Dr. Diandra: The potential impact of changing pit stop choreography
Richmond was our first chance to observe Joe Gibbs Racing’s new pit-stop choreography under race conditions. Let’s look at how much of an advantage this new approach offers now, and potentially in the future.
Just the facts
Three numbers made the rounds after the Richmond race:
- Kyle Busch’s team performed a four-tire-and-fuel pit stop in 9.1 seconds on Lap 234.
- Denny Hamlin’s Lap 354 pit stop took only 9.4 seconds.
- Kevin Harvick’s final stop at Lap 353 was 9.9 seconds.
JGR provided these numbers. Their measurement starts when the car stops in the pit stall and ends when the car starts moving again. That’s a standard training metric because it focuses on the pit crew’s execution.
NASCAR timing and scoring measures from when the car enters the pit box to when it leaves the pit box. Looking at the same three stops as above but using NASCAR’s numbers:
- Kyle Busch’s Lap 234 pit stop took 10.0 seconds.
- Hamlin’s Lap 354 stop was timed at 10.4 seconds.
- Harvick’s last stop was 10.7 seconds.
NASCAR’s numbers account for drivers who get into the box faster or take off slower. Although Hamlin’s stop was 0.5 seconds faster than Harvick’s (using JGR’s measurement), it was only 0.3 seconds faster when we consider getting into and out of the box.
Although Kyle Busch’s stop was heralded for its speed, NASCAR reports William Byron’s four-tire stop on lap 234 as 9.97 seconds -- three-hundredths of a second faster than Busch’s fastest stop.
Outside the box
The pit stop per se is just one component of a trip down pit road. The driver must navigate traffic (if pitting under green) and not make a commitment line violation. Once on pit road, he must keep the car as close to the pit road speed limit as possible without going over. He has to locate his pit box and get to it without hitting other cars or crew members. He has to stop at the right place in the box, angling the car as best he can for a speedy departure.
After the crew changes tires and adds fuel, the driver must exit the box without hitting other cars or crew members. He again must go as fast as possible without incurring a speeding penalty.
Both coming in and going out, the driver also has to be aware of timing lines. Depending on the location of the lines relative to the pit box, a driver can briefly go faster than pit road speed without his average speed being over the limit.
There’s a lot more to pitting than just watching a row of colored dots on the dash.
If we now include time on and off pit road for the same three stops we’ve been discussing:
- Kyle Busch’s Lap 234 total pit time was 38.6 seconds.
- Hamlin’s Lap 354 total pit time was timed at 39.05 seconds.
- Harvick’s total pit time was 39.14 seconds on his last stop.
Let’s compare the last two of these stops head to head:
Harvick was 0.24 seconds faster getting to and from his pit box relative to Hamlin on their last stops. While Hamlin’s pit crew may have been 0.5 seconds faster, the overall difference in pit times was less than a tenth of a second.
But if Hamlin’s crew hadn’t earned him an advantage, Harvick might have gotten out ahead of Hamlin. NASCAR is a sport of tenths and hundredths of seconds. Every tenth of a second gained on pit road makes the gap between the driver and the car in front of him a tenth of a second smaller. Or gives him an additional tenth of a second gap between him and the car chasing him.
What we learned in Richmond
We gained only a fleeting glimpse of the technique last weekend. With a limited number of pit stops and the combination of different pitting strategies with green-flag pit stops, it’s hard to quantify the real advantage.
“I’m a little bit disappointed everything seemed like it was green-flag stops because I think some of the pit stop speed got lost in that,” Brian Haaland, pit coach for JGR told NBC Sports’ Dustin Long after the race. “If you were under caution and they were lined up one after another, you would have seen some big-time gains on pit road.”
These stops offered a trial-by-fire for the pit crews. Rear tire changers aren’t used to jumping out in front of a pitting racecar. Yes, they’ve practiced and practiced, but pit practice drivers don’t come in as hot as Denny Hamlin or Kyle Busch during a race.
The new pit stop choreography is a little more complicated than the traditional pit stop. That means more places for things to go wrong, and more practice required for everyone involved. Bubba Wallace’s No. 23 team decided to stick with the old pit stops after its car chief was sent home. The car chief was supposed to have helped maneuver the air gun hoses behind the wall. The team didn’t feel confident subbing in someone else.
“These jobs behind the wall are just as important as what we’re doing on the other side of the wall,” Haaland noted.
That the process is more complicated may be a boon for JGR. Given that other teams will likely copy their choreography, JGR hopes that their eight months of practice will give them an advantage -- at least for a little while.
An additional tool, not a replacement
Although the new technique is faster, it can’t be used everywhere -- or even every time. NASCAR first allowed rear tire changers to move in front of the car at Atlanta, but most stops there were for two tires. COTA’s pit road was just too narrow. Richmond provided the first ‘just right’ location. At Richmond, all four JGR teams chose pit boxes with openings or unused stalls on one side.
But even at tracks where the technique is feasible, it might not be optimal in every pit stall. Martinsville’s small size requires situating some pit stalls in the turns. That can make it difficult for the crew to see the car coming in -- and vice-versa. Dale Jarrett, in the NASCAR on NBC podcast, expressed concern about pit crew safety in general under the new choreography.
Finally, if the crew chief wants to make adjustments, the pit crew will use the traditional pit stop pattern. The new choreography is not a superior way to do pit stops. It is an alternative approach that potentially offers an advantage in some cases.
Pit stops depend on many factors. It’s rare for a team to get all of them perfect on a single stop. Teams try to save as much time as possible so that, when it really matters, they can be as close to perfect as possible.