Dear Quidkids,

The day you may or may not have been dreading is finally here. IQA Rankings are starting up again, starting… now! You can go see them at the Standings page. Some of you were not expecting rankings to happen this half-season, since it is a shortened season without a World Cup in it, but that sounded to us like a great testbed for trying out a new way to rank teams, without immediate changes to who might qualify for what. These standings will reset with the new full season in the Summer or Fall.

These next few months, though, are a great time to still enter your games since November, and see how they affect your rank. We now have an open-ranking system, meaning that we have both an in-depth explanation of how the algorithm works (see below) and even a step-by-step technical one for those math-inclined. The actual code that powers the algorithm is even open source and available to the public. The code is built on a custom quidditch-ranking library that can be used to create any custom ranking algorithm.

The idea behind the open system is two-fold:

1. You should know how your team is placed the way it is. No smoke and mirrors, only numbers that your team creates through its playing ability. We want you to understand what factors move a team up and down in the standings
2. We want you to help improve it! If you believe there is a better method, we want to hear it. Maybe you’ve thought of a crucial aspect of the game that isn’t accounted for in the present algorithm. Tell us! The reason why we’re doing rankings in this half-season is so that we can test out this algorithm. If (knock on broom) it totally falls apart and doesn’t work this season, there is plenty of time to revise and come up with better solutions. We want you to be a part of that improvement while we have a great opportunity in the next few months to tweak things without major consequence.

Dan Panzarella
CTO

Hello, IQA!

The Game Play department has spent months and months hashing out the final details of the rankings system for the upcoming mini-season, and we’ve finally completed it! With any luck, this will be the rankings system for the foreseeable future.

You can see this explanation here!

Thanks, and happy quidditching!

Will Hack
IQA Game Play Director

update 3/16: The technical explanation has been updated due to an inaccuracy in the described formula. The Gameplay department had decided earlier to remove the 1.1x boost for playing more than 5 games. The actual algorithm updated at that time to remove the boost (see the source code for yourself, iqa.js, line 384) but the explanation wasn’t updated to reflect that change, and still described a boost that wasn’t used. The explanation page has been updated to reflect the algorithm’s correct and present state.