Did Not Finish

In racing Did Not Finish (DNF) denotes a participant who does not finish a given race, either because of a mechanical failure, injury, or involvement in an accident. The term is used in all forms of racing, including automotive racing, horse racing,cycling,track and distance running, and skiing, among other types of racing. Athletes try very hard to avoid receiving a DNF, and many associate it with a negative stigma.

DNFs have been the subject of numerous studies that seek to figure out why DNF rates vary greatly, even within the same competitive discipline. For example, in track and field, Edouard found a 22% overall DNF rate among high level decathlon competitors but DNF rates in individual events ranging from less than 1% to over 6%.

DNFs are also not always evenly distributed across all participants. For example, a 2009 New York Times analysis of New York City Marathon results concluded that recreational competitors were more likely to finish the race rather than be classified as DNF: "Elite runners seem more inclined to drop out rather than simply complete the race, and runners visiting from abroad seem more inclined to push themselves to the finish line no matter their time." Glace et al. (2002) performed ANOVA analysis of finishers as compared to DNFs in an ultramarathon and concluded that they had statistically different nutrition and liquid intake. Holbrook et al. found physiological differences between finishers and DNFs among horses engaging in long distance races.

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