There are five drivers essentially competing for one spot in the Championship 4 entering Sunday's Xfinity 500 at Martinsville Speedway.
Christopher Bell and Kyle Larson locked up their spots with wins in the past two weeks, while William Byron is 30 points clear of the cut line and would need a disastrous race to fall below the top four.
Ryan Blaney is in a far more precarious position in the fourth spot, only 10 points ahead of Tyler Reddick. Another seven points back are Joe Gibbs Racing teammates Martin Truex Jr. and Denny Hamlin, who put themselves behind the proverbial 8-ball with poor performances at Homestead last Sunday.
"We've been behind the 8-ball before. I feel like we show up in these situations and put our best effort forward," Hamlin said. "I certainly feel like there is heavy motivation this week. We know what we're capable of. Now, we just have to go do it."
Chris Buescher, who sits in eighth, would need a win at Martinsville in order to advance to next week's championship race in Phoenix.
XFINITY 500
Location: Martinsville Speedway
Date: Sunday, Oct. 29, 2 p.m. ET
Distance: 500 miles on 0.526-mile short track
Defending champion: Christopher Bell
Cup Series leader: Bell
TV: NBC
Radio: SiriusXM NASCAR Radio
5 BEST BETS
Denny Hamlin (+325 at BetMGM)
Hamlin can secure a place in the Championship 4 with a win at Martinsville, a place where he has visited Victory Lane five previous times — tops among current drivers. The most recent of those came in 2015, but Hamlin has finished fifth and fourth in his past two Martinsville starts. "We're going to my best track," he said.
Kyle Larson (+725)
Larson has avoided the pitfalls that led to 8 DNFs throughout the course of the season, finishing no worse than 15th the past four races. And before a 31st in Texas, Larson had reeled off another trio of top-4 finishes. He is tied for the lead at the book with 9.9 percent of the total bets backing him to win Sunday, and Larson is third with 10.8 percent of the total money. He ran second to Bell in this race last year.
William Byron (+725)
Byron leads all drivers with six wins this year among his 20 top-10s, so those banking on a blowup come Sunday are facing their own long odds. Byron has only three DNFs this year, although he did finish 23rd at Martinsville during the spring after qualifying eighth. He's third with 8.3 percent of the bets backing Byron to win.
Martin Truex Jr. (+900)
The regular-season champion enters Sunday with his back against the championship wall, but Truex has won three of the past eight Martinsville races. After two poor starts at the track in the Next Gen car last year, he did run third during the spring race. Truex is tied with Larson with 9.9 percent of the total bets backing him to win this week.
"Martinsville looks so easy — it's just a small, little half-mile track, but it's so tricky with the concrete in the corners, and every time you go there, it's different," he said. "Running third there in the spring, I think we learned a lot we can use going forward and, hopefully, we can find some of that old magic we had there a few years ago again this weekend."
Ryan Blaney (+1100)
Blaney sits in the final Championship 4 spot and enters Sunday with a bull's-eye on his back as the bottom four drivers attempt to leapfrog him. After qualifying 31st in the spring race, Blaney rallied to finish seventh. He also has a win at Talladega and a second at Homestead among his past four races, with Blaney finishing 12th or better in each one. He's the book's third biggest liability this week, drawing 9.2 percent of the money at enticing odds.
LONGSHOT PICK
Christopher Bell (+1700)
Yes, Bell leads the playoff standings, but he's only tied for the 10th shortest odds this week despite being the defending champion of this race and running first and second the past two weeks. However, those results were on large tracks. Bell ran 16th at Martinsville in the spring after qualifying 22nd. He is the book's biggest liability this week, with the public jumping on his lengthy odds with a field-leading 15.9 percent of the money wagered.
—Field Level Media