A drag race is an acceleration contest, on a track, or dragstrip, that begins from a standing start between two vehicles over a measured distance. A drag racing event is a series of two vehicles in tournament style eliminations. The losing racer in each contest is eliminated, and the winning racers progress until one remains.
These contests are started by means of an electronic device commonly called a Starting Tree or more commonly the Christmas Tree because of its multicolored starting lights. On each side of the Tree are seven lights: two staging lights at the top of the fixture, followed in descending order by three larger amber lights, a green bulb, and a red bulb. There are two racers and two sets of lights, initiated by a button used by the app that indicates the start.
Two light beams cross the starting-line area and connect to trackside photocells, which are wired to the Starting Tree and electronic timers in the control tower. When the front tires of a vehicle break the first light beam, called the pre-stage beam, the pre-stage, the top light on the Tree, indicates that the racer is approximately seven inches from the starting line.
When the racer rolls forward into the second stage beam, the front tires are positioned exactly on the starting line and the bottom stage bulb is lit on the Tree, which indicates that the vehicle is ready to race. When both vehicles are fully staged, the starter will activate the Tree, and each racer will focus on the three large amber lights on his or her side of the Tree.
There are two types of timing sequences which are called a Pro Tree and a Sportsman Tree. Depending on the type of racing, all three large amber lights will flash simultaneously following four-tenths or five tenths of a second later by the green light, called a Pro Tree, or the three bulbs will flash consecutively five-tenths of a second apart, followed five-tenths later by the green light called a Sportsman, or full, Tree.
Bracket or Handicap racing is another form of drag racing. In a handicap or bracket starting system, timing is equalized to create fair competition in certain categories. In essence, this system enables vehicles of varying performance potentials to compete on an equal basis. The anticipated elapsed times for each vehicle are compared, and the slower of the two cars are given a handicap head start equal to the difference of the two elapsed times. By using this system, virtually any two vehicles can be paired in a competitive drag race.
Here’s how it works. If car A chooses a dial of 16.00 and car B chooses a dial of 14.50, car A will get a 1.5-second head start. If both vehicles cover the quarter-mile in exactly the predetermined elapsed time, the win will go to the driver with the best reaction time, or whoever reacts quickest to the green “go” signal on the Christmas Tree. A foul start or red-light is automatically disqualified.