Who is the driver most likely to get surprise win at Richmond?

If you want to fill out the final five positions in your Chase for the NASCAR Sprint Cup grid, there’s a simple solution — just do the math.

Odds say the 16 drivers currently in Chase-eligible positions heading to Saturday’s Federated Auto Parts 400 at Richmond International Raceway (7:30 p.m. ET on NBCSN) will be the same 16 who start the Chase with a chance to win the championship.

But that’s not to discount the possibility of a new winner throwing a wrench into the works by stealing a victory at the .75-mile short track. It’s happened before. In the first year of the Chase (2004), when the field was limited to the top-10 drivers in the standings after 26 races, Jeremy Mayfield led the most laps and won at Richmond to knock Jamie McMurray out of the 10-race playoff.

McMurray is one driver whose participation in the Chase is a virtual certainty. Last Sunday’s Bojangles’ Southern 500 at Darlington left him one point short of an outright clinch, but all McMurray has to do at Richmond is take the green flag to assure his participation in the Chase for the first time in his NASCAR Sprint Cup Series career.

“Going back this time, knowing that we will just have to start the race to be locked into the Chase is a great feeling,” McMurray said. “I have been the guy on the bubble going to Richmond and not come out on top, so I’m glad to know that I won’t experience that again this weekend.”

If one of the 11 drivers who already has won a race this season repeats at RIR — and that’s a strong likelihood, given that the series hasn’t seen a new winner since Kyle Bush took the checkered flag in race No. 16 at Sonoma in late June — McMurray, Ryan Newman and Jeff Gordon all have their tickets punched, and Paul Menard qualifies with a finish of 38th or better, 39th if he leads a lap and 40th if he leads most laps.

The scenario is more complicated if Richmond produces a unique winner. Under that circumstance, Newman must finish 31st or better (exclusive of laps led), Gordon 17th and Menard ninth to exercise control of their own destinies.

With four drivers assured of making the Chase on points (five if there isn’t a new winner), let’s look at the most likely possible surprises at RIR.

Clint Bowyer — His worst nightmare is a new winner who isn’t Clint Bowyer. If there’s a repeat winner, all Bowyer has to do is retain any part of his 29-point lead over Aric Almirola and 31-point advantage over Kasey Kahne, respectively, to advance. In the case of a new winner, Bowyer could still advance by overcoming a 10-point deficit to Menard or an 18-point deficit to Gordon. Or Bowyer could simply win the race. Two of his eight career victories have come at RIR, and his average finish there is 11.4. By way of comparison, Menard’s average finish at Richmond is 23.4, with just one top five (fifth in the 2013 fall race). So Menard, like Bowyer, will have to sweat out the prospect of a unique winner on Saturday night.

Aric Almirola — Only Almirola (16th in the standings) and Kahne (17th) have mathematical chances to catch Bowyer and advance on points, but both prospects are extreme long shots. Almirola’s chances of grabbing a Chase spot with a victory are equally bleak. His average finish at the track is 18.1, and in seven starts at RIR, he has one result better than 10th (eighth in the 2013 spring race).

Kasey Kahne — Eleventh-hour heroics are nothing new to Kahne, who bulled his way into last year’s Chase with a victory at Atlanta in the 25th race of the season. Like Almirola, Kahne’s shot at qualifying on points is remote at best, but a win isn’t out of the question. Kahne got the first of his 17 career victories at RIR. Then again, that was back in 2005. Since then, his average finish has trailed off to 17.2. But Kahne was sixth in the spring race this year to break a string of five straight results outside the top 10.

Greg Biffle — The “Biff” is one of 12 drivers who can lock up a Chase spot with a victory — and only with a victory — but the prospects of a radical reversal of fortune for the Roush Fenway Racing driver aren’t good. Biffle has struggled at Richmond, posting just two top fives in 26 starts while recording an average finish of 17.2.

Kyle Larson — To make the Chase, Larson must win his first NASCAR Sprint Cup Series race, and don’t dismiss the possibility. Larson has been fast in both practice and qualifying at Richmond, winning the pole in his first visit to the .75-mile track last year. If Larson and crew chief Chris Heroy can find a way to translate qualifying speed into race speed, Larson could be a contender, as he was last Sunday at Darlington. The bad news? Larson has only one top five so far this season, after posting seven last year.

Tony Stewart — Smoke’s chances for a victory aren’t as remote as you might think. True, the three-time series champion doesn’t have a top five to his credit this season, but he was up on the wheel last Sunday at Darlington, posting an average running position of 10th after spending a long stint in the top five. Stewart has three wins at RIR, none since 2002, but he has four second-place runs since then. Mistakes on pit road cost Stewart dearly at Darlington; if he finds his way to the front on Saturday night, the over-the-wall crew must shape up to keep him there.

Austin Dillon, AJ Allmendinger, Casey Mears, Danica Patrick, David Ragan, Sam Hornish Jr., Trevor Bayne, Ricky Stenhouse Jr. and Justin Allgaier all could secure a Chase spot with a win at Richmond, but there is nothing about their respective performances this season that suggests a victory is in the offing.