Halfway through the 2021 NASCAR playoffs, 12 challengers remain eligible for the championship. But entering today’s Bank of America Roval 400 (2 p.m. ET, NBC), drivers and teams are separated by the magnitude of their statistical strengths.

Let’s take a look at the best and worst of the playoffs in major stat categories:

Most efficient passer: Guillaume Byron

Byron was on the verge of elimination in the first round of playoffs and may need a win over Charlotte’s Roval today to enter the Round of 8. But those notions mask what has been a solid individual effort. in the playoffs, one suggesting an improvement in his long-term passing acumen on a small sample size.

No driver has a higher excess pass value * during the playoffs than Byron’s + 5.03% mark, from which he had a combined 68-position pass differential better than an expectation statistic defined by its average running position.

Given that his average back and forth in four of the five playoff races was comparable to his regular season average, this is a significant jump from his regular season effort. His SPV after the first 26 races finished in the red at -0.15%, the worst among the four Hendrick Motorsports drivers.

* The overshoot value measures the difference between a driver’s adjusted passing efficiency and the expected APE of a driver with the same average stroke position, based on a field-wide slope .

Least efficient passer: Kevin harvic

Harvick is emerging as the least efficient long-term driver among the remaining drivers in the playoffs. His SPV of -4.81% gave a combined pass differential of 49 positions worse than his statistical expectations and no run with a positive differential.

Through green flag pit cycles, team manager Rodney Childers secured 16 track spots in Richmond and Las Vegas, completing his driver’s long runs enough to place in the top 10 in both races. .

The story continues

Best full reboots: Martin Truex Jr. and Denny hamlin

The two Joe Gibbs Racing drivers organized short masterclasses during these qualifiers.

Truex’s 76% retention rate within the first seven rows paces all drivers. He’s one of three pilots with a 100% perfect rate when restarting from the preferred groove in particular. He had 1.64 positions per restart, the second-best average among playoff drivers.

Hamlin, meanwhile, cushioned typical position losses on non-favorite groove reboots better than any of his playoff contenders. Out of 11 of those attempts, he lost just four positions, which benefited his best net win of 17 in the playoffs. Its retention rate of 75.86% ranks second, behind Truex.

Worst general raiser: Kevin Harvick

In addition to his poor performance on long runs, Harvick’s short runs – that is, two-lap windows after each start or restart – hamper his progress in position.

His 53.33% position retention rate is the worst among drivers in the playoffs, as is his 9.09% retention rate of the un-preferred groove in particular.

Fortunately, he seems to be aware of this shortcoming; out of 30 choice rule attempts, he chose to start over from the preferred groove 19 times. Relying on the strength of each track’s strongest groove allowed it to minimize a net position loss (-5 points) that one would expect to be greater given the relative tossup provided by its rate. retention.

Fastest Team: Denny Hamlin, Joe Gibbs Racing

Hamlin’s Toyota Camry, the fastest car in the playoffs, placed the fastest (based on its mid-lap ranking) in Richmond and Las Vegas, while its fastest lap in each of the top five playoff races placed in the top four of each driver’s fastest lap.

It’s a slightly surprising development but not unexpected. His car placed second overall in the regular season and the fastest on the 750 horsepower ovals in particular. This first round of playoff races saw three 750-horsepower tracks – the key to its success during the race – but producing the fastest car at the 1.5-mile Las Vegas Motor Speedway was a new ride that changes the results. for 2021 compared to this No. 11 team.

Hamlin’s fastest outings on 550-horsepower tracks during the regular season were in Kansas and Michigan, races in which his median lap time placed third.

Slowest team: Alex Bowman, Hendrick Motorsports

It’s a forgettable playoffs so far for Bowman, in part because he and his team have yet to reach the top five in speed on any track, a feat they have achieved in five of the 26 regular season competitions. .

Speed-based playoff success was likely to prove difficult for Bowman. He entered the playoffs 10th in median lap time on 550-horsepower tracks and 11th on 750-horsepower ovals, facing a schedule made up mostly of his slowest track type.

His fastest car from the playoffs arrived last weekend in Talladega. His halfway lap placed eighth in the race and fourth among the playoff drivers, but didn’t manifest itself in a point windfall or a good result. A fall on lap 99 relegated him to 38th place. He sits 52 points below the limit, needing a win today at Roval to advance to the round of 16.

Biggest Speed ​​Improvement: Kevin Harvick, Stewart-Haas Racing

Harvick’s playoff survival at this point and his potential advancement – he’s nine points below the threshold heading into today’s race – is testament to a team effort, a year-round recovery after a struggle at the start of the season. At the end of the regular season, his No.4 team placed 11th in average lap time, sixth on the 750-horsepower ovals specifically, and 11th on the 550-horsepower non-drafting tracks.

In the playoffs, they are third overall, with his best single-race speed of the entire season at Bristol, where he had the second fastest car and led 71 laps en route to second place. But his 13th-ranked mid-lap time in Las Vegas could be a sign of things to come in a penultimate round consisting of two similar tracks in Texas and Kansas, if he gets past the round of 12.

Despite the pilot’s weaknesses and what his team’s speed could offer him over the next three weeks, it was a better and more productive playoff appearance than Harvick or Childers team leader probably anticipated at its start.

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Playoff Analysis: Most efficient assistants, best raiseers and fastest teams originally appeared on NBCSports.com