Roller Coaster Regular-Season Championship Battle Heads to Sonoma

Six races ago, William Byron looked like a near-certain lock to win the NASCAR Cup Series regular-season championship, and the 15 bonus Playoff Points that go along with it. However, heading into Sunday's Toyota/Save Mart 350 at Sonoma Raceway, Byron is anything but a lock to take the opening 26-race crown.

Byron comes into the 1.99-mile road course in Wine Country, fresh off the disappointment of a last-place (40th) finish in the Grant Park 165 at the Chicago Street Course after he suffered a clutch failure on the opening lap of the race in his No. 24 Hendrick Motorsports Chevrolet.

The latest rough outing equaled the fourth finish of 27th-or-worse for Byron over the last five races, which has allowed the battle for the regular-season championship to intensify with just seven races until the NASCAR Cup Series Playoffs begin.

After a fifth-place run in the Cracker Barrel 400 at Nashville Superspeedway, Byron extended his regular-season championship lead to 49 points over Kyle Larson, while Christopher Bell (-87), Denny Hamlin (-104), Chase Elliott (-105), and Tyler Reddick (-118) seemed completely out of contention.

Fast forward to the here and now, and the only driver from that grouping who appears to be a drastic longshot to contend for the regular-season championship is Bell, who ranks sixth, and is 67 points behind Byron.

Elliott, Larson, Hamlin, and Reddick have all clawed to within 50 points of Byron, and with a recent surge in performances, Elliott finds himself just 13 points behind Byron going into Sunday's race.

While Byron has faltered in recent weeks, the driver of the No. 9 Hendrick Motorsports Chevrolet has yet to finish a race outside of the top-20 this season, and a 16th-place result last weekend at the Chicago Street Course marked the driver's worst finish since another 16th-place run at Texas Motor Speedway at the beginning of May.

Over the last four races, which included Elliott's first trip to victory lane since last season, the Dawsonville, GA native has recorded an average finish of 6.25. For sure the momentum seems to be swinging in Elliott's direction, and Sonoma Raceway is a track that suits Elliott's driving style quite well. While Elliott hasn't scored any of his seven career NASCAR Cup Series road course wins at the California track, but aside from an engine failure at Sonoma in 2019, Elliott has been ultra-consistent at the track.

When you remove the 37th-place finish due to the engine failue, Elliott has averaged a finish of 7.43 through his other seven career starts at the track, and he comes into this weekend's race on a back-to-back top-five finishing streak at Sonoma Raceway.

Larson, who sits just 19 points behind Byron, has the best track record at Sonoma of any of the regular-season championship contenders. Larson is the defending winner of this event, and he has found victory lane at Sonoma Raceway twice in 10 attempts.

While Hamlin (-43 points) isn't known as much of a road racer, the third-place driver in the championship standings is coming off of a fourth-place result at the Chicago Street Course following a last-place start to that event. He also has four top-five finishes, including a runner-up finish to Tony Stewart in 2016, and seven top-10s. The only potential issue for Hamlin is mechanical stability.

The driver blew an engine in his opening lap of practice last week in Chicago, and he blew an engine at the end of the opening lap of this race a season ago. If his engine can hold together though, he could have a decent result on Sunday.

Reddick (-48 points), who hails from Corning, CA, hasn't had the best career record at Sonoma Raceway, but he is widely regarded as one of the best road racers in the NASCAR Cup Series. Reddick's career-best finish at Sonoma did come last year in the form of an eighth-place finish after he led 35 laps in the race. Perhaps last year's effort, coupled with some newfound momentem (back-to-back top-five finishes at Atlanta and Chicago) is the signal that he's ready for a big breakthrough on Sunday.

While all of the aforementioned drivers come into the race on some sort of hot streak or established past success at Sonoma, Byron doesn't.

In addition to his rough five-race skid that he enters this weekend, Byron has just one top-10 finish through six career NASCAR Cup Series starts at Sonoma Raceway, and has a career average finish of just 22.0.

With all of this being considered, there's a very realistic chance that Byron, who has led the NASCAR Cup Series championship standings for 16 of the 19 races in 2025, walks out of Sonoma not as the point leader.