Bump drafting may sound like a controversial army practice, but it's actually a controversial stock car racing practice. NASCAR veteran Kyle Perry calls it "positively, absolutely idiotic, period" [source: Borden]. Tony Stewart is equally blunt -- "Somebody else is going to die at Daytona or Talladega" -- and drivers such as Jeff Gordon have petitioned NASCAR to ban the practice [source: Bonkowski].
Other drivers see it as useful, even necessary. Bump drafting can be a way to liven up a very long race and, perhaps, improve your position in a long string of cars [source: Borden].
So what is it? You already know what drafting is -- tailgating elevated to an art form. Now imagine pulling forward just enough to kiss the bumper of the car in front of you. Bump! That's a bump draft.
Executed correctly, a bump draft nudges the front car forward, which means you get pulled along in its wake. The whole line of cars behind you could gets pulled along as well. And the front car usually has to slow down in response to the bump. (Stock car racers aren't the only ones who use this technique -- police use it to slow down fleeing vehicles in high-speed chases.)
Bumps create opportunities for drivers to pass, breaking up the monotony of a hundred-lap race. But they can also be dangerous, especially for the car being bumped. Its rear wheels lose traction -- that's why the driver has to slow down. Bumps are also more dangerous for both cars on curves, when wheel traction is lower anyway. And some younger drivers bump so aggressively that the technique has been renamed slam drafting.
A bigger danger: The bumped car can go into a spin, and the risk is higher at typical racetrack speeds. If the front car winds up sideways, there's a whole line of cars in position to hit it, and that hit is going to be more than a little nudge. With several high-profile accidents and driver deaths in the past decade, it's no wonder stock car racers and fans are so passionate about bump drafting.
What happens after the bump? You run. Read on to find out how.