Site Ratings Period



From the docs people helpfully linked:

The Glicko-2 system works best when the number of games in a rating period is moderate to large, say an average of at least 10-15 games per player in a rating period. The length of time for a rating period is at the discretion of the administrator.

Following on my previous post, I was hoping that someone could say what the ratings period for OGS is. (Strangely, details of the Glicko math used were entirely absent, despite the fact everyone knew the buzzword.)

Your score updates each game, but a ratings period of a single game is a major violation of the Glicko math.

So I’m wondering:

  1. How are we updating scores each game?
  2. What is the Glicko ratings period?


I don’t have any proof, I’m just recalling (possibly erroneously) what I have read. My understanding is that

  • Our ranks are updated with a provisional result each game

  • The ratings period is a 3-4 weeks (can’t recall precisely).


In my case I’m playing correspondence games only and as these take a long time to finish, sometimes my game record goes unaltered for weeks. How does this affect the calculations when there are only a few (if any) games every 3-4 weeks available in the records?

  1. When a ranked game ends, both you and your opponent get their new rating calculated based on their tally
  2. 15 games or 30 days
    OGS has a new Glicko-2 based rating system!


Using this technique consistently produced better results in our experiments, and we later found that Prof. Glickman applied some techniques akin to this in his Glicko-Boost work in 2010, which made us feel better about doing this as opposed to simply using the original ratings.

Reading that, it sounds like we actually use a “folk math” version of Glicko, and not any of the official Glicko methods – exactly like I’d suggested (and been rudely shot down about).

I’m very curious how they tested this, because it sounds like that testing is the only thing underpinning the entire ratings system of the website, which is a “folk math” system modified from a real one by the admins of this website, and not any sort of standard rating system at all.

I also think people need to be more honest about this: We didn’t implement Glicko or Glicko2, we implemented OGSGlicko, which has none of the theoretical support those other two did. In light of this, the responses I got questioning the ratings system were really inappropriate.

You guys made “folk math”, and it works badly.

Could one of the admins chime in on how they tested their customized Glicko method?

Strangely, despite having a section called “implementation notes for the curious” you left out the key detail of your implementation. That doesn’t instill confidence.