Sudden drops of ELO

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HawkLake
Posts: 14
Joined: 23 July 2023, 16:42

Sudden drops of ELO

Post by HawkLake »

Hi everyone. I just recognized by chance that I had a drop in my ELO points of nearly 70 points from one game to another one. There is no apparent reason for this, since I neither lost a game nor got dismissed from a game. It is just super-random.

When I recognized this bug, I also checked my ELO history of a different game and realized that there has also been another big ELO drop (about30 points this time) some month ago. Again without any apparent reason (no loss or abandonment or smth).

I think that its really quite a shame if you "work" hard to gain a quite high ELO and then lose a huge chunk of it by some bug.

Did anybody else experienced something similar?

edit: see screenshot as an example: https://imgur.com/a/ejQVeuV
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aesche
Posts: 480
Joined: 06 April 2020, 02:31

Re: Sudden drops of ELO

Post by aesche »

There was advanced discussions about ELO decay a while ago, but I‘m not sure it was fully implemented and stayed so.

Edit: Looking at your logs, and how often you play this game, this doesnt make any sense either. So no clue what caused this…
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RicardoRix
Posts: 2540
Joined: 29 April 2012, 23:43

Re: Sudden drops of ELO

Post by RicardoRix »

Never seen this before, extremely strange. I would report it as a bug.
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h_illes
Posts: 381
Joined: 14 March 2022, 20:08

Re: Sudden drops of ELO

Post by h_illes »

If you play Arena, and you had ongoing Arena games which did not finish by the end of the Arena season, those are counted as a loss for one of the players (supposedly whoever has used more time, but this was buggy in the past). However, the games do NOT end at the end of the Arena season, just converted to friendly and continue.

The losses (or wins) from such games affect both Arena rankings and all-time ELO rankings, but the ranking changes are never properly displayed anywhere; after these games are finished, they appear friendly instead, with no rating change indicated anywhere. But it is there.

(This system makes no sense to me either, but I have seen this issue in the past, and I think it could the same for your situation.)
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Jellby
Posts: 3546
Joined: 31 December 2013, 12:22

Re: Sudden drops of ELO

Post by Jellby »

The OP has a bunch of ongoing Arena games of Earth/Erde. I guess a few/most of them counting as a loss towards ELO (and presumably none as a win) can account for the observed behavior.
HawkLake
Posts: 14
Joined: 23 July 2023, 16:42

Re: Sudden drops of ELO

Post by HawkLake »

Jellby wrote: 08 October 2024, 20:48 The OP has a bunch of ongoing Arena games of Earth/Erde. I guess a few/most of them counting as a loss towards ELO (and presumably none as a win) can account for the observed behavior.
Oh dang, that could be the answer to the sudden drop. But it is really weird / not comprehensible for me imho that Arena games turn to friendly games and are counted for ELO at the same time...

Also it seems like you get a penalty when not finishing an arena game because losing almost 70 points with only 2 or 3 games going on seems way too much for a count as a simple loss...
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Jellby
Posts: 3546
Joined: 31 December 2013, 12:22

Re: Sudden drops of ELO

Post by Jellby »

It might be as bad as always counting as -10 (or -20, or whatever appropriate for the K factor), regardless of the opponents' ELO.
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euklid314
Posts: 679
Joined: 06 April 2020, 22:56

Re: Sudden drops of ELO

Post by euklid314 »

Counting unfinished Arena games as a loss was implemented since many players would start a lot of (turn-based) Arena games and finish only those that they would win. They would leave all the games that they might lose unfinished. In this way they boosted their Arena ranking because they had a 100% win rate.

BGA presumably now counts the unfinished games as a quit and adds some ELO penalty on top of the usual ELO loss. This might be unfair in ordinary cases but is well understandable with the history of cheating that I have described above...
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nik592
Posts: 1389
Joined: 16 October 2022, 13:54

Re: Sudden drops of ELO

Post by nik592 »

That probably also explains why there's such a big warning about the approaching end of the Arena season and why you're not allowed to start games right at the end - I've often wondered as I never noticed the ELO drops from unfinished games (and I don't usually have that many leftover).
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ChiefPointThief
Posts: 745
Joined: 14 August 2020, 22:27

Re: Sudden drops of ELO

Post by ChiefPointThief »

euklid314 wrote: 11 October 2024, 08:34 Counting unfinished Arena games as a loss was implemented since many players would start a lot of (turn-based) Arena games and finish only those that they would win. They would leave all the games that they might lose unfinished. In this way they boosted their Arena ranking because they had a 100% win rate.

BGA presumably now counts the unfinished games as a quit and adds some ELO penalty on top of the usual ELO loss. This might be unfair in ordinary cases but is well understandable with the history of cheating that I have described above...
This doesn't stop the "cheating" though. They still gain the advantages in arena which is their goal by using this tactic. I'm also assuming that the player(s) who used less time in these games don't get a elo boost? Which just leaks elo from the field every arena season.

The real issue is that bga needs to do a better job on restricting slow tb games the further it gets into the arena season.
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