FFA - ELO and and things related.

quote: I recall some years ago we had a FFA ladder, it was quickly removed and we reverted to casual\MM ladders....

There was never a proper FFA ladder - but there was a thread in which DeinFreund ran rating calculations for FFA (among other interesting queries like nemesis players, synergies and antisynergies, etc) - all based on a scraped dataset.

It was not "removed", it's just that then Dein stopped doing it. Cuz, you know. Lots of manual work.

quote: I only bring this up because there are a few arguments for FFA ladder recently, a main one being the disparity of it with teams and MM...

IIRC the previous discussion more or less converged on that making all FFA unranked would be a quick and easy thing to do. But it's touching infra, so that's unfortunately slow.

quote: Idk, thought this may worth revisiting.

The optimal way to revisit this would likely be with a pull request. :P

I would express the second argument more along the lines of "some players may be motivated to throw or collude in FFA games to tank or otherwise manipulate casual rating".

For a single person trying to tank their rating, or multiple people manipulating their rankings in public rooms, deliberately losing 1v1 or team games is more obvious than deliberately losing FFAs, and the admins would likely do something about it eventually (this has happened once or twice). I think it would be fairly easy to throw in FFA games while doing nothing that was actionable.

A group of people manipulating their ratings in ranked private games is zero-sum. For one person or team to win the other always loses. A group of people colluding in FFA can probably increase the average winrate of everybody in the group at the expense of everybody else in the game.