What is the share of climbers who can send 8a or 9a?

In our previous post, we have looked at the distribution of grades across almost 3 million rock climbing ascents in the 8a.nu data. Today, we will take a very similar approach and look at the highest climbing grade mastered by more than 30,000 rock climbers (both male and female).

The average peak grade is closely below 7b, and 8a is the mode grade (the most frequent individual maximum grade). In contrast to the distribution of all ascents, we do not see a clustering around 7a for the individual top performance. There are a similar number of 7a to 7c climbers. There are however much more climbers with an 8a limit than we would expect for a smooth distribution. Keeping this in mind, let us gauge how much more difficult is 9a compared to 8a and 7a: In the 8a.nu database, there are more than 4 times as many climbers who have achieved 7a compared to 8a, but there are almost 50 times as many climbers who sent 8a than 9a. Moreover, this is most likely a severe underestimation of the difficulty since I assume that elite climbers are over-represented at 8a.nu compared to other climbers (and top-level ascents which help you to receive publicity and sponsors are recorded more often).

Here, you can also see the distribution of the maximum grade achieved separately for male and female climbers only (85% of all registered climbers in the database are male). Let us start with female climbers:

For female climbers, the average top grade is close to 6c+ and 7a is the most frequently recorded top grade. Male climber's average grade is close to 7a+ and 8a is for them the mode grade. Interestingly, there are much more females who report 6a, 6b or 6c as peak grade compared to 6a+, 6b+ or 6c+ but we do not find this pattern for men.

What is the average difficulty of a climbing route?

In this post, we will take a look at rock climbing ascents recorded in the 8a.nu data (or to be more precise their grades). This post is about approximately 2.7 m ascents, often multiple ascents by one climber (we will look in a future post at the maximum climbing performance of climbers).

The following graph shows the French grade distribution of all ascents:

What is immediate obvious is that the distribution is not symmetric. First, there are few ascents below the French grade of 6a. We second find a remarkable uniform number of records between 6c and 6c+. The most number of entries is for 7a (or 5.11d) routes. Most 8a.nu user climber probably rather well and are reluctant to enter ascents below 7a in the database.

Here the same plot truncated below 7a and with percentages of ascents (7a and higher).

Interestingly, there are more French 8a routes recorded than 7c+, and a noticeable drop from 8a to 8a+. A possible explanation is that the French 8a grade could constitute a reference. Climbers might put more effort and try more 8a routes than either 7c+ or 8a+ (and perhaps are first ascenders more willing to grade a route 8a). This would also explain the large share of 7a routes compared to 7a+ (and perhaps 6c+). But perhaps there are other explanations I am not aware of? It is also worth mentioning that there is no spike at 9a, perhaps because of greater scrutiny?