Marathon explained: why one runner can have two finishing times

A runner checks their result and finds two times: a “gun” time and a “net” time. They can differ even though the runner has not covered two distances. Before comparing performances or reading a ranking, you need to know where each of these clocks starts.

Two starting points for the same finish

The “gun” time, or time from the start signal, begins at the start signal set for the race in question. The net time begins when the runner crosses the start line. Both stop when the runner crosses the finish line.

Take a hypothetical example: the gun goes at 9:00 a.m., the runner crosses the start line at 9:02 and finishes at 12:32. Their gun time is 3:32; their net time is 3:30. The two minutes measure the delay between the gun and the runner crossing the start line. They say nothing about any stoppage during the race.

This difference changes how a result should be read. A higher gun time does not, on its own, mean the runner took longer between the two lines. To compare two times, you must first compare like with like.

In Chicago, the category matters

The Chicago rules distinguish professionals from other participants. In the professional race, on foot or in a wheelchair, gun time is official and net time is not used. For all other participants, net time is official.

The top places in the professional races are decided on gun time. Age-group awards, where offered, are based on net time. Two times shown for the same event therefore do not necessarily mean two ways of calculating the same award.

Reading the rule within its scope

Under World Athletics provisions on transponder timing, the official time runs from the start signal to the finish line. The time between the two lines may be provided, but is not treated as official under this framework.

That provision is not enough to explain how each category of a mass-participation race is handled. The Chicago event-specific rules set out their own categories and the times used. These scopes need to be kept apart, without turning either text into a rule that applies identically to all participants in all races.

Before reading a results table, then, look for the time label, the category and whether the result is provisional or final. To track progress, compare net with net or gun time with gun time. To find out a placing, consult the ranking published by the organiser: subtracting the start delay is not enough to produce a new ranking.