Board Game Arena

Hello, is it normal?

https://it.boardgamearena.com/table?table=544532283

We had almost the same Elo before the game, I Lost and got a -21 while my opponent got a +10, really strange...

BOARDGHEIMER wrote: ↑01 August 2024, 16:29 Hello, is it normal?

https://it.boardgamearena.com/table?table=544532283

We had almost the same Elo before the game, I Lost and got a -21 while my opponent got a +10, really strange...

The first thing that comes to mind is that your K factor was 40 when the game began and N4rishm4's was 20, which would explain the roughly 2x factor in the difference in the ELO change between you two despite starting with about the same ELO. Someone else can confirm that your K factor is based on how many games you've completed when a game begins, not when it ends. Now that you have 20 completed games your K factor has been reduced to and will remain at 20, which provides the smallest variation. Read "How is my ELO ranking computed?" in the FAQ for more information.

Still think It Is not Fair but thank you for your replay.
I do not even know how to see my K factor from smartphone ah ah
Thank you again

Elo is not about being fair, it's about being a reasonable estimation for your skill. Your elo changed more because the system felt less sure about your previous elo than about the other player's (or because of some bug or wrong assumption). Stop looking at elo changes as rewards and punishments, and you may be a happier person.

BOARDGHEIMER wrote: ↑02 August 2024, 06:31 Still think It Is not Fair but thank you for your replay.
I do not even know how to see my K factor from smartphone ah ah
Thank you again

It is completely fair for the K factor to start high and gradually decrease because when you first play any game your Elo is almost certainly inaccurate (i.e., it's not exactly what the default rating is) and the purpose is for it to trend toward its equilibrium as quickly as possible which is accomplished by having big swings early on. It is a feature of rating systems of chess federations as well.

BOARDGHEIMER wrote: ↑02 August 2024, 06:31 Still think It Is not Fair but thank you for your replay.
I do not even know how to see my K factor from smartphone ah ah
Thank you again

If the K factor would not have been high in your first 20 games your Elo would still be around 200 at the moment and not 400. You seem to be a decent player and the high K factor helped you to get to a relatively high ELO fast. You cant have high K factors at your wins and low K factors at your losses...

euklid314 wrote: ↑02 August 2024, 09:42 If the K factor would not have been high in your first 20 games your Elo would still be around 200 at the moment and not 400. You seem to be a decent player and the high K factor helped you to get to a relatively high ELO fast. You cant have high K factors at your wins and low K factors at your losses...

Yeah it is funny how games where their opponent loses x ELO but they gain 2x ELO is perfectly fine, but somehow it becomes unfair the other way.

I think the ELO bonuses and penalties for group games is a bit extreme. It would be better to take the average bonus/penalty instead of the cumulative. This would make the ELO more stable and hew closer to the number in my head of what I think my score SHOULD be, based on the levels of the players I typically win or lose against.