These days the competition in NASCAR is tougher than ever. “In our sport one 10th of a second makes you a hero or a zero,” says the driver of the No. 48 Lowe’s Chevy. “It takes a 10th of a second to blink your eye. But that amount of time separates the top 15 drivers on the track each lap. I have to run 500 miles and make every lap within a 10th of a second. On top of that, if I can perform a 10th of a second faster than the next guy, I’m the hero in victory lane.” This year, though, one of the biggest advantages Johnson has over his closest competitors isn’t the speed of his reflexes or the horsepower of his car; it’s the experience gleaned from his past championship runs. “Your mind plays games on you, and you worry about all these things you don’t need to,” he says. “Now I worry about the right things, instead of everything.”