In many track races, competitors will not line up at one even starting mark. Instead, runners start in their own lane at different positions on the track. This creates a staggered appearance for the runners when viewed from overhead. The goal is to ensure that each runner covers an equal distance instead of forcing the outside runners to travel farther to reach the finish line.
Most standard track events start with each runner in a staggered position in his own lane. The runner must remain in his lane for the entirety of the race. The starting position for the innermost runner will usually be set on the finish line. Each runner from there out will start slightly farther forward along the track. The result is that each competitor runs a slightly larger loop than the one to his left, but still runs exactly the same distance.
The 100-meter sprint event is an exception to the typical staggered setup. It is run on a straightaway track stretch. Therefore, all runners start in a straight line, next to one another. Also, in some longer events, such as the 800 meters, runners start in a normal staggered formation, but are then allowed to leave their lane after a set distance.
Competitors in cross-country follow different rules than those that apply to competitors in shorter events. Generally, cross-country runners begin the race on a straight starting line because the start has a significantly smaller effect on the results of a long race than they do on the results of a short race. In short races, finishers can sometimes be separated by only hundredths of a second.
Rules for events run in the Olympic Games and certain other major events can vary from rules for smaller events. For example, competitors will sometimes be split into two groups of four. One group draws for spots in the inner four lanes, while the other group draws for spots in the outer four lanes. Also, unlike most other major events, the Olympics uses a traditional starters gun. This type of starting gun can give inside runners a fraction of a second advantage at the start, according to ABC News.