Chart: The Story of K2 Ascents with Tableau – Part 1

K2 Mountain

(Note: I had originally planned to write one single post out of this, but I realized it was too long to digest. So here is the first part. The rest will come soon. Stay tuned!)

K2 is a mighty mountain. Attractive, respected, and dreadful. Normally people think of Everest as the toughest mountain just because it’s the highest peak in the World but it suffices to say that only around 280 people summited K2 so far, whereas more than 2000 people climbed to the top of Mount Everest. has some nice data describing the ascents of K2 (plus many others I suggest you to give a look to), so I thought it would be great to have a chart telling the story of the ascents. I actually did this already some time ago with Excel but I was not very satisfied with the results. So, here I propose a redesign with Tableau.

Tableau is a great tool, even if I have a love & hate relationship with it. And this short series is also a chance to talk a bit about my experience with it.

But first things first. Here is the data if you want to try out your own charts: k2-ascents.csv (please do it … and let me know how it goes!)

Data and Questions

The dataset contains several information but I decided to focus on what can help tell a compelling story. Namely:

  • Nationality of the expedition
  • Route used to climb up to the peak
  • Oxygen if used or not used to climb it up
  • Date of ascent

After several hours spent asking questions and charting I came to the conclusion that the most interesting aspects relate to:

  1. How the nations compare in their quest to reach the peak.
  2. How this relates to the alternative routes attempted (note that conquering a peak from a new route is a big achievement in climbing history).
  3. How the story changes when we consider climbers who used oxygen vs. those who didn’t (by the way, going to 8000m without a mask is totally mad!)


Here is a first set of stories I have been able to build around this data. They mainly concern: the nationality of the expeditions and the routes used to summit the mountain.


This first one shows the number of successful ascents by nation. As you can see the Japanese are by far the best team, even if they seem to have not the best lungs in the world since most of their ascents are with oxygen.

International expeditions hold the record of ascents without oxygen, followed by the Italians, and both seem to prefer tough expeditions without oxygen more than any other (you read my satisfaction between the lines?). The same preference is hold by all the other teams below Italy, with the exception of the Chinese, which together with South-Koreans prefer oxygen.

One open question is whether the nations preferring not to use oxygen have been able to do so because they always take traditional or simpler routes or just because they are “tougher”. But we’ll check that later.

In the next chart you can see the number of distinct routes attempted by each nation. As you can see the Japanese are again on the top. Chinese and South-Korean didn’t attempt too many different routes so this probably means that they really prefer going with oxygen. Or is there another explanation? Let’s give a look to another chart that relates nations with the routes they climbed.

I have sorted the nations according to the number of different routes the nation used (by the way, the sorting capabilities of Tableau are simply amazing). As you can see the Japanese have climber several different routes, many non-conventional ones, and this may explain the reason they have used oxygen so often.

International and Italian expeditions normally take the traditional route, and this may explain why they have been able to do so many ascents without oxygen (can you see my slight disappointment?). The Chines and South-Korean have no excuses by the way: they have been climbing with oxygen mostly on conventional routes!

Several Russian climber did the West Face without oxygen. American, International and French also summited non-conventional routes without oxygen.


Now let’s give a closer look to the routes. K2 has 11 alternative routes. Some of them a really mythical and described by intimidating names like “The Shoulder”, “The Black Pyramid”, “The Bottleneck” “The Magic Line”. In the picture you can get the feeling of what a route is and how they are distributed around the mountain. Please keep in mind how difficult this is: here climbers reach prohibitive altitudes where one single step feels like death.

This first chart shows the distribution of ascents. As you can see the classic “South-East Ridge, Abruzzi Spur” is the most traditional route and by far the most used, followed by the SSE Ridge and the North Ridge.

Again, segmenting the data according to oxygen use reveals interesting facts: the North Ridge and the West Face have been climbed almost exclusively without oxygen. Does it mean they are easier routes, I don’t think so. On the contrary, the West Ridge has been climbed only with oxygen. The 3 major and more common routes are frequently climbed without oxygen with success.

Do you see anything else interesting here? If yes, please let me know. I am looking forward to hear you.

One key lessons learned

I’ll give it straight away: the question and the story you tell are the only thing that matters, not the fanciness of your chart (provided it is not junkchart).

One surprising fact of this first part of the post, after having worked long hours on it, is that the charts I included are relatively simple, just few barcharts. And this would be even more surprising if you had a look to the tens of different and intricate designs I explored with Tableau!

But at some point I refocused my attention and asked myself: “what kind of story do I really want to tell here?“, “where are the interesting questions?“. And as soon as I started answering what was really interesting I discovered that many of these questions could be answered with simple charts like those shown above.

Don’t worry, in the next post you will get some fancier stuff. But if there is one rule I learned out of it (other than realizing how amazing Tableau is) is the one I stated above. Ask your questions first. This is what really counts. Wandering mindlessly around the huge space of possible designs has little value.

Preview of Part 2

In my next post I will provide some temporal analysis of this data. You will see how the ascents distribute over time and how oxygen played a role. Finally, we will see which nations dominated in the struggle to conquer the top by climbing a new route.

Here below a couple of  small teaser :-)

Stay tuned and send me your feedback! Thanks for reading and retweet below if you like it!

4 thoughts on “Chart: The Story of K2 Ascents with Tableau – Part 1

  1. Pingback: Chart: The Story of K2 Ascents with Tableau – Part 2 — Fell in Love with Data

  2. Mel Stephenson

    That’s a great post – I think it is so often the experience that you try so many different things before you end up with a simple, elegant representation of the data. You start with something simple, it becomes more complex as you work on it, you persevere and then it becomes simple again.

    I particularly like the moment about ‘What’s the story? What questions am I answering?’ That part is so important!

    Keep it up!

    1. Enrico Post author

      You are right, this is exactly how it works. Simple … complex … simple. And in general the simplification process is the toughest one. We need some strong mental tools to force ourselves to remove something in place of adding.

      I’d like to write something on it. Let me know if you have any thoughts on it.

      And thanks for commenting!

      P.S. I gave a quick look to your The Data Studio. Cool! I’d like to know more.

  3. Andrzej Kozlowski

    In terms of new routs it would be interesting statistics whose route was attempted the least.Like the difficult 1986 Piotrowski/Kukuczka South Face “Polish Line” that Messner called suicidal and no one attempted ever since.


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