"Dead running" method for separating runners in orienteering

Jarkko Ryyppö 2006-2010, Updated 15.2.2010

1. Introduction

2. Setting up course with dead running spreading

2.1 Course plannnig

2.2 Adding the spreading

3.3 Start times and equality

4. Advantages

5. Appendix

1. Introduction

The objective of this document is shortly describing and illustrating a new spreading method idea for orienteering, known as "dead running". It is a spreading method for individual long races with staggered (interval) start.

Motivation for developing new spreading method was the disadvantages of now commonly used spreading methods, phi-loops and butterflies. These often does not spread runners well enough and also if these are used spreading steals a big part of the course, lots of additional controls are added meaning lots of controls and of short legs. Courses will become something else than classic style route choice courses most orienteers would like to see planned for long races.

In short the idea of this method is setting short streamared section in two different places along the course. Competitors will be divided in three forkings, each forking will have to run these sections slightly differently. This will cause different delays along the course, these delays will spread packs apart. Method pays lot of attention how to make most out of these delays. All competitors will run same amount of dead running, but because all competitors will not run their dead runnings in same section lots of attention is paid here make sure the race is fair. Two methods is introduced to make sure race will be always fair even if we can't never be sure these two streamered sections are 100% equal.

2. Setting up course with dead running spreading

2.1 Course plannnig

Course setter plans as good course as he can without thinking of spreading at all. Focus on long route choice legs, use of best parts of the map and so on.

2.2 Adding the spreading

Next step is adding two spreading sites to two existing controls of the course. First after about 40% of the total distance, second about 70% of total distance.

Spreading site is 70 m string or steamered section from control, additional control with punch unit at the end of it. These two about 70m stereamered sections should be made as equal as possible (note also gequality uidelines in chapter 3.3) and set up to opposite direction from where comperitors approach the control, so it will not guide runners to control.

Using these spreading controls we make three courses: A, B and C.

A: At first spreading competitor will have to puch at additional spreading contol twice. So competitor will run out and back twice. At second spreading competitor will go straight.

B: Competitor will run out and back once at both spreading sites.

C: Competitor will go straight at first spreading, but will do two out and back runs at second spreading.

Course printing and control descriptions will be done using normal stardards and guidelines by IOF.

Course A:

Course B:

Course C:

3.3 Start times and equality

If start times are randomly assigned, these two spreadings should be done as equal as possible. Using test runs it should be possible to get the difference down to less than 3..4 seconds, most likely even more equal. Spreading couse will be randomly assigned just as start time. The possible 0-4 sec difference from spreading is insignificant comapred to the luck of getting one of the last starting spots and getting advantage of trails made by previous runners. Because both start time and spreading is randomly assigned, we can claim race is fair.

In some races start times are not randomly assigned. Start times are based on qualification race or ranking. For these cases approach is a little different. Now we make sure first spreading is not the slower one, we make it on purpose 2-3 seconds faster that the second one. This makes course A the fastest: it has fastest spreading and runner can study coming legs in advance while running the spreading. Qualification race winners (or best ranked runners if ranking is used instead of qualification race) will get last starting slots of the fastest course. Rest of the starting list is assigned as usual. This approach ensures the possible little advantage of diffrent spreading is earned by doing well in previous races/qualification and not randomly assigned. This makes the race fair. A competitor can't complain he lost because he got the slow spreading - he could have avoided that by running better in qualification race. Note the analogy of how runners get last starting slots today.

Spreading courses are assigned to runners according to the start list in order A, B, C and Last starter should have course A. Example:

1. C
2. A
3. B
4. C
5. A
6. B
46. C
47. A
48. B
49. C
50. A

Short expanation why this setup and how this will work. At first spreading site course A will case 80 sec delay, course B 40 sec delay and C 0 sec delay. Like this in 66% of cases later starter will be transferred 40 sec in time ahead compared to the previous starter, And 33% cases 80 sec behind. So, if previois starter follows alter starter he usually will leave spreading 40 sec after the person he was following. Or in 33% of cases he'll leave 80sec before, so he'll have to navigate on his own again for a while. If they meet again later, the follower's time is 80 sec worse than before the spreading. And second spreading will throw them apart again. Note, with this ABC order next starter never has more then 40 sec faster first streading then the previous starter. For example course C should never be right after course A, because that would move later starter with course C too near the previous runner with course A.

As second spreading these delays are just made even. Spreading works same way as in the first spreadinf site, but runners are now transferred to opposite directions in time compared to the first spreading.

If two competitor who would like to work together want to continue their co-operation after a spreading, or if they end up together othewise, the faster one has lost 40 seconds. If they stay together over both spreadings they have lost 80 seconds compared to a runner who navigates alone. So, even if packs gets not broken permanently this gives a single orienteer who navigates alone better chance against those who has part of the time the advantage of running together.

Every third competitor has same spreading, with 3 min start interval it makes 9 minutes, with 2 min interval 6 minures.

4. Advantages and disadvantages

Note, this chapter is mostly just estimations and some are my personal opinions or guessing as this method has not been used so far.

This spreading has several advantages over traditonal sprading methods. The most importatn is possibility to make classic style courses, no need to have so many controls and losts of short legs. The other advantage is powerfull spreading effect. Also time used for sprading is quite short. 80 seconds is only 1.4% of total time in 90 min race. It's small price to pay, often more time is used for spectator contols or finish chute.

I see sperading effect is advantage. This method spreads also competitors who are running at same pace. If butterly loops are used equally fast competitors will meet again after loops, so they will be apart only during loops. So butterfly loops would have be long to make them do their own navigation and these long loops would make it almost impossible to plan course with classic long character.

The amount of work needed to organize event with this spreading would be about equal with butterfly loop method. Streamering two 70m will take some effort, but on the other had less controls is needed, so work needed it's about equal. Both methods need printing separate maps/courses and control descriptions, so there is no difference. Later if/when this metod will be commonly know it may become acceptable in below championship evenst to print just one set of maps and control descriptions for all competitors. Spreading controls without control numbers or witn a special symbol. Competitors would be expected to read spreading from start list. This would make this method easier for organizers than using butterfly loops.

TV, gps tracking and spectating. Before first spreading and after second spreading we can compare competitors directly. Between spradings we would have to either estimate time used for first spreading (0,40 r 80 sec) or pick time used from online splits. Anyway, comparing competitors would be more straight forward than with using butterfly loops or phi-loop method. It is also possible to have dead running section(s) in competition center in front of spectators. This might have some value, but would spoilt the idea of having classic full orientering course. Having very challenging O course and using TV cameras in forest, gps tracking and big screen or live video broadcast to mobile phones would be better approach. In Finland O has been in TV enhanged with gps tracking for some years, best shows so far has been those with really challenging course with mistakes. Those "spectator friendly" courses with easy loops around event center has been quite boring to watch on TV. Bu this is just my opinion, some may see it differently.

In this method competitors would not have to navigate to any controls twice. With butterfly loops and phi loops there is controls competitors will have to take several times from different directions. So these method introduces significant amount of low key navigation to known controls. This dead running method introduces only full orienteering and short no orienteering at all section. I'd see this minimized low key orienteering as advantage.

While moving competitors back and forwards tens of seconds this method may sometimes cause some who were not together before spreading meet after the spreading. This side effect is disadvantage. Luckily the chance this to happen is lot smaller compared to spreading effect. Appendix example graphs do show this may happen, but it looks like this side effect isn't that significant. Course sections with short legs does have similar joining effect, so butterfly and phi loops may have similar side effect too. Also, sprading does not join runners by itself, competitors must have closed together by thdir own different performance before this would happen. So I'd say thats not something we could not accept.

80 sec dead running is most likely too long time / part of a middle race. Also, phi and butterfly loops with short legs suit well for middle course character. This is why this this method does may not be good for middle races. This dead method should never be used for mass start or chase start races. Moving competitors back and forwads like this method does is not fair in these race formats. So this method is just for long/classic format with staggered start.


Here is follow graphs of some recent WOC long races, sprading is added to some early control to illustrate how this spreading would have spreaded runners apart. Graphs are not continued after the first seprading because old groups would not be together any more, so graph would have been more or less guessing. Also courses may not be ahve been assigned to runners as recommended above, Last starter may not have course A. Here first starter has course A.

In these races start interval was 2 minutes.

WOC 2009
About 17 runners came in together with someone, all went out alone.

WOC 2008
18 runners came together, and only two (or four) went out.

WOC 2006
28 came in together with someone, 8 (or 10) runners went out together with someone.

These maps illustrate how this method could be implemeted to some old well known classic courses wihtout spoiling the course at all.

WOC 1993, West Point, USA. Spreading at controls 7 and 12.

Älgdrevet 1977. Spreading at controls 6 and 12.

Example map. Course setter should choose places with equally hard ground, similar vegetation and good runnability for both spreading sites.
Lets take a bit closer look at look phi/butterfly loops - methods we already use - fairness and equality in mind.

Here is example of a loop spreading, WOC 2008:

If you have at first round control numbered as 15, on your way to 16 you will see the reentrant where control 24 is located. Yo may even see the control. So at the next round you'll know the place already.

If you have at first round first control numbered as 24 you may see depression by the control #15 in advance. These two alternatives may be equally fast and it might not make much difference what alternative one gets, but the is navigational task is not the same for all competitors. Is see this case quite fair, but it is easy to see applying this spraeding in slightly different way it may became unfair.

Here is an other example, Norwegian night champs 2006.

Half of the runners took controls as numbered, half in order 5-9-10-6-7-8-11. Here some took 6/11 from control 10 first, saw how control is placed, saw marshes on the way to 7, Then after short visit back to 8 they could still remember these marshes and control placement and it might make leg 5-6 easy. The other half had to run 5-6 first without any knowledge of marshes or control placement. But on the other hand they did know it on second round, climbing up from 10, but that information may not be that useful because best and fastes route choice (steep slop sraight to control) does not go though the are they got to see during the first visit. Note also valley between 5-6. Half of the runners will have to decide how to run that part on they way from 5 to 6 and half when running the other direction (7-8). Ant the second attempts will be at opposite directions. Not same task for all ehre either. I don't see this spreading 100% fair and at least navigational tasks are not equal to everybody.

I am not trying to say phi loops and butterly loops are not fair. I am just saying they are not perfectly fair and equal because competitors does not have same navigational task. In dead running the navigaional task is the same for everybody. One might say that makes method more fair and better - this is orienteernig, navigation sport, not just terrain running race. I hope this dead running method is not rated unfair before first evaluating how fair other, methods already in use actually are and comparing this methods agaist results of these evaluations.

Dead running method - Example setup of a spreading control.

It may be worth having two punch units at the sperading control, slightly away from each other, one closer at hand for comping runners and one for those who leave. And having different internal code in these two units. Like this we may have better chances to be able to record time runners stayed at spreading even if competitor fails to get e punch (but gets Emit backup pin mark) at additional contol. And get better pin mark backup data. Third unit in the middle might be useful too, and letting runners know it is safest to avoid using same unit twice. Note, this issue/problems is exist also in butterfly and phi loops.

Request. If you think this method is worth to be tested and studied more and like to help, you can do it by testing it with your training group.

Set test course like this, witn 70-80 meter dead running section (sould take about 37..40 sec out and back):

Three runners should start together and run first section togehter, simulating pack of three runners. At first sprading one of the runners go straight, one runs one out and back and one twice. Secound time the other way round to make it equal. If you have more then tree runners, use several groups of three, about 6 min between start of each groups. Record it all with gps units and send files and runners comments to me, deadrunning gmail com. Note, it's pretty fun chase training too!

Note, this method is not intended to be used in mass start races. This mass start of three runners is for testing sperading effect only.