introducing the new wftda stats

With great thanks to Michael Watson of Rainy City Roller Derby, the WFTDA has been working to build a new and dynamic system to host rankings and game data. Here is his report of the endeavours he’s undertaken with WFTDA. We are excited to use this new site for the 2019 Postseason and look forward to having you join us for some of our Live Rankings Weekends.

OVER THE PAST YEAR, I’ve been working with WFTDA on something incredibly close to my heart, and I’d like to share about how we got to where we are today. I’m head coach of Rainy City Roller Derby, a creative director, designer and a web developer, and since I first became involved in the sport I have been obsessed with game statistics, records, rankings and the history of the sport of roller derby. I know how powerful great sports stats can be at creating a bigger narrative to the game, and ultimately how stats can empower and envigour fans to watch more games, to be more involved in the storylines of their favourite teams, and to help explain the sport to new attendees. Roller Derby is a sport grown in the internet era, exploding around the world thanks to the sharing of content and ideas, and yet has fallen behind in terms of its technology being able provide instant information and detailed analysis to its dedicated audience. I had a vision to create a new, powerful stats resource that is primarily for fan engagement, a place where visitors can:

  • View Live Rankings
  • See the impact of game results on rankings, instantly
  • See historical records of all sanctioned games since the first sanctioned game, back in 2005
  • See upcoming games and tournaments with ease
  • View cool, sharable team stats

On top of this, I also knew there was another whole dimension to sports stats — player data. WFTDA is not short of player data information. The amazing Stats Books team has been archiving this information for years, and the data is intact but inaccessible. At present, simple information that would be wonderful to better fan engagement is simply missing from our world. Information such as:

  • Best jammer of the year
  • Clean overview information from each game, highlighting best performers
  • Most prolific player of the season
  • Penalty stats per season per league

I knew that player data would become a bigger undertaking than games and results, so we set out on a plan together to bring games and rankings data to the community first, in a new, universal stats system that is ready to be expanded upon in the future. A system that will one day house all key statistics for our amazing sport, all in one place. Before work began, we made sure we had some key philosophical goals in place for the project:

  • Aim towards one central place for all WFTDA sports stats
  • Build in a way that’s expandable and adaptable for the future
  • Build a universal API alongside the system to allow for community developers to create using our data

So with a long term strategy and a clear initial goal in place, the long road through to getting the new website from a dream to a reality began. I’ll be diving into some of the challenges I’ve faced along the way, some of the features that we have, how WFTDA sanctioning and rankings works behind the scenes, and what we’ve had to change to make this a reality.


Designing a cool, accessible website that allows people to view leagues, results and rankings data is one thing, but as so often is the case with large digital transformation projects like this, the biggest obstacle revolves around incompatible internal processes and messy data.

The first few months of the project involved a deep analysis of how WFTDA carry out their sanctioning processes, results processes and rankings processes. I’m constantly in awe of all the amazing volunteers involved in our sport, and the sheer amount of conversations and late night Skype calls with different volunteers, hearing how they approve sanctioning, how they submit games, verify results and confirm monthly rankings is staggering. It became apparent that in order to achieve our goal of creating a system that allows instant results and rankings to be displayed, we would have to rework several internal processes.

A new goal emerged from the project, not only to make a great final product for the public, but to create a system that drastically reduces volunteer time too, and make the management of leagues, games, results and rankings a smoother process all round. Reduced admin time is a great benefit in its own right, but also paves the way to be able to manage more instant results and changes in rankings in the future.


The decision was made to create a new central admin portal for WFTDA to allow the various committee groups handling game submissions, sanctioning approvals, results submissions and approvals, rankings and league information to manage their data in one place. The majority of work over the past year has involved developing this bespoke system to minimise admin time for the volunteers and to create a robust, expandable system that’s ready to deal with all the oddities we have in our sport- unique ranking algorithms that might change, strength factor challenges, league merges, tournaments, game points.

Publishing rankings is now relatively automatic, with calculations happening on the fly, and a simple push of the button will release these to the public. This is a big step up from the older system which would still rely on a lot of manual effort and Google Sheets.

Since the beginning of the season, the rankings team have been using this new system in tandem with the old rankings calculator. We’ve been working together to add useful features, iron out issues, and get the system to a point where it’s ready to be relied on.

Photo courtesy WFTDA


Bringing through old league information and results was always going to be a challenge, and writing a procedural system that can import all sanctioned games since the beginning of time was a great challenge. We’ve worked really hard together to uncover all leagues games, unpick conflicting or missing data from the past, restore leagues that have been removed, and aim towards a single source of truth that tells the whole story of the history of our sport. Now that the data has been brought through and polished up, we have access to some really cool sports information that was difficult to uncover before, such as:

  • Which league has played which league the most
  • League’s best ever results
  • League’s closest games
  • League’s highest ever rank

By December 2018 we had a reliable system for migrating the old game and rankings data and a new, single source of truth that we could rely on. It felt like a major step in the creation of the new system.


A large question we had to answer was: how do we introduce live rankings to the community, but still keep the concept of monthly rankings intact? Monthly rankings are used for weights calculations, and so to simply change to live rankings overnight would cause too much of a sudden change.

We also knew old data had to be preserved as it was displayed to the public- we can’t go about changing history, and that data is precious. So we devised a method where can run both- a new system for the rankings team to easily publish monthly rankings when they are ready, while also giving live rankings to the public alongside, in beta. This way, league weights will continue to be updated monthly, for the sake of calculating game points, but the power of live rankings as a fan engagement tool, to see immediate impact of results on rankings, can be launched right away.

In order to really get the most out of live rankings in the future, we need to have a consistent method for WFTDA to be verifying and submitting results as quickly and reliably as possible. We long for the day in the future where our systems are so tight, every single sanctioned game ends up published on the site at the official final whistle. For the time being, we’ll be running some trials on this.

We’re setting up some special showcase Live Rankings Weekends. You can find out all about these on the WFTDA social media accounts and at We’re setting up internal processes ready for instant submission of results, so that fans will immediately see changes to rankings and see information show up on site. We’ll be using these tournaments as a learning period, to see how submitting results instantly works, what kind of obstacles it throws up, and how we can manage this universally in the future.


The public site has been designed to show off stats in the most user friendly, pleasant way. I’ve put a big focus on useful, bitesize information rather than intense, deep dive tables, and as such have created a system that’s light and breezy, telling cool, useful stories to beginners to the sport, as well as providing some deeper information for those that want it. I have been designing for mobile phones predominantly, as I know what it’s like during a tournament or game. I can see people looking up information on their phones, and I want WFTDA to be a key resource to discover the impact of games, to see the history of the competitors, and bigger storyline of the game at hand. I want people to easily see:

  • Have these teams played each other before?
  • What’s their record against each other?
  • Who’s the highest rank?
  • How is their form?
  • What are their latest results like?
  • Who do they have coming up?

These questions really help paint a better picture of the game and the bigger storylines, and to have quick, easy access to this will be huge for fandom. Eventually to be able to look up who the strongest jammers are, or who their best blockers are, will be even more powerful.

Another really important question that comes up during sanctioned games is the ageold “but what score do they NEED?” question. Rankings are important, and often in roller derby we have stronger teams playing weaker ones, each with their own goals of expected scores to achieve their rankings goals. This can be confusing to fans, especially if they’re left in the dark, so I’ve created a simple forecast tool that allows fans to understand what score their team will need to maintain ranking position, and to better comprehend “good” or “bad” outcomes.

Some of these stats are great assets for leagues to integrate within their own websites, and we’re looking at creating a series of widgets that’ll allow anyone to tap into this data and bring their websites to life, in the near future.


As I’ve discussed, player data is a big long-term goal for me and for WFTDA. The biggest challenge will be the analysis and interpretation of thousands of statsbooks and then working towards a grander goal of creating a system that can ingest jamby-jam data, interact with scoreboards, and provide even more instant and granular data for the fans.

Another important feature for the future will be to create a better, improved tournament system that allows for the rollout of tournaments with their own websites, news, brackets, prediction competitions and live rankings all in one place, feeding directly into our core games system. Building a universal system, with an API alongside, allows us to develop with freedom, knowing that we’re ready to be responsive and dynamic to any opportunities that come our way.

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