Occassional thoughts about orienteering

Wednesday, September 04, 2002

Route choice in the USA


While I was cycling today, I was also thinking about route choice. In general, I don't thinkroute choice is very important in the USA. I don't think many races are decided by route choice. Here are five reasons why:

Legs tend to be short. In the US, we tend to have courses with a lot of controls and relatively short legs. I've done some comparisons between course setting in Sweden and the U.S. and found that we don't have many long legs. When the legs are short, it is less likely that a route choice mistake will cost much time.

Course setters seem to try to make route options even. I'm not sure of this, but my general impression is that a lot of course setters think a good route choice leg is one where there are two or more options that are all similar. But, if the options are similar, the choice doesn't matter. A good route choice leg gives you options that are clearly different. For example, a good route choice leg would have an option that is clearly faster but forces you to climb; and another option that is clearly slower but is flat so you can save energy for later on the course. I don't see that sort of leg very often.

We usually orienteer in park land. Most US O' races are in parks -- land that is owned by the public and closed to forestry. Compared to land that is actively subject to forestry, parks have relatively little variation in vegetation and a simple trail network. Land where forests are harvested are full of different thicknesses of vegetation (felled areas, areas with young trees, mature forest, etc.) and the industrial processes leave a lot of trails. It is easier to have difficult and interesting route choices in forests that are being logged.

Booms are big. Booms are common and big. It isn't unusual to boom 3-4 minutes on a control. It isn't unusual to have two or three booms on a course. But, it is hard to make a route choice decision that is so bad it costs 3-4 minutes. You can often get a good result by avoiding booms and not worrying about route choice. [Note that this is something you could probably study, by looking at split times and routes. I haven't done it, but if I get inspired some day I might.]

Maybe Americans don't like route choice. I don't have any evidence, but I think most American orienteers would rather have a course with lot of controls that are hard to find than interesting route choices. A course setter who had a couple of controls that were easy to find would probably be criticized even if the legs were interesting. We tend to focus on controls rather than legs. As an experiment, take a look at a few courses and see if you could create some interesting routes by just removing a control or two.

posted by Michael | 7:46 PM


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