Today's NASCAR race at Phoenix International Raceway could amount to a coronation for points leader Tony Stewart and, by extension, car owner Joe Gibbs. A strong finish by Stewart combined with poor showings by challengers Jimmie Johnson and Carl Edwards would essentially clinch a second NASCAR championship for Stewart and a third for Gibbs, who has had a busy fall indeed keeping alive the playoff hopes of his other team, the Washington Redskins.

But given the structure of NASCAR's points system, as well as the savvy of the racing operations behind Johnson and Edwards (which have won seven championships between them), it's doubtful that the outcome of today's Checker Auto Parts 500 will prematurely settle the championship and far more likely that it will ramp up the drama heading into the Nov. 20 season-finale in Homestead, Fla.

Nothing would delight NBC executives more or quite so clearly vindicate architects of NASCAR's 10-race postseason, which was devised two years ago to ensure drama down to the stretch of the seemingly interminable 36-race season. Its inaugural year did just that, with the battle between Johnson and Kurt Busch for the 2004 title coming down to the last lap at Homestead, where Busch won it by eight points.

With two races remaining in the 2005 season, Stewart is the man to beat. He holds a 38-point lead over Johnson, who drives a Chevrolet fielded by Hendrick Motorsports, and a 77-point lead over Edwards, who campaigns in a Ford for Roush Racing, the five-car operation that has won NASCAR's last two championships.

It's no surprise that Stewart and Johnson are in the mix for the title and $5 million champion's payout. The fresh-faced Edwards is the contender no one would have predicted when the 2005 season dawned.

Competing in just his first full season in stock-car racing's elite ranks, the 26-year-old Edwards still can't believe his good fortune to have landed a job with one of NASCAR's top teams. And he's unabashedly giddy over their improbable success together, performing celebratory back-flips off the windowsill of his No. 99 Ford after each aw-shucks victory. On the heels of four victories (and four back-flips) -- including back-to-back wins at Atlanta and Texas in recent weeks -- Edwards has vaulted over all four of his more seasoned Roush Racing teammates to claim third in the standings and a legion of adoring fans.

With his broad smile and Midwestern modesty, Edwards has none of the self-destructive angst that marred Stewart's early stock-car racing career, nor does he have a trace of Johnson's smugness or swagger.

"He's such a breath of fresh air to the sport because I don't think that kid has a care in the world about anything," said Stewart, 34. "I wish I could be a lot like him. It's nice to see a guy that absolutely is enjoying every aspect of his life right now."

Johnson claims to be enjoying his pursuit of Stewart, but it remains to be seen how happy he'll be if he finishes second in the standings for a third consecutive year. Still, it's hard to feel sorry for a guy who has never known mediocrity since landing a ride at Hendrick Motorsports at age 26 with the backing of four-time NASCAR champion Jeff Gordon, who is part owner of Johnson's race team. Johnson has yet to finish worse than fifth in the Nextel Cup standings, having had the benefit of first-class cars, pit crews and crew chief from the start. Edwards, of course, has enjoyed the same advantage at Roush Racing.

But with two races remaining, both face a daunting challenge in trying to erase Stewart's 38-point lead.

The most points a driver can gain or lose in a single Nextel Cup race is 156 (190 is the maximum available, assuming the winner also leads the most laps; the last-place finisher gets 34 points).

Still, it's not easy to gain ground -- particularly when the leader isn't taking many risks.

Take last week at Texas, where Johnson finished fifth. Instead of making a big leap in the standings, he gained only five points because Stewart finished sixth. And that's why Stewart has been so hard to run down, because he's putting more stock in finishing well (he has had 18 top-10 finishes in the past 20 races) than in winning.

For Stewart, it has been an acquired skill rather than an instinctive one.

The Indiana native started racing at age 7 and has excelled in nearly everything on wheels, including go-karts, midgets, sprint cars, Indy cars and stock cars. He has been so consumed by racing, at times, that nearly everything else has fallen by the wayside -- from romantic relationships (he is one of NASCAR's few bachelors) to minimally acceptable social skills. Under Gibbs, however, Stewart has polished his rough edges without dulling his competitive zeal. Time and tutelage haven't so much de-fanged him as taught him when to bare his teeth.

"If you wreck the car trying to maintain a spot or get a spot that you think you need, it's risk versus reward," Stewart explained last week. "The risk outweighs the reward at that point."

Tony Stewart is aiming for his second Cup title. But he must hold off hard-charging Jimmie Johnson and Carl Edwards.