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Tilden Regional Park

Date: (Sun.) Jan. 24, 2010
Location: Berkeley, CA
Event Director:
Course Setter: Jonas Kjall
Type: B; We had some nice courses from Jonas in the north end of Briones this past Spring. Let's see what he can do in Tilden!


Course Setter's Comments

By Jonas Kjall

Variation is very important in setting a good long-distance advanced orienteering course. I tried to put on several legs with interesting route choices in Tilden, and I will comment on most of them below for the Blue course (most of the route choices on the other advanced courses were the same or similar).

Let me first say a few words about route choices in general, for those who are not so experienced (for more in depth, see for example Martin Kunz's Course Setter's Comments from the last B-meet in Tilden). Four important things to consider when choosing a route are:

  1. Distance – How far will I run with this route?
  2. Climb – How many meters will I climb? How steep is the climb (can I run, or do I have to walk)?
  3. Runnability – Is most of my route on trails, open land, in forest, dense forest, etc. Is it flat or am I contouring? If there is a downhill part, can I take full advantage of it, or is it so steep that I have to "brake"?
  4. Navigation – Is there an enhanced risk for me to lose time by making a mistake? How easy is it to navigate along my route? Is there a good attack point?

Since a course consists of more than one leg, there are also the future aspects of a route choice. Can I waste less energy on a route choice? Is one less mentally demanding so I can plan ahead and study the rest of the course.

As you can see, choosing a good route is very complex and also individual (depending on your strengths and weaknesses), so it is hard to give good advice, most of it is probably done by experience. In general it is good to find the shortest route and then see if you can find a faster one. In the Bay Area it is probably best to start to look for the route with least climb and then see if you can find a better one. Normally I also try to pick a route choice with a lot of trail running in the beginning of the course (even if I lose a little bit of time) to be able to read the map ahead, get an overview of the course, and decide which route choices to take at later parts of course (while I am still fresh and can think clearly).

Now for some specific comments about this year's Tilden event.

I test ran the Blue course twice (had planned to do it a third time), and got splits for most of the legs (forgot to "save" a few). For the splits I have, I will give the extra time the slower of those took for me (running at 10 min/km and executing well [because I had visited all sites before]). Which route choice is best is of course individual, but my comparison should hopefully work fairly well, especially for an experienced orienteer (for example if you run at 15 min/km, multiply the time difference by 1.5). I have drawn routes in RouteGadget (http://baoc.org/gadget/cgi/reitti.cgi?act=map&id=205&kieli=) for Course Setter 1, 2, and 3. CS 1 should (hopefully) refer to the fastest route, and CS 3 to the slowest. I recommend that you take a look at the Blue course (you can see it on RouteGadget (http://baoc.org/gadget/cgi/reitti.cgi?act=map&id=205&kieli=)), and decide which route choices you think are best before you continue reading and check my routes on RouteGadget (http://baoc.org/gadget/cgi/reitti.cgi?act=map&id=205&kieli=).

51–57: Blue 1–2

Slightly left vs. left, +56s. Slightly left has minimum climb (and best runnability of those sub-route choices) and not to much extra distance.

58–61: Blue 3–4

Left. Both have the same climb, left is a bit shorter, but the rough open has slightly worse runnability then the trail where also the downhill comes more gradually. However the dark green is very slow and should be avoided at all cost. Some told me they found a decent way out of it, but it should still be much slower.

61–65: Blue 4–5, Green 3–4

Straight vs. left, +69s. Straight is shortest, has less climb, and the runnability is not so much worse. The power-line bend makes a good attack point regardless of route choice.

65–64: Blue 5–6, Green 4–5

Left vs. right, +28s. Left has less climb, is slightly shorter, and the runnability is not so much worse.

64–63: Blue 6–7, Green 5–6

Right vs. left, +121s. Right has a lot less climb, 10 m (that you take gradually) compared to 50 m for left (that you take straight on, i.e., tougher), and the terrain out from the control (left) is slow as you should have seen on the way in. However, I didn't expect the difference to be this big.

62–60: Blue 8–9, Green 7–8

Left vs. right, +33s. Right has 15 m more climb and is a bit longer.

60–54: Blue 9–10, Brown 5–6

Right vs. straight, +15s (i.e., only a small difference between these route choices). Right has 20 m more climb (but it comes very gradually and doesn't slow you down so much), you spend more time on the trail, and the downhill is not as steep (so you can take full advantage of it).

54–55: Blue 10–11, Brown 6–7, Orange 3–4

Left vs. right, +2s, negligible difference. Right is slightly shorter, but left has slightly better runnability (an indistinct trail through dark green can be expected to be slow, the rough open to the right was pretty slow as could be seen from 10). Also, left has a better attack point; the beginning of an indistinct trail that doesn't continue out in the open might be hard to find (apparently even when I put out a streamer—sorry, should have had a big sign instead).

55–70: Blue 11–12, Red 6–7

Straight is much closer and only 5m extra climb. The downhill is so steep that it is (almost) as fast in the forest with undergrowth as on the trail.

70–74: Blue 12–13, Red 7–8

Straight vs. right, +36s. Straight is closer and no extra climb.

74–79: Blue 13–14

Straight vs. right, +25s. Straight is closer but slightly more climb. Going at more than 90-degree angle (to/from a control) makes the distance longer then it looks.

49–47: Blue 14–15, Red 9–10

Right is fastest (I think). The medium dark green is slow, especially when you also are contouring on a steep slope. Left is most climb, but best attack point.

48–46: Blue 16–17, Red 11–12

Right is fastest (I think), not so much longer (it is a short leg), and you avoid the green.

46–42: Blue 17–18, Red 12–13

Right vs. straight, +6s, negligible difference. Straight is shorter, but 35 m extra climb.