What determines the winner of a race? Is it the car or the driver who is to blame?

Fans frequently ask me this issue, and as we approach the All-Star Race — and evaluate who our sport’s finest drivers are — it seems like a good moment to tackle it. I’m excited to share my opinions with you, and I’m even more excited to start a conversation about it with other drivers, journalists, and fans and hear what you have to say.

THE VEHICLE

The cars have changed so much in the six years that I’ve raced in the Sprint Cup.

It used to be that driving a stock car on its own was somewhat tough. The vehicle would spin out a lot or move somewhat sideways due to this. The car would also significantly damage the tires, and worn tires cause the car to slide about a lot. A stock automobile, in general, can be a challenge. When the cars got into traffic, though, they mainly drove the same way they would on their own, so there wasn’t much of a change.

That has altered dramatically in the last decade or so. Cars have gained a lot of speed thanks to technological and aerodynamic advancements — for example, computational fluid dynamics. They’ve also gotten a lot easier to drive along the road. As a result, the tires no longer fall off as frequently. The automobile isn’t swaying nearly as much. When a car gets a little loose, it’s extremely easy to get it back on track.

However, cars are incredibly difficult to drive in traffic. They don’t seem to be able to recuperate quickly. They’ve lost a lot of control. They move around quite a bit. They’re unpredictably unpredictable. The aero wake created by an automobile is significantly greater than it used to be, especially when you’re following closely behind another vehicle. Imagine you’re behind a tractor-trailer instead of another car on the freeway in traffic. The aero wake has expanded to that size. You’d notice how much your vehicle moved all around if you got close behind that tractor-trailer or pulled up behind it on the freeway. You’d have a sense of being out of control.

Multiply that sensation by three because you’re going 180 or 200 mph on the racetrack instead of 60, and you’ll have a sense of how it feels.

As a result, what it means to be a race car driver has changed dramatically. Most drivers will tell you that driving a stock car alone has never been easier than it was now in 2015. Then they’d say that driving a stock automobile in traffic has never been more difficult than it is now in 2015.

That is to say, a driver who is in the lead and pulling away from the pack has a fantastic vehicle. Leading by yourself isn’t always so amazing. It also doesn’t rule out the possibility that a driver with a large advantage is the best driver.

THE DRIVER

A top-five car must win a Sprint Cup race, except for changeable races such as restrictor plate or fuel usage races. That’s something you already know before the racing weekend begins. It may be the first-place automobile. It may be the automobile in fifth place. However, a car with top-five speed will win, and the reason is simple: a driver’s inability to overcome not having a top-five car is too great. You won’t win a non-variable Sprint Cup race without a top-five rate.

We used to judge a good driver based on his ability to lead laps and dominantly win races. Loop data, which NASCAR accumulates — similar to a quarterback rating — to try to tell you who the top drivers are, has its origins in this. When you’re leading by yourself or qualifying in 2015, the cars perform most of the work, making loop data less valuable. As I previously stated, the most skilled driver isn’t always the one that goes the fastest in the clear.