JOLIET, Ill. -- So this is it.
Two hundred laps. Three hundred miles. Four drivers, but only one series champion.
Helio Castroneves, Sam Hornish Jr., Dan Wheldon and Scott Dixon will all lay it on the line during Sunday's Peak Antifreeze 300 at Chicagoland Speedway (ABC, 1:30 p.m. ET), but only one of them will walk away with the 2006 IRL IndyCar Series crown and the check for $1 million that goes with it.
It's the closest championship battle in Indy Racing League history, with the lead quartet separated by just 21 points -- roughly the difference between winning and finishing fifth.
Castroneves heads to suburban Chicago with a single-point advantage over his Marlboro Team Penske teammate Hornish. Target Ganassi Racing's Wheldon and Dixon are separated by just two points, but Wheldon is 19 points behind series leader Castroneves.
Those two intra-team battles that will play out are one of several subplots to watch for during the IRL season finale. For example, Castroneves is the only one of the four who has not won the IndyCar Series championship. Penske Racing has never captured an IRL crown since joining the series in 2002. And let's not forget that there will be 15 other drivers on the track trying to win the race even if the championship is out of reach for them.
That might be the case, but Chicagoland is likely to be a repeat of every other IRL superspeedway race in 2006 -- a red-and-white wash by Penske and Ganassi. A combination of Penske and Ganassi drivers has finished 1-2 at every 1.5-mile track this year and they have led 959 of 1,000 laps on those five circuits.
Castroneves and Hornish each have two wins at 1.5-mile tracks, Hornish's coming in the two most recent races at Kansas Speedway and Kentucky Speedway. On that track configuration this year, Hornish has led 396 laps, followed by Wheldon with 296 and Castroneves with 264.
Dixon, the 2003 IndyCar Series champion, has led only five superspeedway laps all year. So with all due respect, let's make him the first one voted off the island. The question then is whether Wheldon -- who has shown speed and tenacity on 1.5-mile tracks this year but hasn't had much racing luck since winning the season opener at Homestead-Miami Speedway -- can wrestle the championship from the Penske drivers.
"As a team we've let some results slip away that we perhaps shouldn't have, but that's all part of a championship," Wheldon said. "When you consider what we've done and the fact that we're only 19 points out of the lead, that gives you a lot of motivation to go into this race and just try and dominate and then see what happens."
Points leader Castroneves was his usual bubbly self during a media teleconference featuring the championship contenders earlier this week. His main task on Sunday is to finish ahead of his teammate.
If he does that, a fourth-place finish guarantees him the title even if Wheldon wins the race and leads the most laps.
"I feel pretty confident, even if the odds [are] a little bit different than they say," Castroneves said. "I've been in so many hunts in the championship. It's a good opportunity and what will be will be. We just have to be there in the end and be smart."
There's an unstated acknowledgement between the other championship contenders that Hornish is the man to beat. Ten of his 18 IndyCar Series race wins have come at 1.5-mile tracks, and he has a knack for prevailing in the photo finishes those tracks produce.
Hornish and Castroneves have battled for the title in the season finale before, albeit not as teammates. In 2002 while driving for Panther Racing, Hornish beat Castroneves by a nose at Texas Motor Speedway to win the championship. Hornish has also won twice in five Chicagoland starts and his average finish is 2.6.
"Obviously I know there is going to be some very strong competition, but Dan and Scott still have a great opportunity," Hornish said. "I'm not only watching for Helio, I'm watching both of those guys.
"You know, we're all here to race and we're all here to win. Hopefully I'll do the right thing. To be able to win the championship and the Indy 500 in the same year would be unbelievable."
What of the rest? Panther's Vitor Meira has come closest to beating the big four on high-speed tracks this year, coming second to Castroneves at Michigan International Speedway.
Andretti Green Racing has been surprisingly uncompetitive on fast tracks this year, so don't look for a challenge from that camp. Dario Franchitti might have driven his last race for the team; the Scot suffered a minor concussion when he crashed a vintage Jaguar XK-E at the Goodwood Revival race meeting and will be replaced at Chicagoland by A.J. Foyt IV. It will be interesting to see how young Foyt fares in the most competitive ride of his IndyCar Series career.
Rahal Letterman Racing hasn't set the world on fire this year, either, so a repeat of Danica Patrick's pole-winning performance from 2005 probably isn't in the cards.
However, Danica's new team, Andretti Green Racing, might use the weekend to announce details of her 2007 sponsorship package in the hometown of Motorola Corporation.
John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.