Freitag, 8. April 2016

Unplaned experiment on competitor steering on 2nd Swiss national competition 2016

In the aftermath of last weekends 2nd Swiss national competition it turned out that the organizer renounced to overprint all of the out-of-bound areas which they agreed with the local authorities.  Some were left undisplayed because the course-setters thought these areas would be avoided by common sense and because they only would make the map less readable (destroying the big picture, important in this type of terrain).

Once the local hunting party found that out, the press was concerned ...

The whole case reminded me of a project I collaborated  some years ago where we were sitting hidden in the forest and peeked for orienteering competitors willingly and unwillingly crossing into marked as unmarked OOB  areas. (For the records: we did not see any willingly crossings but many unwillingly crossings).

How well did it go last weekend?  - I ran a script by Jarkko Ryyppö on the route choices drawn in RouteGadget. The script basically assumes that the route choices drawn by the runners of one class represent the class as whole and in equal shares. ( 5 route choices drawn in a class with 30 competitors each get to represent 6 runners). Obviously, the more route choices you got the more representative the result turns out. The results shown here base on 218 route choices/17% of all competitors route choices.


fig.1. Competition map with "runner density". All OOB (on map as undisplayed) areas are marked in purple.

OOBs on the map

 fig.2. OOB on map
 fig.3. OOB on map
 fig.4. OOB on map
fig.5. OOB on map

 fig.6. OOB on map
 fig.7. OOB on map
fig.8. OOB on map.

What we can see here is a very high compliance by the participants. Except from the OOB on figure 6 where some few cut the south-western corner of the OOB (not marked in terrain.) all these areas seem to be a 100% followed. This high score likely  is also due to smart course setting (it should never gainful to cross an OOB)

Undisplayed OOBs

 fig.9. Undisplayed OOB
 fig.10. Undisplayed OOB
 fig.11. Undisplayed OOB
 fig.12. Undisplayed OOB
 fig.13.Undisplayed OOB
 fig.14. Undisplayed OOB

At the undisplayed OOB we find three uncrossed areas, fig.9, fig.12 and fig.13, which worked fine according to the course setters reasoning. fig.10 and fig.12 both show a single crossing. In case of fig.10. it looks like a GPS inaccuracy. In case of fig.12. it is just a very bad route choice.

Finally the OOB on fig.13 had a lot of crossings mostly along the track on the ridge. It turned out that this lay on the way of a possible route choice for M45 to the second control plus was more or less the only alternative to their sixth control (see fig.15; similar for M35). Also several runners of  M18 passed the ridge and one of them left the track towards south-east. Also some ME, MAL runner. In this single case there is a clear miss by the course-setting in regard of the OOB.
fig.15. M45 6th control.


The combination of course-setting and overprinting OOB areas resulted in a very high success rate in regard of keeping OOB areas free from competitors. Of course there might be a bias on the overprinted OOB as people are not to admit public that they breached the competition rules.

Even without overprint the impact on the OOB was minimal as long as they were consiered by the the course-setting team.

Observations during other competitions suggest that the rate of crossings of overprinted OOB areas is generally  low but unlikely zero. Marking the areas border does further reduce the number of violations, but will not reduce this rate to nothing.