Where, tractor pulling happens. Much like a truck pull. A motor sport, where the idea is to pull a weight transfer machine, called a sled, as far as possible down a dirt track. The farther down the track the more weight the sled transfers to the skid plate . This makes the sled harder to pull down the track. The more distance, the harder it is to pull it. As the vehicle pulls the sled down the track, the weight moves forward, creating more resistance for the tractor to pull against. Finally at the supreme moment of pull, the weight on the sled is directly over the front end of the sled. This causes enormous friction with the ground, which finally brings the vehicle to a halt, with the distance the vehicle has traveled measured from a point called a starting line to the point at which the front of the sled now rests. Pulling the entire length of the track is considered a full pull . When two or more competitors, in the same class, cross the 300 foot line this results in a pull-off.