Dixon, Wheldon, Castroneves and Kanaan roll off as odds-on favorites

Danica Patrick, left, and Tony Kanaan are both looking to win the Indy 500 for the first time. Darrell Ingham/Getty Images

INDIANAPOLIS -- The sun is expected to shine over Indianapolis Motor Speedway on Sunday.

Both literally and figuratively.

Rain washed away more than 50 percent of the scheduled practice time over the past two weeks for the competitors in the 92nd Indianapolis 500 (noon ET, ABC), but clear skies are predicted for race day.

The forecast is improving in general for the IndyCar Series. With a debilitating 12-year battle for political control of the sport finally in the rearview mirror, positive attention is again being directed at American open-wheel racing.

And on Sunday, the IndyCar Series will be showcased on its biggest stage.

There's nothing to suggest that the 2008 Indy 500 will be an extraordinary race -- though if Danica Patrick wins, the reaction will definitely be out of this world.

Certainly Patrick, who drives for the powerhouse Andretti Green Racing team, has an excellent shot at winning on Sunday. But four other drivers stand out as even more likely to drink the victor's milk and potentially cash a check for more than $2.5 million -- a 40 percent increase from 2007.

Target Chip Ganassi Racing teammates Scott Dixon and Dan Wheldon, Team Penske's Helio Castroneves and AGR's Tony Kanaan are the IndyCar Series' most experienced and respected drivers, and Sunday's winner will in all probability be determined from that foursome.

"Last year it was down to six guys and two of them [2006 Indy 500 winner and season champion Sam Hornish Jr. and 2007 Indy 500 winner and season champion Dario Franchitti] left this year," Kanaan observed. "Anybody can win this race, but if you go by facts or statistics, I think it's going to be played between the four of us."

Three of the four drivers are former IndyCar Series champions -- Castroneves, the dancing, fence-climbing Brazilian, is not, but he does own two Indy winner's rings.

Wheldon won the 500 and the IndyCar championship in 2005. In fact, the past three Indianapolis winners went on to claim the season points title.

"Out of the four guys, me and Dixon are the only two who haven't won at Indy," Kanaan said. "But it's not fair to say we're due, because this track doesn't owe anybody anything."

Dixon has been the man to beat, setting the pace in most of the practice days that were not rained out. After enduring yet another afternoon of rain Friday on Carb Day, the New Zealand native was relieved to hear that Sunday's activities look like they will go off on schedule.

Tony Kanaan

Out of the four guys, me and [Scott] Dixon are the only two who haven't won at Indy. But it's not fair to say we're due, because this track doesn't owe anybody anything.

-- Tony Kanaan

"You want to go out there and get it done with because we've been thinking about it a long while," Dixon said. "I can't wait to get in the car and race."

The first stint promises to be interesting, because the track will be "green" after the latest round of rain and the temperature could be warmer than it has been for most of the month.

The only time the temperature reached 80 degrees was May 6, the very first day of full-field practice. AGR's Marco Andretti paced practice that day ahead of Kanaan and Dixon.

If a team misses the initial setup and the race starts with a long green-flag stretch, a driver could lose too much ground to make up. The days of a driver making up a lap after falling behind early -- like Rick Mears did in 1988 -- are in the past.

"We're just going to take it cautious and make sure we get through it and try and maybe sit back a little bit," Dixon said. "We'll see what our options are. I want to see what the car is like in traffic early on, as well. We're just going to see what comes."

Wheldon said that the predicted different race day conditions shouldn't have much effect on the race.

"My theory around here is that if you don't know it by Carb Day, you're never going to have it," said the Englishman. "You can certainly fine-tune it in the race with all of the pit stops you have."

IndyCar Series vice president of competition Brian Barnhart claimed he is not worried despite the lack of practice time and the presence of 11 rookie drivers.

"Even with the challenges we've had weatherwise, we're in excess of 30,000 practice miles," he said. "If the temperature here on Sunday at 1 o'clock is in the low 80s, this place is going to get hot and slick and they're going to need a lot of downforce."

Hot or cool, the big question is whether anyone outside of the IndyCar Series' three main superteams (Ganassi, Penske and AGR) can challenge for the victory.

Even if Dixon, Kanaan, Wheldon and Castroneves falter, the next group of potential winners is comprised of their teammates: Penske's Ryan Briscoe (who qualified on the outside of the front row), and AGR's Patrick, Andretti and Hideki Mutoh.

Patrick and Andretti both came tantalizingly close to winning the 500, only to see it slip away in the closing stages -- in Andretti's case, literally on the last lap in 2006.

A victory by either young American star (or by rookie Graham Rahal of Newman/Haas/Lanigan Racing, though that is much more of a long shot) would result in a bonanza of attention for the IndyCar Series.

Outside the big three superteams, the strongest potential candidates to win are Panther Racing's Vitor Meira, the most prominent winless veteran driver in the series; Tomas Scheckter, who has been limited to a part-time schedule this year with Luczo Dragon Racing; and Newman/Haas/Lanigan's Justin Wilson, probably the strongest driver/team combination to come into the IndyCar Series this year from the defunct Champ Car World Series.

As always at Indianapolis, a number of one-off entries made the race. And while they won't be a threat to win, drivers like Davey Hamilton, Buddy Lazier, John Andretti and Alex Lloyd provide compelling story lines. A top-10 finish for any of them would be a worthy achievement up against the likes of Penske, Ganassi and AGR.

Truth is, IndyCar racing is much like NASCAR and Formula One in that the sport's top teams dominate the action more than ever.

That's not likely to change on Sunday.

John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.