Occassional thoughts about orienteering

Wednesday, August 31, 2011

Another look at the toughest leg


I spent some more time looking at the GPS tracks for the section of the WOC women's middle distance final that I wrote about yesterday. But before I got to the 14th leg, I noticed a couple of runners taking a trail route on the 12th leg. Most of the runners followed the line straight to the control. But, two of them dropped down to the trail, then came back up to the control. In the first map clip you see the "live" GPS track for Dana Brozkova and Lizzie Ingham. They were together at the point shown in the map below.

Brozkova dropped down to the trail and then came back up to the control, adding a bit of distance but also spending some time running along a trail. They were back together at the control. I think it is fair to conclude that Brozkova's trail route is essentially equivalent to the straight route.

The other runner who took the trail approach to 12 was Annika Billstam.

Now, on to the 14th leg. The toughest leg on the course.

I think the leg is tough for a bunch of reasons. It is near the end of the course. That means the runners are tired. It also means you might start thinking the course is over and let your concentration wander. There is enough green on the leg that it may be a bit rough to run through the forest. That said, it doesn't look all that difficult. You could run to the highest point on the map clip and you'd be just a bit outside the ring. If you don't want to climb up to the top, it looks like the reentrant just before the control should be a feature you could find.

I was inspired by Brozkova's and Billstam's routes to look at the trail option. The map below shows the two options that caught my eye. It looks like a lot of extra distance. The trail option doesn't look to give you an especially good route to the control. None of the runners took that option, so it is a difficult to tell how much time it would have taken.

If you knew in advance that this was the toughest leg on the course - a leg where almost 20 percent of a group of the best orienteers in the world would struggle - maybe you'd give the trail option some thought. The last map clip shows the routes of the 8 orienteers who had the most trouble on the leg.

Two of them ended up finding control 14 from the trail, but only after missing the control and bailing out.

One runner lost about 6 minutes on the leg (based on WinSplits Pro "time loss"). The runner who suffered the most was almost certainly Lizzie Ingham. By WinSplits Pro, she lost 2:42 on 14. On the rest of the course, she only lost another 48 seconds. Take that 2:42 off her total time and she would have 36:26 and an 8th place finish.

Back to okansas.blogspot.com.

posted by Michael | 8:13 PM


Going around to the right does not make the control much easier, so I wouldn't consider this option.

The reason for the mistakes is probably (1) that it looks easy and clear on the map, but is not that clear in the forest and (2) that it is at the end of the course. I was there myself to take a look, and if you go too far left it is easy to make a parallel mistake and think you are between the two hills when you are instead between the leftmost hill and the knoll.
Why don't people use their compasses? Just aim at the long and easily spotted depression north of the control. From there it's easy.
Jan - I agree that it doesn't make the control easy to go around on the trail. Though I don't think it makes the control harder.

LL - it is always easy when you're just looking at the map! And, of course, lots of people didn't have big time losses on this leg. Executed correctly a straight route is good.

So may be the 15th control is where it is to move runners out of the area quickly, not interfering with people doing parallel error to the left.
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