety of ways.

He was ninth after the first Chase race in 2006 and rallied to win the first of his titles. He and Gordon traded the points lead three times in 2007 before Johnson took the lead for good three races from the end of the season. Johnson grabbed the points lead by the fourth race in 2008 and '09, and both times maintained it through the rest of the Chase. Last year, Johnson chased Hamlin, entering the season finale second in the points but rallying to win the title.

"Experience over the years has helped me focus in the right areas,'' Johnson said. "And I could have taken a negative turn and thought that we were in trouble and panicked. But from experience, and knowing how to make the right decisions, I stayed the course mentally and focused on the right things and it came through for us.

"In time you learn what to worry about and what's really important for you and your race team."

Worrying about one driver won't help Johnson win another title, but time might be a more challenging foe. As Keselowski says, at some point Johnson has to lose a title. Doesn't he?

"I'm a realist,'' Johnson said. "I know at some point we're not going to be the champion. I've thought about that a lot over the last four years to be honest with you. But I think that there is something within that that continues to make me hungry to succeed and also something within all of it has helped me enjoy what has been going on.

"We've already beat the odds. We've done things that nobody has done before."

Dustin Long covers NASCAR for The Virginian-Pilot in Norfolk, Va., The Roanoke (Va.) Times and the News & Record in Greensboro, N.C. His blog can be found here.