What matters at Phoenix: Keep calm and plan your restart

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What matters in today’s Cup race and how will restarts impact track position? Let’s dive into the analytics, trends and strategy that will shape the Instacart 500 at Phoenix Raceway (3:30 p.m. ET on Fox):

Wild restarts call for for deliberate driving

Incrementally, NASCAR and Phoenix Raceway have made restarts the defining characteristic of the 1-mile racetrack.

The location change of the start/finish line, the shift to 750 horsepower followed by the 2020 downforce addendum, the addition of a traction compound and the implementation of the choose rule were all deployed as methods for punching up restarts, especially at Phoenix, the site of NASCAR’s championship race.

The result is the two-lap window following each restart now serving as the sport’s equivalent to a jump-ball.

Across the last four Phoenix races, spanning two different downforce packages and containing one race utilizing the choose rule, the restarts contained prevailing common denominators:

  • The inside of the first row was the most reliable, its occupants, often leaders, retaining 71.4% of the time across 28 clean attempts; those in the outside retained position on 57.1% of attempts.
  • The outside groove was better across the first seven rows at maintaining position, doing so 67.4% percent of the time compared to the inside’s 51.5% rate. Last fall’s championship race saw relatively even 62.9-60.0% success rates, a potential impact of the choose rule’s implementation.

The entire restart dynamic allows quick comebacks for those buried in the field following optional or bad pit stops but the memorable, GIF-making gains are the exception, not the rule. Consider that the best single restart for each top-14 running position within the last two years was only duplicated three times:

While successful defense of the position itself is reliable, there are a number of factors driving the gains. Tire wear skews restarts, yes, but tires do not have eyes or hands on the steering wheel; Kyle Busch and Kyle Larson are repeat names on the chart, unsurprising given their reputations.

But how a Phoenix restart materializes, with cars shooting into a wide space — think of an upside-down funnel — is a bit deceiving. More options can be limiting, as the space doesn’t necessarily make for a better restart; similar to Pocono, Phoenix offers wiggle room on the apron, to the left of the inside line, but the outside groove is faster, the statistically preferred of the two. Drivers tend to explore space to their own detriment, while those with cogent plans for their restarts take advantage of wandering cars:

Against cars running three or four-wide on the lap-272 restart in last year’s spring race, Busch (the white Sport Clips-branded No. 18) committed to running the apron in the first two corners. This resulted in an unfettered lane, in which he took the fifth-fastest car on short runs that day from 11th to third. It was an efficient, measured maneuver running against the grain of panicked dancing.

Phoenix’s restarts look wild primarily because they were designed to look wild; however, they can also act as bountiful exercises for the smoothest operators.

Straddling the line between calm and chaos

How restarts factor into today’s result is dependent on the frequency of cautions (which set up restarts) and the timing of cautions (for potential late-race restarts). The spring race in 2020 saw both a high caution volume (3.2 clean restarts per 100 miles) and three restart attempts falling inside the final one-tenth of the race; the fall race contained a tame caution volume (1.6 per 100 miles) and ended on a 112-lap green-flag run.

How drivers react to the extremes varies. Kevin Harvick was universally good in 2020, averaging a 7.6-place finish in races with caution volumes falling below 2.25 per 100 miles and a 6.7-place finish in their more chaotic counterparts. But some have the tendency to skew one way or the other.

Ryan Blaney was five positions better in relatively clean races (an average finish of 12.3) compared to caution-filled races (17.3); his inverse was Erik Jones, who thrived in chaos (11.4) relative to his efforts in tamer events (18.0). The ability to straddle the line can assist on track like Phoenix that can easily flip between polar opposites:

Harvick, Denny Hamlin and Brad Keselowski proved the most malleable last year. For Keselowski, today’s pole-sitter, it’s another sign of a translatable competitive strength.

No more places to hide

A popular thought behind the parity through the first four races was that the early-season schedule, consisting of a drafting track, a road course, a unique 1.5-miler and a more traditional intermediate, was so eclectic that we shouldn’t mistake performance as a symbol of relevant competitive strength.

That may very well be the case; however, it’s an excuse that ends today. Phoenix is the first 750-horsepower oval of 2021, the track type made most important by NASCAR’s schedule shift in advance of the year. Phoenix again hosts the championship race this November, while 12 other tilts on tracks fitting this description comprise the 36-race slate. It’s an increase of three events coupled with a decrease in the number of non-drafting races on 550-horsepower tracks (from 20 to 16), magnifying its stature as a subject of offseason and in-season research and development.

Arguably, the two organizations under the most scrutiny are Joe Gibbs Racing and Stewart-Haas Racing. JGR failed in getting its fastest 750-horsepower team — the No. 19 with Martin Truex Jr. and crew chief James Small — eligible for the championship in the season finale, while fellow playoff drivers Busch (sixth) and Hamlin (seventh) fared worse than Truex’s fourth-place series-wide speed ranking. Truex trailed Chase Elliott, Joey Logano and Keselowski in overall speed on these particular tracks.

For SHR, Harvick saw a big deviation in speed across the different 750-horsepower facilities. His car ranked as the fastest in each of the Phoenix spring race, the second leg of Dover’s doubleheader, Richmond and the Bristol playoff race. It ranked 17th in the Martinsville playoff race and 10th a week later in Phoenix, a disappointment given the importance of those races and Harvick’s ubiquitous dominance for the whole of the year.

For certain, any big team curiously lacking speed today isn’t keeping cards close to the chest. It’ll indeed be a misfire, potentially indicative of the season to come. NASCAR limited wind tunnel testing and computational fluid dynamic simulations for all teams, and with R&D focus soon turning towards the Next Gen car, it’s not economical for any organization to invest heavily in improving a lame-duck machine in the eight-month gap between today’s race and Phoenix’s fall finale.

Nevertheless, this is a sport in constant evolution without limits on who get hired (and when) or how workaday research efforts lead to a discovery yielding a competitive advantage. In this sense, a lot can naturally change in eight months and probably will.