What matters in Atlanta: Tire wear makes speed deficiency difficult to mask
What matters in today’s NASCAR Cup Series race and how will heavy tire wear impact the influence of speed on the result? Let’s dive into the analytics, trends and strategy that will shape the Folds of Honor QuikTrip 500 at Atlanta Motor Speedway (3 p.m. ET on Fox):
Thanks to tire wear, elite speed is required
The relative randomness of the correlations between speed ranking and finishing position that’s popped up on 550-horsepower tracks the last two seasons apparently has no claim to Atlanta Motor Speedway.
Tire wear — cars on old tires will approach two seconds worth of degradation today — is the factor keeping the running order honest. Last year’s race saw the three fastest cars as the three highest finishers, helping drive the correlation coefficient to a +0.9, symbolizing a strong relationship between the two stat categories. The assured result for those with elite speed is a breath of fresh air following some truly maddening correlations, such as last summer’s races in Texas (a +0.5 coefficient) and Kansas (+0.6).
To that end, speed will be impossible to fake and difficult to mask. Those with the best speed are easy favorites while those without might be limited in magnitude of track position gains made via strategy.
Hendrick Motorsports appears well suited for the 1.54-mile track, with William Byron’s No. 24 car ranking as the fastest on 1.5-mile facilities this season while Kyle Larson’s No. 5 ranks first through the first five races in average median lap time rank and Chase Elliott’s No. 9 sports the best top-end speed, ranking first in average best lap time rank:
But as we saw last weekend, initial speed isn’t final speed. The No. 19 car of Martin Truex Jr. held the 12th-fastest median lap time in Phoenix’s first stage, forcing a diagnosis and adjustment from crew chief James Small. Their troubleshooting worked. Truex ranked as the fastest driver across the final 118 laps, capable of distancing himself in clean air and utilizing the statistically non-preferred outside groove on a restart for the go-ahead pass on Joey Logano.
In lieu of practice time, Small utilized the early runs of the race as a de-facto shakedown, searching for balance in a car that’d been fine-tuned since last November.
“I just don’t think people understand how hard it is with no practice to try to be perfect every week,” Small said. “It takes a lot of effort, a lot of refinement, everything we can do just to be good off of the truck. We started bad. Some of our assumptions were off.
“All offseason we worked (on the Phoenix setup). Once we got the car balance right … you saw all the dividends for all the work we put in, the changes were made.”
The revelation from Small regarding the amount of work Joe Gibbs Racing put into its 750-horsepower program, and Phoenix specifically, is deflating for teams with mildly competitive speed attempting to tread water against the sport’s most prominent organizations. If Small’s on-the-fly battle for balance tapped into a car already optimized for Phoenix, it’s doubtful any balance found during a race will provide a similar boost for those who didn’t unearth a similar race-winning setup prior to unloading.
Pit strategy might not win this race, but it can certainly improve a result
The green-flag strategy known as short-pitting is the mathematically advantageous tactic today, with beneficiaries hopping onto fresh rubber sooner than surrounding opposition. This maneuvering allows drivers who recently pitted for tires to cut into deltas against — or overtake completely — the nearest cars in the running order, taking advantage of the near-two-second degradation.
To this point, Drew Blickensderfer, on behalf of Michael McDowell, has tallied the most positions, 27 in all across nine cycles through the first five races. Just three of those positions, though, came on non-drafting ovals.
Chevrolet teams for Chase Elliott, Alex Bowman and Austin Dillon have earned 11 positions apiece on non-drafting ovals this season, a shared top rank among all programs, while Randall Burnett, on behalf of Chevrolet driver Tyler Reddick, procured single-cycle gains of two or more spots on five separate occasions, the most among all crew chiefs.
The roots of Chevrolet’s success through pit strategy are tied to Eric Warren’s use of machine-learning software for pit stop decisions while he oversaw competition at Richard Childress Racing. Now GM’s NASCAR programs director, Warren’s reach includes most Chevrolet teams, the early returns for which include four affiliated crew chiefs among those with the biggest quantifiable output.
While good strategy can improve the probability of a result, the result won’t deviate wildly from the car’s overall speed ranking in Atlanta. To wit, Mike Shiplett created a race-high nine positions through three green-flag pit cycles on behalf of Cole Custer last year. Custer finished 19th with the 24th-fastest car, an example of the tire wear hanging a low ceiling on those attempting to strategize their way out of middling speed.
The outside restarting groove is equal to, if not better than, the inside groove
Today marks Atlanta’s first race since the inception of the restart choose rule; however, the two most recent races were still impacted by interesting choices.
The leader opted for the inside groove on all 12 starts and restarts dating back to the 2019 race. For the most part, these decisions saw good returns, with an 83.3% retention rate and occupants averaging a 1.83-place running position two laps after the restart:
But the notion that the outside groove was ignored across the board is curious, considering its equivalent retention rate (83.3%) and smaller positional loss (-0.25 spots per attempt). While any leader should accept a success rate higher than 80%, the second-place runners in Atlanta, originating exclusively from the outside groove, had solid footing. This went beyond the front row.
Rows 2-7 saw outside groove retention rates range from 66.7-100% while those occupying the inside groove defended position at rates ranging from 16.7-50%.
Since drivers and teams don’t tend to fix what isn’t broken, the inside line will most likely be coveted again today for restarts, but the outside groove should prove a formidable foil.