Air wrenches chirp through the walls of the high-tech garage as I ask the 18-year-old rookie to confess the dumbest thing he's ever done on the track. He grins like he's been caught shooting spitwads.

"Oh yeah, well, one time I went through the grass in the infield to make a pass," says William Byron, the points leader in the NASCAR Camping World Trucks Series.

Such a grotesque transgression of racing code would demand frontier justice at 165 mph, before any race official could black-flag the offender. The sanctions would probably compound for being a blue-eyed hotshot with a pop-idol's blonde mop of hair. But Byron avoided punishment because he didn't actually do this in real life.

He did it in iRacing, the PC driving simulator that he credits with training him to drive professionally, racking up a rookie record five victories that have made him one of stock car racing's it-boys, seemingly overnight. When the Truck Series Chase playoff begins Sept 24. at New Hampshire Motor Speedway, Byron, who graduated high school just this May, is seeded first.

Teenage experimentation

"Thankfully, I haven't had a lot of wrecks," on a real track, Byron told me in a lounge at Kyle Busch Motorsports of Mooresville, N.C. "I think I got them out of the way on iRacing, along with things like being in a bad position, like racing three-wide, or doing something stupid on a restart that could get you wrecked.

"You know, sometimes you're like, ‘Well, why won't this work?' and you try it? I already know it won't work," he says matter-of-factly.

Byron's iRacing career is a nice angle on an archetypal rookie-of-the-year story, and a great crossover with the emerging esports scene and its huge audience. Yet as practiced as his manner is with the racing press, he isn't just blowing kisses to a video game or its fanbase in hopes of growing his own. Byron's eye-popping real-life successes and his understandable failures this season align with his proficiencies in iRacing, a precise simulation several orders of magnitude above the likes of Gran Turismo or Forza Motorsport on consoles.

"Sometimes you're like, ‘Why won't this work?' I already know it won't."

"When we went to Iowa this year," where Byron led 107 of the race's 200 laps, "the race track in the game looked virtually the same as it does in real life," he said. Even his worst finish has hooks in his iRacing origins. That was July 20 at Eldora Speedway in Rossburg, Ohio — a dirt track. There's no dirt racing in iRacing, though it does have plans to add that surface by the end of the year. Byron finished 14th. He's finished in the top 5 in 43 percent of his virtual races on pavement.

Steve Myers, the executive producer of iRacing, believes his game legitimately can create professionally capable racers. Byron is proof after all. But the driving acumen it cultivates is just one of several conditions to be met if someone is really going to race professionally, much less in one of NASCAR's three national series.

"Let's be honest, it's next to impossible to do this as a professional," Myers said from iRacing's headquarters in Bedford, Mass. "It's probably unfair to say that a vast number of people have come from a pure simulation and gone into the professional world, and been successful because of that. The people who come into the professional world are the ones who have the funding, let's be honest."

This all means Byron is unique without being special, at least among his peer reference group. The two-dozen-and-some regulars on the Camping World Truck Series all got a break somewhere, too; Byron's happened to come from a video game, no less random than any other origin story.

When he won his first two races, other drivers were collegial and back-patting about it. The fifth made him a certifiable threat. "I, honestly, don't bring it up a ton with those guys, because they don't necessarily take it too seriously," Byron told me, referring to his computer simulated background. "The people I'd talk to would say, 'What have you raced?' and I'd say, "Well, I've done some iRacing,' but they had no idea what that is or what it means."

Rare is the teenager who doesn't harbor the dream of becoming a professional in their favorite sport. A racing fan that age has vastly fewer opportunities, even to discover his or her talent, than one trying to make the NBA or NFL or a major college's roster. The financial barriers to entry are profound (your essential equipment is an automobile, after all, and it gets worse from there). Stock car racing may celebrate a rural, working-class heritage but it is tremendously inaccessible, with no Little League or high school equivalent.

iRacing, however, gave Byron an opportunity to see if he really did have an aptitude worth bankrolling to five or six figures.

His first two seasons in iRacing, 2011 and 2012, he started 683 races, qualified first in 95, won 104, and finished in the top 5 in another 203. He averaged a top-10 finish right out of the box. That helped to convince his father, a wealth management advisor in Charlotte, Bank City U.S.A., that he would be worth the business risk. And it reassured his mother that he wouldn't get himself killed.

iRacing convinced William's dad he was worth the money. It convinced his mom he wouldn't get killed.

"I have a note that says I've got to pay a lot of it back," Byron says. "My dad's biggest thing was, if this is something I want to do, it's going to take investment, and you have to pay it back."

The Byrons bought into Legends racing, a low-level series whose vehicles look like Prohibition-era gangstermobiles. iRacing wasn't wrong about Byron's talent. He won the U.S. Legends' Young Lion Division in 2013, taking victories at the Atlanta and Charlotte superspeedways seen in Sprint Cup races on the TV.

"I can, within 30 seconds of seeing a person try iRacing for the first time, get an idea of whether or not he'll be good at it," said Myers, the Iracing executive. iRacing, working with the state-of-the-art, feedback driving wheels that the game requires, can deliver that slight bump at the end of pit road at Indianapolis Motor Speedway, the one that can spin out an inattentive professional in real life.

"You have to flip the switch, in your head, and sit down and approach it like you are strapping into a race car," Myers said. "This isn't Gran Turismo or Forza, with the helicopter view, and you mash buttons with infinite traction helping you get around the track. You have to approach it like a driver in real life."

In the background, Byron's father was working through a contact at Liberty University, arranging a sponsorship that has carried over to higher divisions, with higher costs to defray. Dale Earnhardt Jr's JR Motorsports signed on Byron to race late model cars in regional competition in 2014, with Liberty on the hood. It was a good fit for all. Liberty has an enormous online enrollment, Byron's racing education came from a PC, and Earnhardt is one of iRacing's most famous patrons.

"I wouldn't be surprised if he somehow connected [Byron's] success in iRacing to real life," Myers said. Byron, on the record, says iRacing gave him "a unique story to tell" to JR Motorsports. "It was something that Dale was interested in, and he liked to have people on his team that were interested in iRacing, just like he was."

JR Motorsports already had its teenage phenomenon in the Trucks series though: Cole Custer, who is actually a few months younger than Byron (and currently 11th in the standings). Of NASCAR's three national series, the trucks are the real minor league feeder. They race on weekdays more than weekends, and typically it's a money-loser for a team that participates. A Chase-for-the-Cup playoff format was introduced this year to mainstream the series with the Sprint Cup and inject some interest into its later events.

Still, the truck series has value as a testing ground for new talent, or an outlet for experienced drivers who don't have a ride in NASCAR's two higher series. It's also an opportunity for big stars in the Sprint Cup, like Busch and Brad Keselowski, to try their hand as team owners. Last season's champion, Erik Jones, raced for Kyle Busch Motorsports and moved up this year to the Xfinity Series, one rung below the Sprint Cup, with Joe Gibbs Racing. Busch races for Gibbs on the premier circuit. Byron, after winning both the K&N Pro Series East championship and the series' rookie of the year in 2015, with Liberty on the hood, took Jones' place on KBM's truck-driving staff this year.

The new hire quickly acquitted himself, snagging his first victory in his fourth start despite wrecking in the last lap of his Daytona debut, and blowing his engine for a DNF in Atlanta in his second race. After his first win in Kansas, Byron sneaked a victory at Texas Motor Speedway in a race where he led only the last six laps.

"Yeah, he's got good equipment, but look what he's doing with it. He's gone right to the front and won," one racing insider told SB Nation.

Byron struck back at Iowa the next week, then Kentucky two races later, and most recently Pocono on July 30 before the trucks went on vacation. The next event is at Bristol, Tenn., on Wednesday, a half-mile concrete gantlet with straightaways in name only.

Back at iRacing.con, Myers has no idea how many real-world professionals race in his game. He only finds out when they add to the pile of testimony for the game's fidelity. "It's cool to discover a professional driver is using it, but they could be doing it for years and we wouldn't know it," he said.

iRacing ranks its players according to an "iRating," which means that newcomers aren't pushed into races with serious drivers and wiping out the flying start for everyone. Byron's iRating is 3370 which is above average — but not, says Myers, truly elite among iRacing's best drivers, some of whom spend thousands of dollars on equipment to polish their edge. Byron says his performance has slipped in iRacing because he's had less time for it this year, and also because real-life racing doesn't translate back to simulation racing as well as vice versa. The key to a clean lap, he says, is more than just the visual information and making the right decision with it.

"When my friends race, they don't know the things I know about why the race car goes fast." Byron says. They try to do what he does in iRacing and he beats their lap times by three seconds, which is an eternity in motorsports. "It's hard to say just, ‘Hey, this is the one thing that makes me go faster.' Momentum's a big thing in the truck series, too, because trucks don't have the horsepower compared to cars.

"We just have that feel for how to go fast and how to race," Byron says.

Roster File is Polygon's column on the intersection of sports and video games.