Analyzing the potential market size of karate clubs in Slovenia — Revision I

Pedro Kostelec
5 min readFeb 27, 2017

In Slovenia, a country of just over 2 million inhabitants, there are over 170 active karate clubs. How are these karate clubs distributed over the area of the country? What is their market reach? Let’s find out.

This research builds upon my previous article titled “Analyzing the market size of karate clubs in Slovenia”. In this revision I use data which is more up to date and higher resolution combined with improved methodologies.

If you don’t have time to read this all, scroll to the Results section and enjoy the graphics!

The goal

The goal of the research is to compute a proxy measure for the potential market size for karate clubs in Slovenia.

Data sources

This study makes use of the following datasets:

Assumptions and constraints

This study makes some assumptions which may affect the results of this study.

First, I assume that the population size of each area is approximately correlated to the number of people training karate in that area. This means that I can use the population in an area as a proxy for the number of karate practitioners.

Second, I assume that people tend to visit karate clubs no further than 10 km from their home. This assumption is somewhat arbitrary and is based on the difficulty of obtaining driving time data for larger distances.

Third, the distance between a person’s home and karate clubs is measured in driving time. I obtained this data from the Google Maps Distance Matrix API. This way I can take into account the uneven terrain of Slovenia and the structure of its road network.

In this revision, I assume that karate practitioners tend to favor karate club near to their home. I model this preference as a half-normal distribution around each club’s location.

This study takes into account geography, distance to other karate clubs and population density. Any other factors that may affect potential market size are not considered.


The largest 15 clubs by potential market size are:

1 — Karate klub Murska Sobota (33684)
2 — DBV TO-TE Rače (31902)
3 — Karate klub Shotokan Kranj (31302)
4 — Shotokan karate klub Grosuplje (29489)
5 — Karate klub Olimpija Ljubljana (29461)
6 — Športno društvo Piramida Novo mesto (28813)
7 — Karate klub Wankan Ihan (27342)
8 — Karate klub MI-KI — Oš Žirovnica (27166)
9 — Akademija bojevniških veščin Ptuj (26788)
10 — Karate klub Trbovlje (24072)
11 — Karate klub Tora (23030)
12 — KBV Dren Krško (22373)
13 — Karate-do klub Ptuj (22323)
14 — Karate Klub Koper (21774)
15 — Karate klub Brežice (21270)

I obtained these results by finding the training locations within a 10km area from each location on the map. Then, I divided the population size of each of these areas between these training locations in proportion to the time needed to drive there. Finally, I added up the potential market sizes for clubs with multiple training locations.

The distribution of potential market size over all clubs looks like this:

Distribution of karate clubs in Slovenia by potential market size.

The yellow line represents the average potential market size which is 11000 people.

The map below shows the top karate clubs together with their potential market area. The blue dots represent the locations of all other karate clubs in the country.

All but one of largest 15 karate clubs are located outside of the two largest cities Ljubljana and Maribor. This shows that the concentration of karate clubs in these towns is already too high. So, if you are thinking of opening a karate club in Ljubljana or Maribor — just don’t. Instead, look for better opportunities in the suburbs.

The capital city Ljubljana is an oasis of choice for karate practitioners. There is so much choice! Highlighted are the largest 5 karate clubs in Ljubljana by potential market size.

In the dataset from Klubi Slovenije very few karate clubs have all their training locations set. Those which do enjoy an “unfair” advantage in this study. It would be interesting to observe how the results would change if all training locations were provided.

Both “Shotokan karate klub Grosuplje and “Karate klub Olimpija Ljubljana” have multiple training addresses. This allows them to increase their potential market size.
The fight for space! The proximity of clubs affects their potential market size.

My hope is that this analysis helps karate clubs in Slovenia to better understand their potential market size. In turn this could help them to better judge investments into marketing to increase the number of people training this martial art.

This study reveals the potential market size for all active karate clubs in Slovenia. But what if you were thinking of opening a new one? Where should you open it to gain the largest possible market size? If you are interested in this question or wish to see similar studies for different sports (e.g. fitnes, judo, gymnastics, …) write me at pedro [at]



Pedro Kostelec

Co-founder and CTO of Sentinel Marine Solutions, Artificial Intelligence graduate from Imperial College London