New NAF Glicko Rankings - Updated 21-Jan-20

[Purplegoo]

Hi all,

An exciting NAF ranking development today, as we are introducing our glicko global ranking system!

We have been hosting and maintaining our racial glicko rankings for approximately two years now, and in the background, Nick / mubo and Ketil / kyrre have been working on the best way to implement a ‘global’ ranking using the glicko formula. For those not familiar with the global Elo rankings originally developed by Doubleskulls and now maintained by the Danish community, a global ranking treats all games played as if there is only one Blood Bowl race, and coaches develop one ‘all-in-one’ number. In the case of glicko, Stunty games have been removed from the calculation, as this is intended to improve accuracy.

We hope that you will enjoy tracking your performance via this new ranking, and that those of you that consider yourselves more of a ‘generalist’ or perhaps felt a little undervalued by the racial system now have a reason to keep an eye on the glicko pages on thenaf.net. As a NAF coach, you now have four ways of tracking your performance over time (including global Elo), so lots of interesting numbers to look at!

We are continuing to update and improve the glicko system in the background. The upload is now automated, the numbers update more frequently and we are working on adding glicko to selected screens on the membership website. For those of you that are very keen on the Elo numbers hosted there, fear not, this won’t be intrusive.

Please join me in thanking Nick and Ketil for all of their continued hard work, we hope you enjoy the new system!

Phil / Purplegoo.

(Any questions, bugs or thoughts on anything glicko related, please post in the TFF thread.)

[Itchen Masack]

Oooh a 4th ranking system. We need a heavyweight champion to unite all the belts

[straume]

Good job, guys! (And good job Phil in leading this one)

Q: how does the updates work? Automagically daily or something else?

[kyrre]

Thank you, Loner. Both race and global glicko are (should be) updated automatically every day. Global by race will update around 07.30 UTC*. Global glicko is scheduled to finish around 08.15 UTC*. The calculation is handled off site for time being. While the calculations takes 30 and 10 minutes, the update is instantaneous. You will never see yesterday's numbers mixed with today's numbers in the visible table.

Moving forward we hope to get historical data online as well. The first step is probably to have the monthly numbers downloadable to Excel (CSV).

*) GMT+00 no daylight saving

[Pipey]

This is really cool, thanks for putting it together.

[Topas]

Pretty cool. Love it.

Two topics for discussion:

- global glicko does exclude gobs, ogers and flings. That makes sense to not punish players that play all races compared to players that only play power races (I am guilty!). However, shouldnt it be possible to calculate a baseline per race and for the global rating the difference to each race baseline is used?

- and actually having such a baseline could also inform the race tierings in a more robust way. Although I am fine as is. It would just be interesting.

There is of course some catch 22 in there because if races like orcs are played by more newbies then the race baseline might be underestimated. However, glicko does contain the info if a player is a newbie or not so I think there might be ways around that.

I am happy as is and I know that this would take a lot of effort to get something done, just throwing around some ideas for discussion.

To repeat. I love it that a global ranking is available and I also think having Glicko around in addition to the other ranking is great.

[gcoleman76]

26 races, 2 sets of rankings. We have 52 World Number 1's

Looks like glicko looks at all races as one so only 1 world number 1 with glicko.

Is this correct or does it only.look at your best race?

[Topas]

There are two glickos. One that has a rating for each coach by race combination. And one with an overall rating for each coach.

https://www.thenaf.net/rankings/glicko- ... icko-race/

https://www.thenaf.net/rankings/glicko- ... ko-global/

[rolo]

... shouldnt it be possible to calculate a baseline per race and for the global rating the difference to each race baseline is used?

I'm not sure it's possible to have an objective baseline, since results seem to vary wildly depending on tournament rules; Necromantic seems to do better when they're tier 2+, Halflings seem to do better when they can hire inducements and star players, etc.

[sann0638]

I've done a similar thing with win ratio - any coach can visualise theirs against the standard for that race: https://public.tableau.com/views/NAFGam ... share_link

[Topas]

... shouldnt it be possible to calculate a baseline per race and for the global rating the difference to each race baseline is used?

I'm not sure it's possible to have an objective baseline, since results seem to vary wildly depending on tournament rules; Necromantic seems to do better when they're tier 2+, Halflings seem to do better when they can hire inducements and star players, etc.

Sorry, Rolo. I do not come here to get smart and constructive feedback ...

...

just kidding. Good point.
And I guess then I have to live with the fact that my global glicko is overrated by playing only tier 1

[Topas]

I've done a similar thing with win ratio - any coach can visualise theirs against the standard for that race: https://public.tableau.com/views/NAFGam ... share_link

Awesome. Thanks for the link!

[rolo]

And I guess then I have to live with the fact that my global glicko is overrated by playing only tier 1

There's an easy fix for that, you know!

Know that look of hate/frustration in your opponent's eyes when you tell him that you're playing Dwarves?
You only see joy when playing halflings!

[Wyzard]

And I guess then I have to live with the fact that my global glicko is overrated by playing only tier 1

There's an easy fix for that, you know!

Know that look of hate/frustration in your opponent's eyes when you tell him that you're playing Dwarves?
You only see joy when playing halflings!

You see joy up until you steal all their RR. Then the look is similar to hate/frustration.

[Maverick]

Just imagine the look you get when you land the TTM to go 2 -1 up