Football may be a unique industry, but at its core, it’s still a business. Like any company, clubs are constantly seeking ways to improve their financial standing, whether through the transfer market, commercial deals, merchandise, or ticket sales. To make the best decisions, more clubs are turning to data - that's where experts like Chelsea Disseldorp come in.
A former Dutch youth international and professional footballer in the Eredivisie, Chelsea has spent years honing her data analytics and business development skills inside and outside the football industry. Drawing on this expertise, she launched her own freelance consultancy - Chelsea Data Consultancy - where she works with professional clubs and data providers on a wide range of projects.
In this interview, she shares insights into the evolving role of data in football and how clubs are using data to reshape their decision making processes.
The interview has been condensed and lightly edited for grammar and clarity.
[ Playing professional football ]
When I was 13, I joined the national youth teams here in the Netherlands. In total I earned 22 youth caps from the age of 13 to 16. After my high school graduation, I studied Information Science (at university) and combined this with playing football. During my bachelor’s degree, I played 3 seasons in the Eredivisie, the top league in the Netherlands - two for PEC Zwolle and one for FC Utrecht.
There were some advantages, like free accommodation, but it was mostly still a ‘hobby’, even though it was the highest professional level in the Netherlands - you still had to study or work alongside. After my studies I joined KPMG as a consultant. At that time, I didn’t expect to be working in football again!
[ How did you end up working in football again after KPMG? ]
At KPMG, I was initially focused on Enterprise Solutions & Systems before moving quickly to Data Analytics. For the first couple of years, I had projects in multiple sectors, but nothing like the sports sector. Then after 3 years or so, KPMG was organizing a sports analytics conference. A colleague of mine, Paul Adriani, was organizing the conference and asked for help. The conference (at the Johan Cruyff Arena in Amsterdam) went really well and afterward, my colleague proposed to continue with a sports analytics proposition at KPMG to build on the success of the conference.
We had a really great couple of years, did a lot of business development and spoke with a lot of organizations - including football clubs, stadiums and sports data companies. We also worked on projects in different sports including a pro cycling team. During that time, I really realized I can work in sports.
I was still at KPMG but I got to know more people and wanted to see if I could join a sports organization as a data analyst or a Business Intelligence (BI) specialist or something like that. As I was looking around, I came across a vacancy at Feyenoord, and they hired me - this was 5 years ago.
At the time, there was not much data related work in the club - they worked with some external companies and even the CIO himself did some work. It was really up to me to build a data team from scratch. My manager said, ‘take your laptop to each department and see what they want!’ So I was still like a consultant, fulfilling the data and visualisation requirements by doing the end-to-end data work.
At first, I focused a lot on the business departments - merchandising, ticketing, marketing, hospitality, HR, finance, etc. But, of course I’m also interested in the football side - I want to work with them as well! - and I started to work a lot with the scouting/player recruitment department.
[ How similar was the work (technically) to the work you did at KPMG? ]
Even though the sector was different, and a football club is a very ‘special’ organization, it was technically quite similar. I worked with the same tech stack (Microsoft) and many of the same systems and tools. Maybe it was even a bit more technical than when I was a consultant because, as a consultant I also did more strategic projects. The biggest difference was probably the ‘maturity of data’, at that time, that was different in sports compared to other big sectors. This was really nice because you get the chance to build something from scratch and make an impact. You can see now, 5 years later, how much has been done.
I had a lot of things to do and saw a lot of sides of the industry. I spoke with data providers, built my own data team and had a great time.
[ I think when people hear ‘football data analyst’ they’re thinking about the person making pizza charts and things like that, you do some different things. Can you give an example of a project you worked on? ]
There’s something related to player recruitment that I’ve built for multiple clubs, tailored to their specific requirements, by now! Quite often clubs get a lot of tips from player agents - via phone, email, WhatsApp or just personally - but many people at the club get these tips and they don’t track this information very well.
I built a ‘player registration website’ where the club can share the player profiles they are looking for and agents can submit players fitting certain criteria. All this is then submitted to a central database inside the club. You can combine different sources and combine them so that anyone at the club can easily see all the relevant data for that player, from basics like name and date of birth to tracking & event data, player values and more. Then, a scout or the sporting director can see all the details about any player in a dashboard. Storing all this data centrally makes the club less dependent on the people working there and makes it much easier to use data in scouting.
It sounds easy but there’s a big process for getting all the data and connecting everything so everyone can use it.
[ How is the cooperation between you and the ‘non-technical’ people at the club? Did you work with the scouting department or the sporting director while building this? ]
In this case, the website is mainly used by agents, so the sporting director or the people working in the scouting department, they know a bit better what agents want or don’t want. In general, it needs to be simple and quick to register a player. So I speak with them and make a design - a mock up - and show them how it will look and get feedback.
It’s important, even in the very beginning, to involve the end users but you keep them away from the technical infrastructure and just focus on the frontend - what they will see and use. At smaller clubs, you will usually do everything yourself, including talking to the users and making the backend and frontend. At bigger clubs, where the data team is usually bigger, there might be analysts who take charge of certain parts of the process.
"It’s important, even in the very beginning, to involve the end users"
[ What led you to leaving a club and starting on your own as a freelancer? ]
I like to do different things! I wanted to see different organizations, like I did as a consultant, and do different things. Of course, I also like working a bit longer for the same organization but then I also did different things, different projects.
I thought, I have quite a good network and CV - I played professional football, worked in football, I have my certificates, let’s give it a try and see if I can find some work. It’s a very competitive world and it’s a niche sector. I think I have a niche profile though and that can make the difference between other people that might have the technical knowledge only, but are missing the sector, the football knowledge.
[ How has your own background as a professional footballer impacted this part of your career? ]
It’s really helpful to already know what people want to see and what they are talking about when they use technical terms. It’s the same with any sector but if you aren’t interested in that industry or haven’t worked in it, there are a lot of abbreviations and terms - it’s important to speak the same ‘language’.
A lot of data providers provide thousands of clubs with the same data - this isn’t very helpful if you want to gain an advantage. You can really make a difference if you can translate this into helpful visuals based, for example, on the club’s tactics or ‘DNA’. If you’ve played yourself, especially at a professional level, you know what metrics the players want to know and what you don’t want to bother them with and is better for a coach or a trainer to see. If you follow football and understand the club, it’s already really helpful.
[ How do you find clients? Do you pitch projects or are people/clubs coming to you? ]
It's a combination of both. I’ve gotten some projects from reaching out to people in my network and just having a meeting. I think it helps if you already know each other a bit or if you’ve worked together previously so they know what you can do. Sometimes, people just find me on LinkedIn, see the projects I’ve done and reach out to me that way.
The timing is quite important, because you need to reach out at the moment when they are really looking for something and when there is a budget available. Sometimes, especially for smaller projects, clubs want to hire a freelancer but sometimes they are looking to hire someone permanently, or on a contract if someone is on leave or holiday. In the end, you need to invest time in getting to know a lot of people in football and have some luck.
One of the advantages of being a freelancer is you see so many different organizations and learn different things at each one. Someone in the same club for years and years might not have that broader sense of what’s happening at other clubs.
"One of the advantages of being a freelancer is you see so many different organizations and learn different things at each one"
[ What are some reasons clubs choose to hire a freelancer instead of building an in-house team? ]
If I look at the freelance projects I’ve done. They’re often very tailored - so the club wants to have a specific thing done, I’ve done it before and they want me to do it for them quickly. Sometimes it’s because the work is flexible, they don’t need the same amount of hours each week so it’s better to hire someone short term. For example, if a project is, in total, 30 working days and then it’s done - it might make sense to hire a freelancer instead of a permanent employee. I have also worked in an interim role to replace somebody who was on leave for a longer period. Organizations often look for freelancers then as well.
[ How have data departments changed since you started in this industry? ]
I think the biggest difference is in the amount of clubs that have a data department. When I started, only the bigger clubs in the Netherlands were starting to build a data department but now, even the smaller clubs - all of the Eredivisie clubs and some in the second division have people in-house that are working with data.
It’s not just clubs, football associations are also collaborating with data providers. Some buy all the data and make the data available for every club so they can use the data to improve and get better results.
Smaller clubs are mostly working with the front end tools of data providers while bigger clubs have more people working in-house and can tailor their tools to their own club culture, but sporting directors know they have to do something with data! Football is a quite conservative industry but still, everyone wants to do something with it.
Of course, it's still important to not trust only the data. A good example is in physical data, things like tracking the ‘load’ of a player during training - even if a player is still in the ‘green zone’ maybe they are having issues personally, away from the pitch and would benefit from a lower load - but the data won’t tell you that.
[ What is the most valuable data that isn’t related to the actual match on the pitch? ]
In the end, it's all about what's happening on the pitch, that's the business model of a club - if you perform, more money comes in and you can buy better players. But next to the pitch, there's a whole business which is quite special if you compare it to other industries. At Nike, you can buy merchandise and at Ticketmaster, you can buy tickets but a football club has both of these together.
The commercial side is a growing percentage of a club’s total revenue and data can be used in different ways. If you're looking for a new sponsor, you can use data to show what the results of the previous sponsor, or other clubs’ sponsors, have been. More often, clubs are creating a ‘360 degree’ image of a supporter - finding out what matches an individual fan attends, when they arrive, if they buy food and drinks or a shirt. This can help a club predict revenue and tailor marketing campaigns.
There are plenty of examples of how you can use data to get to know your supporters and the whole fan base to, well, earn more money, but also to improve engagement and fan experience.