# Building A Table Tennis Ranking Model

I wrote a post about building a table tennis ranking model over at Rubikloud:

It uses Bradley-Terry probability model to predict the outcome of pair-wise comparisons (e.g. games or matches). I describe an easy algorithm for fitting the model (via MM-algorithms) as well as adding a simple Bayesian prior to handle ill-defined cases. I even have some code on Github so you can build your own ranking system using Google sheets.

Here's a blurb:

Many of our Rubikrew are big fans of table tennis, in fact, we’ve held an annual table tennis tournament for all the employees for three years running (and I’m the reigning champion). It’s an incredibly fun event where everyone in the company gets involved from the tournament participants to the spectators who provide lively play-by-play commentary.

Unfortunately, not everyone gets to participate either due to travel and scheduling issues, or by the fact that they miss the actual tournament period in the case of our interns and co-op students. Another downside is that the event is a single-elimination tournament, so while it has a clear winner the ranking of the participants is not clear.

Being a data scientist, I identified this as a thorny issue for our Rubikrew table tennis players. So, I did what any data scientist would do and I built a model.

Enjoy!