After weeks of fretting over who would make it into the playoffs, the good news is that the field of 16 championship-chasing drivers is finally set. The bad news? Just about every playoff driver can now immediately shift to worrying about being in the top 12 in three weeks‘ time. Forget about feeling comfortable: There‘s always heightened intensity at this stage of the season, and it can only rise from here.
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To help quantify who is under the most pressure — and who has the greatest opportunity to alleviate it for themselves — we are dusting off our playoff simulator model from last season to run 10,000 alternate versions of how the next 10 races might play out. This year‘s version has a few improvements, headlined by the use of the more predictive Driver Rating metric (rather than pure finishing quality) as the backbone of the predictions. For more about how the system works, read here — or otherwise, scroll down to see the initial forecast odds and find out which drivers have no sooner made the playoffs than they are right back on elimination watch.
Unsurprisingly, three of the four lowest-ranked drivers in the initial playoff point standings are also among the most likely names to be knocked out: Austin Dillon, Alex Bowman and Josh Berry. The exception among the lowest-ranked drivers is Tyler Reddick, who has a surprisingly strong 68 percent chance to advance despite currently sitting a point below the cutline. At the same time, Ross Chastain is down at 53 percent to make the Round of 12 despite entering the playoffs a point to the good.
What gives? For one thing, Reddick has been in better form than Chastain this season, despite having one fewer win. The former leads the latter in top-five finishes, average finish and — most importantly for our predictive purposes here — average Driver Rating, with the No. 45 car handily topping the No. 1 in that regard, 88.1 to 75.4. With two ovals to work with this round, where Reddick has been far better than Chastain this season, it helps explain why Ross is an underdog despite the more favorable situation in the points.
Still, both drivers are unquestionably under huge pressure starting this weekend at Darlington — and the simulations back up that feeling. Because Reddick has a strong history there, and is expected to be among the favorites, he can‘t afford to have a weak Southern 500 finish and still be in a solid position to advance this round. If Reddick finishes outside the top 20, for instance, his odds to make the Round of 12 fall from their current 68 percent level to just 44 percent, the biggest drop-off of any driver in simulations where they finish outside the top 20 on Sunday evening:
Such downside risk is one very obvious version of pressure — the kind where you don‘t have the luxury of an off-day at a track where you‘re supposed to do well. But there‘s also the pressure to take advantage of a chance to boost your odds. Shane van Gisbergen could gain 19 points of advancement probability with a top-20 finish at an oval, where he‘s tended to struggle (43.7 average Driver Rating) this season. Austin Dillon‘s chances of advancing could pick up a whopping 31 percentage points if he finishes among the top 10 on Sunday. And nobody‘s odds are more certain to change, one way or the other, than Chastain‘s between now and the end of the Southern 500.
We can quantify that by using one of our favorite data points that falls out of these simulations — the “leverage index” for each driver in a race. What does that mean, exactly? Borrowing from the same concept in baseball analytics, we can calculate the average swing in a driver‘s advancement odds — positive or negative — resulting from all possible outcomes he might have. The result is perhaps the best single measurement of pressure, as it captures the “do-or-die” nature of any given race for a driver, causing their odds to shift dramatically regardless of the circumstances.
Going back to Chastain, he faces the highest leverage of any playoff driver right away in Darlington, with an average change of +/- 17.7 percentage points in his odds to make the Round of 12 across all simulated outcomes. He gains 29 points with a top 10, but he loses 27 points if he finishes outside the top 30 — just to provide a few examples of how much Darlington will potentially move his advancement needle.
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Berry and Dillon aren‘t far behind Chastain in the leverage department, and they should each be rivals to watch all round long. But the biggest Round of 16 rivalry in terms of leverage — combining the swing in one driver‘s advancement odds depending on if another makes or misses the Round of 12, weighted by the likelihood of each outcome — is Josh Berry versus Alex Bowman. Here‘s a breakdown of each driver‘s chances to advance, conditional on the other driver advancing (or not):
In the simulations, there was only a 28 percent chance that both Bowman and Berry could simultaneously escape the Round of 16, while there was a 55 percent chance that one would make it out while the other didn‘t — and even a 16 percent chance that both would fail to advance.
Most likely, that means the two will be locked in a bitter fight that starts as soon as the green flag drops at Darlington, part of a Southern 500 that will set the tone for the playoffs as a whole: every lap carries big-time playoff consequences, and the only guarantee is relentless pressure from the very start.