# Road running rule: straight line distance **URL:** \ **Category:** The Game Room\ **Created:** [October 9, 2023, 5:18pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323 "2023-10-09T17:18:12Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [October 9, 2023, 5:18pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/1 "2023-10-09T17:18:12Z")
I was looking at the [Book of Rules](https://worldathletics.org/download/download?filename=7be8b411-2fca-4841-a5fe-9c8db836cc27.pdf&urlslug=C1.1%20%26%20C2.1%20-%20Competition%20Rules%20%26%20Technical%20Rules) for athletic competitions published by World Athletics. In the section for road running events, rule 31.21.2 says > The start and finish points of a course, measured along a theoretical straight line between > them, shall not be further apart than 50% of the race distance. So, for example, a completely straight course is prohibited. What is the point of this? What difference does it make what the straight line distance is between the start and finish? ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 9, 2023, 5:20pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/2 "2023-10-09T17:20:29Z")
> [@markn\_1](#): > > So, for example, a completely straight course is prohibited. What is the point of this? To reduce the likelihood of a tailwind for the entire course. Although I’m not sure why it would matter except for the validity of any record. Perhaps because some athletes are better than others in tailwind/headwind, so aside from the validity of any record, it would favor some athletes to have a constant headwind or constant tailwind? Other things being equal, more heavily built runners will be better in a headwind. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [October 9, 2023, 5:22pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/3 "2023-10-09T17:22:34Z")
> [@markn\_1](#): > > I was looking at the [Book of Rules](https://worldathletics.org/download/download?filename=7be8b411-2fca-4841-a5fe-9c8db836cc27.pdf&urlslug=C1.1%20%26%20C2.1%20-%20Competition%20Rules%20%26%20Technical%20Rules) for athletic competitions published by World Athletics. In the section for road running events, rule 31.21.2 says > > > The start and finish points of a course, measured along a theoretical straight line between > > them, shall not be further apart than 50% of the race distance. > > So, for example, a completely straight course is prohibited. What is the point of this? What difference does it make what the straight line distance is between the start and finish? You can have a perfectly straight course. However, it will _not_ be eligible for possible world records. The idea is to cancel out a downhill and/or tailwind assisted time. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [October 9, 2023, 5:41pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/4 "2023-10-09T17:41:20Z")
Ah, I never thought about a tailwind. Thanks, ignorance fought! ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [October 9, 2023, 7:17pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/5 "2023-10-09T19:17:29Z")
> [@markn\_1](#): > > Ah, I never thought about a tailwind. I think it’s more for elevation loss than tailwinds, but both are valid factors. For example, the Boston Marathon, being a point to point course and dropping 3.3 meters per kilometer, is not certified for any world records. > **[Why a world record set in the Boston Marathon wouldn’t officially count](https://www.boston.com/sports/boston-marathon/2021/09/28/why-world-record-set-in-the-boston-marathon-wouldnt-officially-count/)** > > Here's why a world record set in the Boston Marathon wouldn’t officially count. There are two factors in the IAAF rules. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [October 9, 2023, 7:21pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/6 "2023-10-09T19:21:59Z")
There’s a separate rule for elevation: > 31.21.3 The overall decrease in elevation between the start and finish shall not exceed 1:1000, i.e. 1m per km (0.1%). ---
**Author:** ![RTFirefly](https://avatars.discourse-cdn.com/v4/letter/r/c77e96/32.png) [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)\ **Post date:** [October 10, 2023, 12:17pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/7 "2023-10-10T12:17:07Z")
> [@markn\_1](#): > > I was looking at the [Book of Rules](https://worldathletics.org/download/download?filename=7be8b411-2fca-4841-a5fe-9c8db836cc27.pdf&urlslug=C1.1%20%26%20C2.1%20-%20Competition%20Rules%20%26%20Technical%20Rules) for athletic competitions published by World Athletics. In the section for road running events, rule 31.21.2 says > > > The start and finish points of a course, measured along a theoretical straight line between > > them, shall not be further apart than 50% of the race distance. > > So, for example, a completely straight course is prohibited. What is the point of this? What difference does it make what the straight line distance is between the start and finish The link won’t open for me, but I assume there’s an exception for extremely short races like 100m. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [October 10, 2023, 12:36pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/8 "2023-10-10T12:36:09Z")
> [@RTFirefly](#): > > The link won’t open for me, but I assume there’s an exception for extremely short races like 100m. These rules are for road races. Track races are required to have a certified wind gauge for record consideration. 2.0m/s and over disqualify a record. Straight line events only (100, 200, triple/long jump, 100/110 hurdles) ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [October 10, 2023, 12:44pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/9 "2023-10-10T12:44:52Z")
> [@running\_coach](#): > > These rules are for road races. So are races like the [Fifth Avenue Mile](https://en.wikipedia.org/wiki/Fifth_Avenue_Mile) not eligable for any records? ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [October 10, 2023, 1:04pm UTC](https://boards.straightdope.com/t/road-running-rule-straight-line-distance/991323/10 "2023-10-10T13:04:11Z")
It’s a road race so it has to meet the start/finish line separation requirements.