The NASCAR Cup Series Championship 4 field is set, after William Byron won the Xfinity 500 at Martinsville Speedway on Sunday. He's set to join Denny Hamlin, Chase Briscoe, and Kyle Larson in competing for a title at Phoenix Raceway.
All four drivers should be fairly evenly matched, and it's anyone's guess as to who brings home the trophy. Each one of them has a uniquely compelling case in which it's easy to see a world playing out in which they are crowned the 2025 Cup Series champion.
Byron's argument is as strong as they come, for one simple reason: he has momentum on his side.
William Byron could follow in some legendary footsteps after statement Martinsville win
When it comes to momentum carrying over to the championship, the best race to win in the round of 8 is generally its first one. Five times since NASCAR's modern playoff format was introduced in 2014, the winner of Race No. 33 has gone on to win the title, which bodes well for Denny Hamlin.
However, the schedule's penultimate event has also predicted the champion on three occasions: Kevin Harvick in 2014, Chase Elliott in 2020, and Ryan Blaney in 2023. All three of them were not only first-time champions, but it was the first time they'd qualified for the Championship 4 (in Harvick's case, by default).
Byron has been to the Championship 4 before, in each of the past two seasons, but in both 2023 and 2024, he transferred on points. This time, he not only won his way in, but he did so in a manner much different from the way the driver of the No. 24 Chevrolet generally tends to win races.
Byron is one of the more conservative drivers in NASCAR, and seldom does he ever find his way to the front through emerging in a late-race duel. His team is elite at executing to put him in position to win, and he feasts on that track position like no one else. He's a defender, rather than an aggressor.
On Sunday, though, he had to be an aggressor. Two luck-induced poor results to start the round of 8 put him in a must-win situation at Martinsville, and despite having the dominant car, he found himself mired in traffic midway through the race following a pit strategy shakeup.
He was able to drive back through the field and outmuscle Blaney for the win in the closing laps, earning arguably the most impressive victory of his Cup Series career.
For Blaney and Elliott, their Martinsville wins were just as crucial to their title campaigns as their results at Phoenix Raceway the following week. They proved they could power through with their backs against the wall, forced into a situation where all of the responsibility laid upon the driver to get the job done.
Byron's struggle to overcome adversity has been the subject of criticism throughout his career, but on Sunday, he flipped the script. Now we'll see if, like those before him, the confidence boost can carry him forward to his first Cup Series championship.