Board Game Arena

Have a look and upvote if you think this is a problem.
https://boardgamearena.com/bug?id=46582

To be 100% clear, this has nothing to do with the k factor.
I repeat, this is NOT about the k factor.

In short, this is a problem for 3 reasons:
1) It is hidden. Your global ELO gain or loss doesn't add up with you individual ELO gains and loses in a game
2) Even if symmetrical, having a factor that is lower for for players in the "middle of the pack" of a game final standing is NOT fair when the ELO difference between that players is big enough that some of the players are almost bound to be in the upper or middle half of the final result of each game.
3) The factor is currently NOT always symmetrical (see bug report) so that the 1st player and the last player might have a different hidden factor to they ELO change.

The number player factor is the same for everyone, so nothing unfair/assymetrical is going on, just some info from the calculation is hidden.

When you have played 10 games or less the K factor is 60, with 11-20 it is 40. During these stages the number player factor gets lumped in with the K-factor, which is why you see the 27 for K-factor for the 2nd-4th players in your example.