The Christmas Tree is the electronic starting system used in NHRA drag racing. It features pre-stage and stage lights that signal drivers to line up properly.

Once staged, a sequence of three amber lights counts down to the green light, signaling the start.

The goal is to react as quickly as possible without jumping early, which triggers a red light and results in disqualification.

Reaction time is the interval between the green light on the Christmas Tree and when the car leaves the starting line, measured in thousandths of a second.

A quicker reaction time gives a driver an advantage, as winning a race isn’t just about speed but also who crosses the finish line first.

Even a slightly slower car can win if the driver’s reaction time is better.

The winner is determined by who crosses the finish line first, not necessarily who has the fastest speed.

The NHRA uses elapsed time (E.T.)—the time it takes for a car to travel from the starting line to the finish line—and the driver’s reaction time to calculate the overall performance.

In close races, high-speed finish line cameras and sensors ensure an accurate result.

The purpose of a burnout in NHRA drag racing is to heat up the tires and lay down a layer of rubber on the starting surface for maximum traction.

By spinning the tires at high speed, the burnout removes debris, warms the rubber to its optimal temperature, and makes the tires sticky, helping the car grip the track better during launch.

Burnouts also ensure the tires are evenly prepared, which is critical for the extreme power and acceleration in drag racing.