Analysis: Ranking NASCAR’s best on short runs, restarts


Short runs, the kind of which we’ll see in the final 10-lap stage of tonight’s NASCAR All-Star Race, can showcase the way in which teams choose to optimize their cars and a driver’s individual performance on restarts. Having both can act as a discernible identity for a race team.

In a subjective ranking of objective measures such as speed, restart performance and Production in Equal Equipment Rating in races ending with short runs, NBC Sports has identified the 10 best drivers and teams on short runs to this point in 2021.

MORE: All-Star format explained 

What you won’t see are teams relying on legacy performance — Chase Elliott’s restarting this year has dipped from its 2020 title-winning high point — or spots awarded for moments like Alex Bowman’s Richmond win, thanks to a superb restart, which was an outlier based on the totality of his short-run output this season.

What you will see are 10 of the most well-rounded short-run performers, with statistical rationale backing their place in the rankings:

  • Average speed ranking at the beginning of runs
  • Position retention rate, the percentage of restarts inside the top 14 in which a driver defends his or her initial running position in the two laps following a restart
  • The average net positional gain from within the top 14, usually ranging from -1 to +1
  • Production in Equal Equipment Rating (or PEER), a consideration of a driver’s race result that handicaps team and equipment strength in an attempt to isolate his or her contribution, in races concluding with short runs

Without further ado:

1. Brad Keselowski, Team Penske No. 2

There’s no better restarter right now, offensively or defensively, than Keselowski, whose 29 positions gained this season on choose-rule restarts towers over the next-best tally (Ryan Blaney’s five). His 75.93% retention rate on restarts is a boon to a team ranked ninth in speed at the beginning of runs (second among Penske’s four affiliated teams).

In pockets, he’s a delight to watch. His effort at Las Vegas Motor Speedway was nearly a record-breaking feat. He earned 26 positions within the two-lap window following each restart, with 14 of them from a launching point within the first seven rows:

Keselowski made short runs easy for himself during the season’s initial half, selecting preferred groove positioning on 59% of his choose-rule attempts. He’s capitalized nicely in races ending with a late restart, ranked fifth in PEER in that scenario, courtesy of a win at Talladega and third-place finish in Kansas.

2. Kyle Larson, Hendrick Motorsports No. 5

Larson’s team, led by breakout crew chief Cliff Daniels, ranks second in speed at the beginning of runs (and the fastest overall based on median average lap rank), but the driver is also an exceptional restarter, ranking third in position retention rate on choose-rule attempts (73.33%) and third in average positional net (-0.05 overall, +0.31 from the preferred groove).

Races containing late restarts, though, are a bugbear on paper, a notion Larson confirmed two weeks ago — “I just kind of wanted to cruise to the checkered flag” — regarding the prospect of seeing one in the Coca-Cola 600.

Ranking first in PEER in races without a late restart (with an average finish of 5.6), he ranks dead last in races with at least one (with a 22.2-place average finish), a staggering juxtaposition. With the sample size of the latter relatively small, his yearlong short-run performance suggests he deserves some benefit of the doubt going forward.

3. Denny Hamlin, Joe Gibbs Racing No. 11

Hamlin didn’t take advantage of an opportunity to rough up Joey Logano late in the Bristol dirt race, and he lost late leads on short runs at Martinsville and Richmond. But those moments only serve to muddy up the narrative.

In reality, Hamlin’s team is one of the five fastest this season on short runs. He’s an efficient restarter, ranked fifth in retention, eighth in net gain and second in net gain on non-preferred groove attempts, specifically. He sits second in PEER in races ending with a short run. Finishes of third, third and second in the aforementioned races is a testament to this kind of balance. While he isn’t the series’ best in any one category per se, he does well enough — without real weaknesses — to be dangerous regardless of how a race breaks.

4. Kyle Busch, Joe Gibbs Racing No. 18

With similar balance to Hamlin but less prolific numbers — sixth in retention and seventh in our scenario-based PEER — Busch’s lone win came in a race (Kansas) that concluded on a two-lap run. He’s one of four drivers averaging a positive positional net (+0.06) on all choose-rule restart attempts, ranked third overall.

His car ranks as the slowest among JGR’s quartet in speed at the beginning of runs, eighth overall in the series, a mark on which improvement could help lift Busch’s numbers to loftier heights and fetch better results.

5. William Byron, Hendrick Motorsports No. 24

Byron won a Homestead race culminating with a 60-lap green-flag run, but his restarting was influential to his dominance in the 400-mile contest. He earned 11 spots across six restart attempts, never once ceding position within the two-lap windows following each attempt, including his critical leap from sixth to second on the lap-208 restart:

In his first Cup season paired with Rudy Fugle, Byron ranks as the fastest driver at the beginning of runs. While his positional defense of late has been spotty — his 61.43% retention ranks 16th — he’s an earner when he’s on offense, averaging +0.06 spots per attempt and capable of turning late restarts into tangible results, ranked third in PEER in races ending on short runs.

6. Ryan Blaney, Team Penske No. 12

Ranked 11th in speed at the beginning of runs (and just 10th late in runs), Blaney isn’t working with an elite car when he’s putting up such big restart numbers. He ranks second in position retention (with a 73.77% rate) and second in average gain (+0.08 overall, +1.03 per preferred groove attempt).

He’s had an affinity for restarts since his early years in the Cup Series, something for which he credits his formative seasons in super late models, but this season, the 27-year-old has evolved into a more balanced racer — his surplus passing value, fueled predominately by long-run performance, is currently at a career-best level — so much so that his PEER splits favor races ending in long runs (like his lone victory in Atlanta). He ranks 16th in PEER in races containing a late restart.

7. Matt DiBenedetto, Wood Brothers Racing No. 21

DiBenedetto ranks first in PEER in races containing a late restart. That’s not a typo.

He proved himself an efficient restarter in his lone season with Leavine Family Racing and since moving into the Penske camp, he’s transformed into a premier short-run driver, currently ranked first in retention on 550-horsepower tracks and seventh across all choose-rule tracks.

The results driving his first-place PEER ranking, though, are relative to his equipment. His car ranks as the 18th fastest on short runs, a failing of the team to maximize its driver’s biggest strength.

8. Joey Logano, Team Penske No. 22

Ranked fourth in both short run speed and PEER in races containing a late restart, Logano’s performance has lacked the consistency of some of his closest competitors. His 64.41% retention rate ranks 13th in the series, shaky positional defense that was on display at Phoenix against the driver ranked directly below him here, but his 0.07-position net loss is enough to keep him viable (and ranks sixth overall) in these scenarios.

His savvy decision making is helping him stay competitive. He’s selected the statistically preferred groove in 56% of his choose-rule restart attempts.

9. Martin Truex Jr., Joe Gibbs Racing No. 19

Truex’s top highlight for the season came against Logano at Phoenix in what ultimately proved a result-defining restart. As Truex put it, “He drove in deep. I drove in deeper.”

The No. 19 car hauls on short runs, ranking third overall, but while Truex’s PEER split in races ending with short runs fares well (ranking sixth), his restart numbers have dipped into a pedestrian territory near the front of the field. He currently ranks 15th in position retention and 14th in net gain.

This isn’t a reason to panic (yet), because Truex is traditionally a productive restarter. A realistic improvement in these numbers before the end of the season would mold him into more of a force during the playoff stretch than he already seems.

10. Kevin Harvick, Stewart-Haas Racing No. 4

Harvick, regardless of his running whereabouts, tends to achieve balance or overachieve altogether, and that’s present in his short runs in 2021.

The 45-year-old has the seventh-best average positional gain (-0.16) and retention rate (63.93%) and eighth-best PEER split with the 10th-fastest car on short runs. Barring an uptick in raw speed, something on which Rodney Childers has worked diligently since the start of the season, the ceiling for improvement in the near term appears limited.

Appeal panel gives William Byron his 25 points back


William Byron is back in a transfer spot after the National Motorsports Appeals Panel rescinded his 25-point penalty Thursday for spinning Denny Hamlin at Texas.

By getting those 25 points back, Byron enters Sunday’s elimination playoff race at the Charlotte Roval (2 p.m. ET on NBC) 14 points above the cutline.

Daniel Suarez is now in the final transfer spot to the Round of 8. He is 12 points ahead of Chase Briscoe and Austin Cindric. Christopher Bell is 45 points behind Suarez. Alex Bowman will not race this week as he continues to recover from concussion symptoms and has been eliminated from Cup title contention.

NASCAR did not penalize Byron after his incident with Hamlin because series officials did not see the contact. Two days later, NASCAR penalized Byron 25 points and fined him $50,000 for intentionally wrecking Hamlin.

The National Motorsports Appeals Panel stated that Byron violated the rule but amended the penalty to no loss of driver and owner points while increasing the fine to $100,000.

The panel did not give a reason for its decision. NASCAR cannot appeal the panel’s decision.

The panel consisted of Hunter Nickell, a former TV executive, Dale Pinilis, track operator of Bowman Gray Stadium and Kevin Whitaker, owner of Greenville-Pickens Speedway.

Here is the updated standings heading into Sunday’s race at the Roval:

Byron’s actions took place after the caution waved at Lap 269 for Martin Truex Jr.’s crash. As Hamlin slowed, Byron closed and hit him in the rear. 

Byron admitted after the race that the contact was intentional, although he didn’t mean to wreck Hamlin. Byron was upset with how Hamlin raced him on Lap 262. Byron felt Hamlin forced him into the wall as they exited Turn 2 side-by-side. Byron expressed his displeasure during the caution.

“I felt like he ran me out of race track off of (Turn) 2 and had really hard contact with the wall,” Byron said. “Felt like the toe link was definitely bent, luckily not fully broken. We were able to continue.

“A lot of times that kind of damage is going to ruin your race, especially that hard. I totally understand running somebody close and making a little bit of contact, but that was pretty massive.”

On the retaliatory hit, Byron said: “I didn’t mean to spin him out. That definitely wasn’t what I intended to do. I meant to bump him a little bit and show my displeasure and unfortunately, it happened the way it did. Obviously, when he was spinning out, I was like ‘I didn’t mean to do this,’ but I was definitely frustrated.”

Drivers for Drive for Diversity combine revealed


The 13 drivers who will participate in the Advance Auto Part Drive for Diversity Combine were revealed Thursday and range in age from 13-19.

The NASCAR Drive for Diversity Development Program was created in 2004 to develop and train ethnically diverse and female drivers both on and off the track. Cup drivers Bubba Wallace, Daniel Suarez and Kyle Larson came through the program.

The 2020 and 2021 combines were canceled due to the impact of COVID-19.

“We are thrilled that we are in a position to return to an in-person evaluation for this year’s Advance Auto Parts Drive for Diversity Combine,” Rev Racing CEO Max Seigel said in a statement. “We are energized by the high-level of participating athletes and look forward to building the best driver class for 2023. As an organization, we have never been more positioned for success and future growth.”

The youngest drivers are Quinn Davis and Nathan Lyons, who are both 13 years old.

The group includes 17-year-old Andrés Pérez de Lara, who finished seventh in his ARCA Menards Series debut in the Sept. 15 race at Bristol Motor Speedway.

Also among those invited to the combine is 15-year old Katie Hettinger, who will make her ARCA Menards Series West debut Oct.. 14 at the Las Vegas Bullring. She’s also scheduled to compete in the ARCA West season finale Nov. 4 at Phoenix Raceway.




Age Hometown
Justin Campbell 17 Griffin, Georgia
Quinn Davis 13 Sparta, Tennessee
Eloy Sebastián

López Falcón

17 Mexico City, Mexico
Katie Hettinger 15 Dryden, MI
Caleb Johnson 15 Denver, CO
Nathan Lyons 13 Concord, NC
Andrés Pérez de Lara 17 Mexico City, Mexico
Jaiden Reyna 16 Cornelius, NC
Jordon Riddick 17 Sellersburg, IN
Paige Rogers 19 New Haven, IN
Lavar Scott 19 Carney’s Point, NJ
Regina Sirvent 19 Mexico City, Mexico
Lucas Vera 15 Charlotte, NC


Dr. Diandra: Crashes: Causes and complications


Two drivers have missed races this year after hard rear-end crashes. Kurt Busch has been out since an incident in qualifying at Pocono in July. Alex Bowman backed hard into a wall at Texas and will miss Sunday’s race at the Charlotte Roval (2 p.m. ET, NBC).

Other drivers have noted that the hits they’ve taken in the Next Gen car are among the hardest they’ve felt in a Cup car.

“When I crashed it (at Auto Club Speedway in practice), I thought the car was destroyed, and it barely backed the bumper off. It just felt like somebody hit you with a hammer,” Kevin Harvick told NBC Sports.

The three most crucial parameters in determining the severity of a crash are:

  • How much kinetic energy the car carries
  • How long the collision takes
  • The angle at which the car hits


The last of these factors requires trigonometry to explain properly. You can probably intuit, however, that a shallower hit is preferable to a head-on — or rear-on — hit.

A graphic show shallower (low-angle) hits and deeper (high-angle) hits
Click for a larger view

When the angle between the car and the wall is small, most of the driver’s momentum starts and remains in the direction parallel to the wall. The car experiences a small change in velocity.

The larger the angle, the larger the change in perpendicular speed and the more force experienced. NASCAR has noted that more crashes this season have had greater angles than in the past.

Busch and Bowman both had pretty large-angle hits, so we’ll skip the trig.

Energy — in pounds of TNT

A car’s kinetic energy depends on how much it weighs and how fast it’s going. But the relationship between kinetic energy and speed is not linear: It’s quadratic. That means going twice as fast gives you four times more kinetic energy.

The graph shows the kinetic energies of different kinds of race cars at different speeds. To give you an idea of how much energy we’re talking about, I expressed the kinetic energy in terms of equivalent pounds of TNT.

A vertical bar graph showing kinetic energies for different types of racecars and their energies

  • A Next Gen car going 180 mph has the same kinetic energy as is stored in almost three pounds of TNT.
  • Because IndyCars are about half the weight of NASCAR’s Next Gen car, an IndyCar has about half the kinetic energy of a Next Gen car when both travel at the same speed.
  • At 330 mph, Top Fuel drag racers carry the equivalent of six pounds of TNT in kinetic energy.

All of a car’s kinetic energy must be transformed to other types of energy when the car slows or stops. NASCAR states that more crashes are occurring at higher closing speeds, which means more kinetic energy.

Longer collisions > shorter collisions

That seems counterintuitive, doesn’t it? Who wants to be in a crash any longer than necessary?

But the longer a collision takes, the more time there is to transform kinetic energy.

A pitting car starts slowing down well below it reaches its pit box. The car’s kinetic energy is transformed into heat energy (brakes and rotors warming), light energy (glowing rotors), and even sound energy (tires squealing).

The same amount of kinetic energy must be transformed in a collision — but much faster. In addition to heat, light and sound, energy is transformed via the car spinning and parts deforming or breaking. (This video about Michael McDowell’s 2008 Texas qualifying crash goes into more detail.)

The force a collision produces depends on how long the car takes to stop. Compare the force from your seat belt when you slow down at a stop sign to what you feel if you have to suddenly slam on the brakes.

To give you an idea of how fast collisions can be, the initial wall impact in the crash that killed Dale Earnhardt Sr. lasted only eight-hundredths (0.08) of a second.

SAFER barriers use a car’s kinetic energy to move a heavy steel wall and crush pieces of energy-absorbing foam. That extracts energy from the car, plus the barrier extends the collision time.

The disadvantage is that a car with lower kinetic energy won’t move the barrier. Then it’s just like running into a solid wall.

That’s the same problem the Next Gen car seems to have.

Chassis stiffness: A Goldilocks problem

The Next Gen chassis is a five-piece, bolt-together car skeleton, as shown below.

A graphic showing the five parts of the Next Gen chassis.
Graphic courtesy of NASCAR. Click to enlarge.
The foam surrounding the outside of the rear bumper
The purple is energy-absorbing foam. Graphic courtesy of NASCAR. Click for a larger view.

That graphic doesn’t show another important safety feature: the energy absorbing foam that covers the outside of the bumpers. It’s purple in the next diagram.

All cars are designed so that the strongest part of the car surrounds the occupants. Race cars are no different.

The center section of the Next Gen chassis is made from stout steel tubing and sheet metal. Components become progressively weaker as you move away from the cockpit. The bumper, for example, is made of aluminum alloy rather than steel. The goal is transforming all the kinetic energy before it reaches the driver.

Because the Next Gen car issues are with rear impacts, I’ve expanded and highlighted the last two pieces of the chassis.

The rear clip and bumper, with the fuel cell and struts shaded

The bumper and the rear clip don’t break easily enough. The rear ends of Gen-6 cars were much more damaged than the Next Gen car after similar impacts.

If your initial thought is “Just weaken the struts,” you’ve got good instincts. However, there are two challenges.

I highlighted the first one in red: the fuel cell. About the only thing worse than a hard collision is a hard collision and a fire.

The other challenge is that a chassis is a holistic structure: It’s not like each piece does one thing independent of all the other pieces. Changing one element to help soften rear collisions might make other types of collisions harder.

Chassis are so complex that engineers must use finite-element-analysis computer programs to predict their behavior. These programs are analogous to (and just as complicated as) the computational fluid dynamics programs aerodynamicists use.

Progress takes time

An under-discussed complication was noted by John Patalak, managing director of safety engineering for NASCAR. He told NBC Sports’ Dustin Long in July that he was surprised by the rear-end crash stiffness.

The Next Gen car’s crash data looked similar to that from the Gen-6 car, but the data didn’t match the drivers’ experiences. Before addressing the car, his team had to understand the disparity in the two sets of data.

They performed a real-world crash test on a new configuration Wednesday. These tests are complex and expensive: You don’t do them until you’re pretty confident what you’ve changed will make a significant difference.

But even if the test goes exactly as predicted, they aren’t done.

Safety is a moving target.

And always will be.

NASCAR weekend schedule for Charlotte Motor Speedway Roval


NASCAR Cup Series drivers race on the road for the final time this season Sunday, as the Charlotte Motor Speedway Roval course ends the playoffs’ Round of 12.

The 17-turn, 2.28-mile course incorporating the CMS oval and infield will determine the eight drivers who will advance to the next round of the playoffs. Chase Elliott won last Sunday at Talladega Superspeedway and is the only driver who has qualified for a spot in the Round of 8.

Entering Sunday’s race, Austin Cindric, William Byron, Christopher Bell and Alex Bowman are below the playoff cutline. Bowman will not qualify for the next round because he is sidelined by concussion-like symptoms.

The race (2 p.m ET) will be broadcast by NBC.

Charlotte Motor Speedway Roval (Cup and Xfinity)

Weekend weather

Friday: Sunny. High of 81 with a 6% chance of rain.

Saturday: Mixed clouds and sun. High of 67 with a 3% chance of rain.

Sunday: Sunny. High of 68 with a 3% chance of rain.

Friday, Oct. 7

(All times Eastern)

Garage open

  • 12 – 5 p.m. — Xfinity Series

Saturday, Oct. 8

Garage open

  • 7 a.m. – 2:30 p.m. — Cup Series
  • 8:30 a.m. — Xfinity Series

Track activity

  • 10 – 10:30 a.m. — Xfinity practice (NBC Sports App)
  • 10:30 – 11:30 a.m. — Xfinity qualifying (NBC Sports App)
  • 12 – 1 p.m. — Cup practice (NBC Sports App, USA Network coverage begins at 12:30 p.m.)
  • 1 – 2 p.m. — Cup qualifying (USA Network, NBC Sports App)
  • 3 p.m. — Xfinity race (67 laps, 155.44 miles; NBC, Peacock, Performance Racing Network, SiriusXM NASCAR Radio)

Sunday, Oct. 9

Garage open

  • 11 a.m. — Cup Series

Track activity

  • 2 p.m. — Cup race (109 laps, 252.88 miles; NBC, Performance Racing Network, SiriusXM NASCAR Radio)