So what's all this business about two cars, hooked up, flying past drafting lines of 10 or 12 or more at Talladega?

Used to seem that the more cars, the faster in a line.

But Dale Earnhardt Jr. and Ryan Newman formed a breakaway duo late. Then they were run down and passed by the tag-team of Carl Edwards and Brad Keselowski to form the final duel and set up Edwards' now-notorious crash.

Sprint Cup director John Darby, chief technical officer of the series, explained the two-car phenomenon.

"As they team up like that [in pairs], they double their horsepower," Darby said this week on a NASCAR teleconference.

"But they don't necessarily double their drag that each individual car would have, so that enables them to go through the air quicker."

An unrestricted engine in 32 of the 36 points races develops more than 800 horsepower. Engines stifled by carburetor restrictor plates, in the four races at Talladega and Daytona, develop only a little more than 400 horsepower.

So what developed at Talladega was that two cars, jammed together, usually touching nose-to-tail, essentially developed 800 horsepower in a package that amounted to just a little more than one car.

Edwards and Keselowski had the best "one-car package" because they worked on the high side, which, Earnhardt said later, was more conducive to "winding out the engines" fully.

"Brad is pretty smart," Earnhardt said of his protégé. "I guess he was the first one out of anybody to figure out that was what [had to be done] to get back up to us."

Figuring out how to make one unrestricted car in a restrictor-plate race is what won the race for Keselowski.