Estimate ELO gain/lose isn't working properly

[Onigeshi]

https://www.faceit.com/en/csgo/room/1-67f68fb9-6d97-4156-b31b-26904c697f0e

I forgot to screenshot the lobby before, but after the last update the margin of error has increased
exponentially.. in the lobby linked above it was showing that we will gain +15, yet we gain only +12.. remember that before this last update I've never had a margin of error bigger than +/-1 like it was mentioned anyway..

I'll try to screenshot a lobby before and after it ended and edit this post.. at the moment I forgot to make a screenshot before so you could have the ELO of the players and the averages..

[timche]

We didn't change the calculation. Sometimes it can happen that the margin is higher, but rarely.

[Onigeshi]

https://imgur.com/a/RhT9AN5

@timche like I told you, it may not be your fault, it may be a change made by faceit that broke things.. but after the last update this is a thing.. and its not that rare.. its been for like 4-5 games in a row..

[timche]

Okay, that's weird. Will have a look at this, thanks.

[MaBauMeBad]

+1 still a thing

[airen29]

Allright. So it does work good if a player plays solo game.

Once there is a stack of 3+ people it calculates elo wrong.

[timche]

Since FACEIT has introduced Elo gain/loss penalties for teams with too much Elo difference, there's currently no way for us to make precise calculations.

[h0lmiew]

Since FACEIT has introduced Elo gain/loss penalties for teams with too much Elo difference, there's currently no way for us to make precise calculations.

From playing and experiencing ELO penalty from many many games, it looks to me like there is a pattern in which the K-Factor is scaled depending on the spread of your teammates ELO in a 5-man stack, into three buckets.

The normal K-factor is 24, which is then scaled as usual if the average ELO of both teams is not even. So for an even match with 50%/50% for both teams, you win or lose 24 ELO points, if there is no ELO penalty applied.

But, the K-Factor is scaled to 16, or 8, depending on how wide the spread of ELO the team members have, in terms of highest to lowest, if too wide.

The following buckets are the ELO span threshold (from lowest to highest rated player) for a 5-man stack team:

• 0-1200 you do not get any ELO penalty, and you will typically get or lose about 24 ELO points, for an even match.
• 1200 to 2000 you get an ELO penalty that reduces your typical ELO to 16.
• Over 2000 spread, you get an ELO penalty that reduces your typical ELO to 8.

E.g. if you have a 3200 ELO and an 1100 ELO player, you have a span of 2100, and will win or lose roughly 8 ELO.

If you take these ranges into account when predicting ELO to win or lose, I believe it should fit.