Elo loss after server crash

[nyophex]

Today around 2 pm CEST the BGA servers crashed, resulting in problems with tables and logins for several minutes and abandoned games. While behaviour score changes were revertes, ELO change from lost/won games remains. Shoudln't that also be reverted?

My affected game: https://boardgamearena.com/table?table=301601863

Greetz!

[Jellby]

No, because ELO changes have a cascading effect. Reverting an ELO change should imply recalculating all ELO changes of later games, not only of the affected players, but of all the players who played with them, and so on. And what if a player joined a table/arena they should not have been able to after the correction?

[Silene]

No, because ELO changes have a cascading effect. Reverting an ELO change should imply recalculating all ELO changes of later games, not only of the affected players, but of all the players who played with them, and so on. And what if a player joined a table/arena they should not have been able to after the correction?

Tbh I don't think the cascading effect needs to be much of an issue. It's not like you would have to recalculate everything on previous games just because you add back some points to someone (possibly after other results). The "should not have been able to join" would be the same for cases, where you join a table and during it's progress, other TB-tables end, making your elo at the end of THIS game not what it was supposed to be.

Considering it is possible to reset a player's elo to 100 after cheating was detected (surprisingly without removing gained achievements) - why not "reset" a player's elo to X+(lost points) when server-errors were detected and repaired.

But I guess those ELO-resets to 100 are something that is done manually in rare cases, which obviously can't be done for hundreds of players after a server crash. So to handle this, some dirty elo-manipulating functions would need to be developed and I imagine why that wouldn't have a very high priority - even if it's painful to some people sometimes to lose ELO in this way.

[Jellby]

The point is not that the cascading change must be done, but that if player A thinks their ELO loss is unfair, player B (who beat A after the loss) may think it unfair too that they had a lower ELO gain than deserved. At which point do you stop and say that the difference is too small and you shouldn't care?

[Silene]

The point is not that the cascading change must be done, but that if player A thinks their ELO loss is unfair, player B (who beat A after the loss) may think it unfair too that they had a lower ELO gain than deserved. At which point do you stop and say that the difference is too small and you shouldn't care?

The impact is very different. While a lost game (that you got kicked from because of server crash) might give you -20, the opponnent you played inbetween only had a very small loss from playing vs a now underrated player (maybe -2?) compared to that.
If you think cascading fairness is an issue, then it would even be more relevant to fix elo, because then at least the cost in the cascade is prevented for games that were played AFTER the fix. Also there are usually only few games played between the issue and the fix.