Tournament formats and Rating systems

[Dragontamer]

http://research.microsoft.com/mlp/apg/Details.aspx
How similar is this to glicko?

Also I was reading this:
http://www.codinghorror.com/blog/archives/000961.html
and from that found this:
http://www.lifewithalacrity.com/2006/01/ranking_systems.html

Have a nice day.

From a derivation point of view, it looks like Microsoft uses the normal distribution, while Glicko uses the "extreme" distribution. Practically speaking, there is no difference here (and given the fact that the "true skill" link is a non-technical paper, it may infact have been derived from an extreme distribution, but they're not telling us).

According to Glickman, the extreme distribution is just easier to derive all of these formulas, while in practice it doesn't make a difference.

Now, the interesting thing is that in the Glicko paper's I've read, part of the calculations is an "expectation" calculation... a function that calculates the probability that player A wins a match (A vs B). It is absent from that paper, but again, that appears to be non-technical. It just gives the formulas for "TrueSkill".

As for this vs Glicko2...

TrueSkill:

Q: I have been playing a lot of unranked training games and I think I am now a much more skilled player. Will the TrueSkill ranking system be able to identify my new, higher skills? If so, how many games do I have to play before the TrueSkill ranking system knows my new skill?
A:The TrueSkillranking is assuming a small skill change between any two consecutive games in a game mode so it is able to identify your new, higher skill. But, if your skill has completely changed (you became the best player in the world from previously being the worst player in the world), then you would need to play a large number of games. We designed the system such that it would need between 50 - 100 games before the system would be able to track a substantial skill increase/decrease.

On the other hand, Glicko2 realizes that you've been winning too many games in a row and will make it a little faster.



Finally, the last difference is trivial. Glicko/Glicko2's default scale is 1500 == average player, 350 == starting uncertainty. In all the examples of TrueSkill, it seems like the default scale is ~30 for the score, and the default uncertainty is ~8.

 

[COalex]

Apparently Shoddy uses a Glicko2-based rating system now.

 

[Cathy]

It's true. I was intrigued after reading about Glicko2 and decided to implement it. There is a page about the ladder system here.