Tony Stewart shifted in his seat and leaned back, looking thoughtful.
The defending NASCAR Sprint Cup Series champion had just been asked to offer his theory on the surprising lack of caution flags so far this season, and he struggled to come up with an explanation.
"I'm not sure I have the right answer," he said. "I'm sitting here theorizing with you more than anything."
Ask drivers why they're spinning and wrecking considerably less often this year and few can come up with a solid explanation.
"I don't know where the cautions have gone," Jimmie Johnson said. "I'm glad I'm not a part of them."
"I don't know the reason," Carl Edwards said.
Though the cause is uncertain, the numbers show a steep decline in caution flag periods this year. Heading into Sunday's race at Dover International Speedway, there have been 66 caution flags so far in 2012. But at the same point in 2011, there had been 106 cautions.
That amounts to a whopping 3.3 fewer cautions per race this season.
After April's race at Richmond, Stewart was asked a different version of the 'Why no cautions?' question. He responded with a tongue-lashing for the reporter who asked at the time, but thought more about it when he got home that night.
"I was like, 'Man...they didn't have any wrecks at Richmond,'" he said. "Nobody wrecked out at Richmond. That's virtually impossible at a 400-lap race."
But asked to explain why venues from short tracks to intermediate ovals had seen a decline in on-track incidents and an increase in green-flag runs, Stewart couldn't come up with an answer.
He rattled off a checklist of things that hadn't changed from last year – the splitter package, spoiler package, tires – and couldn't think of what had.
"What's changed? What's made the difference this year? I'm trying to think on your side now," he said. "... You'd about have to attribute it to (circumstances), because there's no one variable that sticks out that says, 'This leads to it.'"
After finishing second in last week's Coca-Cola 600, Denny Hamlin blamed the new points system for the drop in yellow flags. But when asked about Hamlin's theory at Dover, few drivers were willing to back him up.
"I don't know why any driver is saying that, because I don't see that," Jeff Gordon said after chuckling at Hamlin's theory.
Points racing "has been the nature of our sport forever," Johnson said, adding drivers aren't being more conservative this year than in seasons past.
So if it's not the points system, what is it? The real explanation is likely a variety of factors, some of which include:
• There are fewer caution-causing drivers. Wreck-prone racers such as Robby Gordon, Sam Hornish Jr. and Brian Vickers are not in the Sprint Cup Series this year.
• The cars are "better than they've ever been," according to Greg Biffle. "(The cars) drive stuck to the racetrack so good and recover fairly well," he said. "I just think that has a lot to do with why you don't see cautions."
• Drivers have gotten better at restarts. "When they started those double-file restarts, it felt like we were going to wreck every time there was a caution and had to have a restart," Carl Edwards said. "It was unbelievable. Now guys are getting very good at handling the race cars and not risking too much or taking huge chances."
• The "cautions breed cautions" theory hasn't been tested often. "If you don't get that first caution, you're taking away opportunities to have another one after that," Stewart said. "There's more opportunities for things to go wrong when we're all in a pile, I know that."
• Pressure from other drivers, car owners and sponsors not to wreck. "You lose a lot of respect from your peers when you make a lot of dumb mistakes and cause a lot of crashes," Dale Earnhardt Jr. said. "Guys don't do that anymore. Rides are harder to come by, so foolishness and ignorance on the racetrack is sort of a thing of the past because of that."
So do one or all of those theories explain the clean-and-green trend?
USA Today's Nate Ryan noted this week the Sprint Cup Series hasn't had a multicar wreck in 2,353 miles of Sprint Cup racing on intermediate tracks (Las Vegas, Fontana, Texas, Kansas and Charlotte) this season.
If that's the case, then perhaps drivers are simply smarter than ever about the damage a poor result can do to a team's Chase hopes early in the season.
"You're just trying, for the majority of the race, not to wreck yourself into a 30th- or 35th-place finish," Earnhardt Jr. said. "Everybody kind of goes for it at the end and runs pretty hard like we always have, but everybody's a lot more careful in regards to not being the first guy out of the race or making a mistake that ends the day pretty early for you."
Said Edwards: "We are driving the hell out of these race cars; we also are learning and understanding that you can't really plan on winning a race or championship if you are wrecking."