The remaining half of the 2025 NASCAR Cup Series Championship 4 field is set to be determined this Sunday afternoon at Martinsville Speedway in the Xfinity 500.
Six drivers are set to battle for the two remaining spots alongside Joe Gibbs Racing teammates Denny Hamlin and Chase Briscoe in next Sunday afternoon's winner-take-all championship round at Phoenix Raceway.
Joe Gibbs Racing's Christopher Bell and Hendrick Motorsports' Kyle Larson are both well above the cut line heading into the Xfinity 500, meaning that they are both likely safe unless one of the four drivers below the cut line wins Sunday's 500-lap race around the four-turn, 0.526-mile (0.847-kilometer) "Paperclip" in Ridgeway, Virginia.
It's why Bell was actually listed as the championship favorite at FanDuel Sportsbook heading into the week, and none of him, Hamlin, Briscoe, or Larson were listed with odds longer than +370.
Meanwhile, none of the other drivers had odds shorter than +1200, as they are all in likely must-win situations.
Is NASCAR's championship longshot really a longshot?
Team Penske's Ryan Blaney was listed at +1200, ahead of Team Penske's Joey Logano and Hendrick Motorsports' Chase Elliott at +2000. But Hendrick Motorsports' William Byron, who is ironically the top driver below the cutoff and could actually still technically get in on points, was listed as a +3000 longshot.
And even after taking pole in Saturday's qualifying session, his odds have only shifted to +2000, placing him level with Logano and Elliott – still ahead of nobody else.
This is despite the fact that he, like Blaney was earlier this week, is now the outright favorite to win Sunday's race at +300.
Sure, you can't really differentiate Byron from the other seven contenders simply by saying he's a former Phoenix winner, because six of the other seven have all won at the Avondale, Arizona venue also. And the only one who hasn't is Blaney, who still won a championship there in 2023.
Additionally, seven of the eight drivers have won at Martinsville, and the one who hasn't, Briscoe, is already locked into the Championship 4 anyway, thanks to his win at Talladega Superspeedway.
But Byron is a two-time Martinsville winner, with both wins coming in the Next Gen era, and he is now the outright favorite to win Sunday's race (and thus advance to the Championship 4) after taking pole. Yet he is still considered a longshot to win the title next weekend. Is that +2000 value too good to pass up?
A full Martinsville starting lineup can be found here.
Full NASCAR Cup Series championship odds can be found here and are subject to change.
NBC's live coverage of the Xfinity 500 from Martinsville Speedway is scheduled to begin at 2:00 p.m. ET this Sunday, October 26. Begin a free trial of FuboTV now and don't miss any of the action from this year's round of 8 finale!