This maneuver, while exhilarating in the James Bond sense, is not just for fun. The team is trying to teach the car to think for itself. Junior usually uses a model of the car's dynamics to control steering, gas, and braking. This is relatively easy when the car is moving straight ahead, but when it's sliding sideways across the pavement, the variables -- friction of the tires, texture of the pavement, grade of the roadway -- are far more diverse. That means working from a fixed model is far more difficult.