Rank system and 9x9 handicaps problem

Why u quoting me? You could quote you :joy:

of user that already has rank

I interpret those issues more as bug fixes, tweaks and finetuning than a rating system overhaul.

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Are there any properties of the system we would jeopardize by doing ad-hoc fixes (cutoffs, counterweights)?

I do think itā€™s cool we can update the rank from these extreme games, but yeah, linear loss function sounds like it ought to be better.

Clicking on a few of the games, it looks like the user was using auto-handicap. In that case, once the user was winning more than 50% of the games, Iā€™d expect the rank difference between the user and the bot to stabilize. Instead the userā€™s rank kept dropping (increasing rank difference) even once they started to win more than 50%.

For example, in the last couple of games the user has a handicap rank difference of 16, and the observed rank difference between user and bot is 16. This should result in symmetry between the increase/decrease of the userā€™s rank after a win/loss. But thatā€™s not what happens. A loss triggers a bigger change than a win does.

I donā€™t have easy access to a computer right now to look deeper. But I wonder if there is a bug causing this asymmetry.

Speculatively, maybe the effective handicap for the ratings update is somehow capped at 9 after a win, but not capped at all after a loss.

Or, there could be other explanations.

I wonder what the rating calculator would say for this series of games, plugging in the ā€œhandicap rank differenceā€ from game info for the handicap.

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I agree in principle with @Uberdude, but want to note that extreme or strange handicaps have more chance of hitting the case where the system evaluates the effective rank difference as 50:50 win rate, but for a particular pair of players the win rate is 9:1. Maybe one of the players has a lot of experience with this kind of handicap and the other has none. (This is why I think for rating v6 it might be useful to increase the uncertainty for larger (or stranger) handicapsā€¦ effectively decreasing the increase/decrease after a win/loss.)

Regardless, Iā€™d expect a player doing auto-handicap against a bot to have their rank stabilize to a place where they are winning 50% of the games. If thatā€™s not happening then thereā€™s something a bit funny going on with the ratings updates. Maybe they just need to play a bunch more games for it to stabilize, but in the case cited above the final page of games/ratings looks a bit off to me.

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