A 4×100-metre relay team has four athletes—one runner for each 100-metre leg. Each athlete carries the baton around the track and must pass it to the next runner inside a designated exchange zone.
The event combines sprinting speed with precise teamwork. A fast runner cannot compensate easily for a poor handoff, because dropping the baton or passing it outside the exchange zone can ruin the race. Teams usually arrange runners according to acceleration, curve-running ability, straight-line speed, and finishing strength.
The “4×100” name describes four legs of 100 metres, not four laps. On a standard 400-metre track, the first runner starts from staggered blocks, while later runners receive the baton while moving. A common mix-up is confusing this event with the 4×400-metre relay, which also has four runners but requires each athlete to cover one full lap.