Under the NASCAR points system, a 15-point margin is less than the difference between a race winner and runner-up, and a 46-point margin is less than the difference between first place and eighth. For the three contenders left in the race for the Sprint Cup title, the mathematical possibilities seem endless, particularly once bonus points are taken into account. And yet, at the same time, it's all very simple -- winning the championship Sunday at Homestead-Miami Speedway may also require winning the race.

In the Chase era, it's never happened. Never has a driver under the current playoff format closed out a championship season by winning in South Florida, although two have come close. Carl Edwards won the 2008 finale but finished second, 79 points behind Jimmie Johnson, and Greg Biffle's victory in 2005 still left him 35 short of Tony Stewart. A double-victory celebration after the last race has occurred just six times in NASCAR history, and only once in the sport's modern era -- in 1998, when Jeff Gordon completed his epic 13-win campaign by sweeping the season's last two events, clinching the title with a triumph at Rockingham and winning the next week in Atlanta for good measure.

The Chase, though, has been another matter. As tight as that inaugural 2004 playoff was, a fourth-place finish in the finale was enough to secure the championship for Kurt Busch. But now, with the top two drivers separated by the closest margin ever at this point -- 15 points, compared to 18 in 2004 -- and with the third-place team promising to throw it deep all day, the route to the head table in Las Vegas may very well run through Homestead-Miami Speedway's Victory Lane.

"You always want to be the guy that makes the three-point shot, or the half-court shot at the buzzer to win the game, or kick the winning field goal or whatever it is," said Chad Knaus, crew chief for second-place Johnson. "This is the opportunity for one of these teams. Whoever goes to Homestead and gets it done is going to win the championship."

Of course, everybody likes their chances. Among the three title contenders, leader Denny Hamlin -- who is 15 ahead of Johnson and 46 in front of Harvick -- is the only driver to have won on the 1.5-mile oval, that victory coming a year ago this week in a finishing stretch that heralded him as a serious challenger for the current campaign. Homestead is one of Hamlin's better tracks, a place where he's finished inside the top five in all but two of his career starts, and where he can clinch his first title by finishing second and leading the most laps, or winning the race outright.

"If you look at stats, yeah, it's good. It looks good for us. If you look at history, it looks good for us. But you never know what can happen," Hamlin said last weekend after a Phoenix race where fuel-mileage issues forced him to stop late for gas, allowing his competitors to cut his advantage in half.

"This stuff that happened [at Phoenix] can happen [at Homestead] and you can't control it. We just hope to have a clean race [this] week and the best car win. That's all that we can ask for to crown the champ. That's the thing, I'm proud that we've stepped up our performance like we have over these last few weeks. I'm very proud ... to be able to do that. So I'm just going to continue to keep digging as hard as I can go and try to beat those guys. It's going to be tough. Those guys are going to be good. We see that every week. They're top-five. As far as I'm concerned, it's going to take a win."

Homestead is the only current Chase track -- and one of just four active Cup Series venues overall -- where Johnson has never won. In fact, no driver from his Hendrick Motorsports team has won there. Yet he's won two of the past three poles in South Florida, has finished inside the top 10 in six of his eight races there as a full-time Cup driver, and seems bemused by the theory that he's never before had to actually race for a championship on the final weekend. Johnson has led by hefty margins at this point in the season in each of the previous four years, his worst position over that span being 63 ahead of Matt Kenseth in 2006.

"I'm not sure why that's even relevant," Johnson said. "If you look at points accumulated over the course of a season, over a Chase, I think that will speak volumes to what kind of Chase took place. We've been competitive, but not as dominant as we've wanted all year long. At Homestead, we've got to go down there and race for it, that's no doubt about it. I continue to hear, 'The 48 hasn't had to race for it before.' We've raced for it all Chase long. Maybe at Homestead we've been able to protect. But we certainly know that's not the case this year. I love where we are. I love putting pressure on these guys, and I'm glad we cut their lead in half."

The two seasons he finished second in the final standings, 2003 and '04, Johnson's shortcoming wasn't Homestead -- he finished third and second, respectively, in the finale those two years. And yet, Knaus admits that one of his key concerns right now is the fact that his team hasn't been in this position before, at least not during their championship run.

"I think the biggest concern that I've got currently is that we haven't gone to Homestead to truly race yet," Knaus said. "We've gone down there with a bit of a protective mind-set, so I think that puts us a little bit behind compared to the other guys. Denny, he ran top-five most of the race last year. They had a good pit stop at the end, got some good track position, [were] able to win the race and that was a good job by them. We ran 15th to fifth the majority of the day, but never really had to get ourselves in a position where we had to push the car a whole lot. So we haven't had to be the aggressor there, so I think that puts us a little bit behind the eight ball."

And then there's Harvick, who comes to South Florida with absolutely nothing to lose -- the worst he can finish is where he is right now -- and promising to go for broke from the drop of the green flag. "We just have to be aggressive," he said. "That's been a great race track, statistically, which is something you guys [in the media] like to use. It's our best race track on the circuit, so we're looking forward to it."

Strangely enough, he's right. Although he's never won there, Harvick's average finish of 8.4 at Homestead is his best at any track on the circuit, and best among the three championship contenders. No wonder, when asked how he liked his chances in South Florida compared to the competition, No. 29 crew chief Gil Martin issued a succinct reply: "I think we're better than both of them," he said.

"I'm not taking anything away from [Hamlin and Johnson] at all. They're going to race really good there, too. What I mean by saying that is, that's just Kevin's kind of track. He runs well there, he's got a good record there, and I just say I think were going to be good. ... I'm just predicting were going to do everything we can to win this championship. We're not going to roll over and die. We're going to race hard, and we're not going to give anybody anything. If they do beat us, they're going to have to race hard."

That much is clear. And yet, in the final event of the closest championship race of the Chase era, racing hard might not be enough. On Sunday at Homestead-Miami Speedway, it might very well take one victory to ensure another.

"It's pretty straightforward," said Mike Ford, Hamlin's crew chief. "You go down there, and you go for a win."

The opinions expressed are solely those of the writer.