How to kill a dragon? Day 3

Day 3 of the Dragon’s Back Race is less mountainous than the previous two stages. In distance, however, it is the longest stage of the entire race.

The entire stage

The fastest time was run by Jim Mann with 552.1 minutes.
The median time was 812.8 minutes.
Below are the histograms of the percentage spent over each leg.

By far the longest leg is the last one, where the runners spend close to 20% of the entire stage. Like for the previous two stages, I provide a scatterplot

My basic assumption that the percentage is independent of running time looks rather OK here. A quick look on the error bars for the slopes of the regression lines should confirm that.

Hmmm, not really very good. There is certainly a dependence in some of the stages, but it turns a bit in different directions. You remember that there is a correlation between the different percentages, don’t you? Even though the data don’t support my assumption, I’ll maintain it for the moment. We’ll see if a correction would be necessary at some point. Part of the explanation for the last leg is that slower runners get to run that (partly) in the dark, which obviously will slow them down.

Just as for stages 1 and 2, I made a set of boxplots. This is mine.

You see clearly where I had bad patches and made stupid mistakes. Again, they are for all runners available in a zip file.

Leg 1

The fastest time was run by Jasmin Paris with 64.7 minutes.
The median time was 88.6 minutes.
During this stage the runners climb Gau Graig. The general line is clear, but there is no path, so the details change a lot. Firstly, you should find the way up the mountain. Some runners clearly made a bad turn. One even managed to find an alternative route leaving the village.

The red ones (5 runners) are those that did an out and back or went over the alternative line through the village.

We clearly see that following a red line is not exactly helpfull, without being desastrous.

Once in access land, runners took multiple distinct lines. I tried to distinguish a bit.

The red ones (six runners) are those that went rather far east. Then we have a central group shown in yellow (42 runners). Finally, some went rather to the west (22 runners). Afterwards the lines join and split again, but we’ll consider that later.

Red is again not very interesting, but between yellow and green there is no real difference. Don’t worry too much and just keep the correct general direction.

I’ll try if I can make more distinctions by the way to approach the summit.

There are basically two popular lines. In the eastern line (red) there are 54 runners, while 16 went a bit more to the west (yellow).

Again, it doesn’t matter at all. It is just remarkable to see that that the faster runners opt for the more direct yellow line, while slower runners take the red line.

Leg 2

The fastest time was run by Jim Mann with 32.0 minutes.
The median time was 44.6 minutes.
It is basically following a ridge.

The major distinction is between runners that went to the intermediate summit (yellow, 25 runners) and those that contoured a bit south of the summit (green, 41 runners). Then, there are also a few that went rather far to the south (red, 4 runners).

There is not really a distinction. For the faster runners it looks like the green line is systematically faster than yellow. But maybe I’m reading to much into it now. Red is something you probably should avoid.

Leg 3

The fastest time was run by Charlie Sharpe with 50.0 minutes.
The median time was 70.2 minutes.
We continue the ridge running. The ridge makes here a wide turn, so the question becomes if you should follow it all the way or if you rather should descend a little and take a shorter way.

The blue runners (29) simply followed the ridge. Then, we have the cyan ones (19) that tried to take a little shortcut. The green runners (11) turned a bit earlier than the cyan ones and joined the yellow ones (8) that turned still earlier from the ridge. Finally, there were three runners that tried the red line, going very low.

Red is clearly a bad idea. Between the other colours, it is less clear. Not enough data, but personally I think that yellow looks rather promising. I’ll probably try that the next time.

Leg 4

The fastest time was run by Jim Mann with 40.7 minutes.
The median time was 65.3 minutes.
During this stage you leave the ridge and get into farmland. Most of the running in the farmland is along either an obvious or a mandatory route. The point where choices can be made is leaving checkpoint 3.

Most of the runners (52) went first a bit to the west before turning south (blue). Of those that started south, 13 turned quickly east (yellow) to join the blue line, while the other four runners get going south for a lot longer. Finally, one runner took a line to the west of all others (green).

Green and red are clearly bad ideas. Between yellow and blue, the most promising looks blue. It is certainly possible to mess it up (some did so), but the results are slightly better than those for yellow. As long as you don’t ask for p-values and such, that is. Just follow the logical line and everything will be fine.

Leg 5

The fastest time was run by Beth Pascall with 58.4 minutes.
The median time was 81.2 minutes.
Most of this leg is across farmland where you have no choice but following the road. The checkpoint is on the top of a mountain (surprise, almost all are) with different choices to get to the top.

Runners come from the west following a track and try to reach the checkpoint at the dot. A first option (green, 34 runners) is following the track to the saddle (or shortly before it) and then take a straight line to the summit. A second option is to leave the track a lot earlier and go again straight for the summit (yellow, 28 runners). This is done in a surprisingly narrow band even though there is no real path. Finally, some (8) runners took a line still further to the south (red). Those lines show a lot less clustering than the other colours.

What do we see? It doesn’t matter a thing. Possibly this is because this is just the end of the leg and the effect of how strongly you ran the rest of the leg is much more important.

Leg 6

The fastest time was run by Jim Mann with 45.0 minutes.
The median time was 64.7 minutes.
Basically, this is again following a ridge and at the end of the path turning left to the summit of a mountain. Halfway you pass a little minor summit where different options were taken and then there is variation in how you climb to the checkpoint. I will consider both parts separately.

Most (41) runners took the green line following the obvious path. Others (14 runners, cyan) sticked closely to the ridge and went over that little summit. Then there are the yellow (13 runners) and red (2 runners) lines. Those look suspiciously like following the wrong ridge, where the red runners even managed to get turned around in the fog.

Red is very bad. No surprise there. Yellow is also bad, but the interesting question betwee cyan and green is less clear. The averages are 8.0% for cyan against 8.1% for green, which basically means no difference.
Next, we look at the different options to climb to the checkpoint.

The main bulk of the runners (47, cyan) followed the obvious path. This is clearly the longest option. The red line are seven runners that turned a bit north and followed a line rather parallel to cyan before climbing to the summit. Two runners turned at the same point as the red line, but went then straight to the summit (green). Finally, the yellow line are 14 runners that started like cyan, but tried to shorten the wide turn.

This is rather clear. Follow cyan. It is the easiest way, you can’t get lost and it is the fastest. Red and green look rather desastrous, while yellow holds some promise but is a lot of effort for zero gain.

Leg 7

The fastest time was run by Beth Pascall with 50.5 minutes. She gained five minutes on anyone else.
The median time was 79.3 minutes.
This leg is a long descend to the halfway checkpoint. There are multiple tracks on the mountain and usually some people make terrible detours.

Most (59) runners took the straight cyan line down the hill. We see that some (6) strayed to the east and made an extra turn on an unsurfaced road to get back to the cyan line (yellow). Then there were two who did something similar to the west (green). Finally, three runners took a very long and original way far to the east of the others. There were some more very original tracks, but those belonged to people that did not finish the stage (usually they dropped at CP7), so those are not taken into account in this analysis.

It is no surprise that some of the original options take a very long time on this leg. More surprising to me is that some of the original options are still rather fast. It makes me wonder if the time you lose on this stage is not mainly due to doubting where you are. I know that is not always easy to pin your location down at every intersection. Possibly the most important thing is to keep going in a good direction while knowing where you are on the map. The time you can lose here doubting your position is probably a lot larger than what you lose by not exactly nailing the shortest way.

Leg 8

The fastest time was run by Beth Pascall with 33.1 minutes.
The median time was 55.8 minutes.
Keep again in mind that time include for this leg the time spent in the aid station. Variation in that resting time will probably dominate any difference due to route choices. Especially since this is a short leg of which most follows a mandatory route.

We see that the big majority (64 runners) to the straightforward option (cyan). Some (9) opted for a line parallel to the cyan line (green). And than there were three who tried the green line but did something that looks like getting lost (yellow).

Yellow is obviously bad. You don’t want to do that. Green? Well, not really bad. Some spent a long time, but others were as fast as the cyan ones. I suppose that the slower ones spent a long time trying to fit reality to the map.

Leg 9

The fastest time was run by Jim Mann with 20.1 minutes.
The median time was 30.2 minutes.
This is an obvious leg with no possibility to be original.

Leg 10

The fastest time was run by Jez Bragg with 106.2 minutes.
The median time was 152.7 minutes.
This is a long leg with choices to make in the first half and another choice in the second half.

In the first half the most popular option is to stay high (cyan). This option was chosen by 66 runners. A few tried something else. Usually this is descending a bit earlier than the cyan line and crossing part of the forest (yellow, 4 runners and green, 5 runners). Finally, one runner (Sabrina) was very original and went down immediately after CP9 and stayed low in the valley.

Well, this looks clear to me. Follow cyan. All the other options will make you lose (a lot of) time.

Then, we have the climb to the summit of Pumlumon Fawr where the checkpoint is.

There are multiple optios. A first option is to stay low and follow the valley. There is a small path to the east of the river. The yellow line follows this to the lake at the end of the valley and turns then west to climb to the summit (23 runners). Very similar is green, but those runners turned a bit earlier (11 runners). Then there are those that thought nothing of this path and started climbing the slope from the beginning of the valley. Most stayed level on the wide track, followed that through the valley an turned west at the end of the valley to climb to the summit (cyan, 8 runners). Other thought themselves to good for a track and went cross country over the slope in a somewhat straight line (blue, 33 runners). Finally, one runner (Christopher) was very original and chose a scenic tour to the east, adding in a few extra summits.

Here, it is funny to see how green and cyan are options for the faster runners, while yellow is restricted to slower runners. Blue on the other hand is popular among all. The average percentages are 18.5% (yellow), 18.5% (cyan), 19.1% (green) and 19.5% (blue). It is a close call, but I think that cyan is the preferable option. That is what I will try a next time. But yellow is also a very good option.

Leg 11

The fastest time was run by Damian Hall with 32.7 minutes. He gained almost five minutes on anyone else, which is surprisingly much for such a short leg.
The median time was 61.6 minutes.

If we look at the different options, we see that there are two distinct options. The yellow line (65 runners) cuts the corner a bit, while the red line (11 runners) sticks to the edge of the forest.

The difference in time is not much and the red option was only taken by back of the packers. It is probably simply due to night navigation and people running together or following each others lights.

Day 1
Day 2
Day 4
Day 5

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One Response to How to kill a dragon? Day 3

  1. Jean-Paul Bruwier says:

    Hi Wouter
    I heard you were at our 10 years anniversary of Zatopekmagazine.
    It would have been the opportunity to talk with you.
    I do not know if you remember but we have been exchanging emails about the first edition of Ecotrail, a couple years ago. In 2017 we will finally listen to your advices ;) and we move out the Ecotrail Brussels HQ to the ForĂȘt de Soignes (Hippodrome) to make it greener. Even if the 80 still starts from the Atomium like requestd by Paris.
    Since you know quite well the region, would you be open minded to analyse our routes and give your feedback ?
    Best regards

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