Breaking down the Elo / Rating systems

[Klaud07]

What's going on with the system anyway? It started ~ a few weeks ago:



1 place: +20 points
2 place: -1 point
3 place: -1 point

Another game:



1 place: +17 points
2 place: +1 point
3 place: -2 points

It turns out 2 games and 2 second places and + 0 points in total...

In a game not with weak opponents.

Here's today's game:



Even some pennies are awarded for a winning...

In a game not with weak opponents.

Despite the fact that my rating is not high.

At the same time, losses for a defeat are 2.5 - 3 times more points than for a winning.

Why does Alfyyj get more for second place than I get for first, while on average I get nothing at all for second place, as in the pictures above?

Why did you ruin the system, which were already not easy to climb?

[euklid314]

In all these 3 games you got penalized because you had too many consecutive wins against one of the opponents.

In two cases you had 6 consecutive wins (against Alfyyj), thus the win against him does not count at all.
In one case you had 3 consecutive wins (against Marjaurie), thus the win against him does count only 75% of a normal win.

If you mouse-over your new elo value you will see a detailed break-down of the elo change.

[Jellby]

If you don't like the consecutive wins adjustment, you may be able to find the thread where it was announced/discussed and complain there.

[Nekojin]

Also note that Alfyyj (third game) got more points because she wasn't expected to beat paubo. Alfyyj started with a rating of 189, paubo started at 215. It's close enough that it's not a huge shift, but just being across that line makes a notable difference. Alfyyj was also not penalized for losing to you very much because you (at 307) were much higher than her (at 189), and a win was expected.

(I honestly don't know how the ELO works with consecutive losses - does it zero those out, too? Was Alfyyj given zero points for the sixth consecutive loss to the OP?)

[Jellby]

(I honestly don't know how the ELO works with consecutive losses - does it zero those out, too? Was Alfyyj given zero points for the sixth consecutive loss to the OP?)

Yes (since relatively recently, I believe). And yes. You can see it in the the hover display.

[Klaud07]

Thanks to everyone who took part in the discussion and enlightened about the system. Nevertheless, I think that the system does not work correctly, because all these games were in the arena, where opponents are randomly selected, and the game cannot be canceled.

That is, it is impossible to accuse someone of deliberately picking up opponents while playing in the arena.

[h_illes]

Thanks to everyone who took part in the discussion and enlightened about the system. Nevertheless, I think that the system does not work correctly, because all these games were in the arena, where opponents are randomly selected, and the game cannot be canceled.

That is, it is impossible to accuse someone of deliberately picking up opponents while playing in the arena.

You are absolutely correct about that. Also, this issue has been brought up by many others in the ELO topic (link below). Yet BGA does or says nothing about it.

https://boardgamearena.com/forum/viewtopic.php?t=33785

[Nekojin]

Thanks to everyone who took part in the discussion and enlightened about the system. Nevertheless, I think that the system does not work correctly, because all these games were in the arena, where opponents are randomly selected, and the game cannot be canceled.

That is, it is impossible to accuse someone of deliberately picking up opponents while playing in the arena.

It's not impossible at all. Two people, communicating through some other channel (Discord, perhaps), both start searching for the same game at the same moment, makes it more likely that they'll be paired, particularly if the game is relatively low population or if it's at a slow time of day.

I'm not saying that's what the OP was doing, just pointing out that the idea of coordinated collusion in Arena being impossible is ill-founded. That said, it's also possible for the same people to end up playing against each other, again if it's low-pop or slow time, entirely by accident.

[nik592]

I'm not saying that's what the OP was doing, just pointing out that the idea of coordinated collusion in Arena being impossible is ill-founded.

And such collusion is against the rules of Arena (not saying it doesn't happen, but it's not the intention). Meaning users who play by the rules and don't collude to select their opponents are getting random, blind opponents, meaning that if you're repeatedly hitting the same user (and your ELO gain is going down due to consecutive wins), you have no control over that. That's not power levelling, that's just playing Arena. While the idea is to punish people who collude in order to power level (though honestly, if you were doing that, you'd do it outside Arena cause it's easier), it's mostly punishing those who are doing the right thing. Which is a problem.

I get that if they excluded Arena from the ELO "fix", then people would just move power levelling from non-Arena to Arena games and collude to select opponents as you say. But the fact remains that they're punishing the majority to deal with a minority problem. And players who really want to power level can still get around it by creating multiple sock puppet accounts to power level against. Or wait 30 days between power levelling sessions (which is a good time to try to build some ELO on your sock puppet account to siphon to your main account - because if you don't keep topping up your sock puppet, eventually, you'll run out of ELO to siphon anyway).

TL;DR - the "fix" punishes those who play by the rules, and doesn't plug all loopholes that can be used to power level anyway. So what was the point?