Ranking system

[mark5000]

There’s been a lot of discussion about this circumstance in the rating tweaks announcement:

2020 Rating and rank tweaks and analysis

tl;dr - Ratings and ranks have been tweaked a little, there should be a bit less volatility in ranks now. Ratings and ranks have been adjusted retroactively. Main changes: We were using fixed windows to update ranks, considering up to 15 games at a time to update your rank. When we got to the 16th game, we’d “commit” your rank and start a new block to update your ranks. We now use a sliding window, so we look at your most recent 15 games (up to 90 days), and use that to update your rank, this…

In short, the rating system uses a 15-game sliding window. It so happens that when you won 3 games yesterday and today against 24k, an 18k and 14k players, you also pushed out wins you had 15 games ago against 16k, 19k and 15k players. As a result, you rank increased very little. Your 1 loss today also pushed a win out of the 15-game window (you had a good win streak there), and so your rank fell more than you probably expected.

There’s been a lot of discussion about this system and whether it should change. But perhaps it’s working as expected. This video explains the concept pretty well (we try to measure the blue line rather than the red one):

Trend and variation