2021 Rating and rank adjustments

maybe 5 - if instead of playing perfect it knows perfectly psychology of opponent and uses trick moves that work only on current opponent.


Perhaps. An omniscient go “devil” who takes advantage of knowing the human’s fears and weaknesses may be able to give more handicap than a properly playing go “god”.


In Fast Correspondence “?” ranked player is placed above anyone else, could be some bug Play Go at online-go.com! | OGS


How well do the new DDK numbers align with AGA and EGF, if we know? It’s mostly curiosity for me, but it would be nice to have some objective-ish idea of “how good am I in general?” Rather than just how good am I relative to the OGS population.


higher than the current EGF ranks, but apparently EGF are going to release a new model soon which should quite closely match what OGS just switched to in the kyu ranks, only diverging in the mid to high dans where these ranks will be easier to achieve on OGS than EGF


Thanks - that makes sense. How well do EGF and AGA ranks line up? (Curious since I’m in the US)

At one point there was actually rating decay over time between games, IIRC. Or was it uncertainty increase over time? Something like that anyhow. Do we still have that, does anyone know?

Also, notably, the X axis is time, not games-played (as it once used to be IIRC). It’d be misleading to show a step function between yesterday and the day before if those two games were actually played just before and after midnight :wink:

Plus in general it’d just look ugly if it were a step function graph between days where you hadn’t played.

So one way or another I can’t imagine there being much interest in changing that :smiley:

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Just wanted to let you guys know I went from 13-14k to 9k, which is pretty much my exact ranking on other servers. I think this new rating system will prove to be excellent.


My 19x19 rating is higher than other sizes. Does that mean if I drop playing 9x9, 13x13, I’ll become stronger :thinking:

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Eugene, I don’t know yet how to block-quote, but I’m not calling for a step function graph between days where you haven’t played. I’m calling for always immediately showing any change in your rating when you finish a rated game. If your rating changes when you are not playing (Does it?) then that would show up too each day. I would be okay if the graph is continuous to connect your rating at the end of each day, but it is silly to prorate your rating change over a month if you are not playing. If your rating changes in one day, your inactivity over the next several days should not blur the fact that your rating changed in that one day.

Question: Does one’s rating change on days without a rated game? If yes, please show these daily changes. Otherwise, I suggest either make a discontinuous graph for each rated-game result, or assemble all of the day’s results and plot ratings at the end of each day.

If you don’t like discontinuities, okay, how about a daily graph? That would be about the same value as a discontinuous graph in my eyes.

I thought you were referring to the curve interpolation between the points, and suggesting it should be discontinuous instead.

That’s what it does though?

Each time you finish a rated game, your rating is updated and the graph updated to reflect it.

However, as I mentioned, the X axis is days, not games, so changes on a given day accumulate in the point for that day - there is only ever one point for day, but it does update with each game.

Personally, I’d rather see the X axis in games, so the rate of change on the graph is in games, not time. I think it was once like that but moved to being X axis is time when Glicko was introduced … because (if indeed I am recalling correctly) rating changes over time.


I think only confidence deteriorates with time, not rating.


Can you recall other reasons why the rating graph went from “games” to “time”?

Not certain, feel like it possibly predated glicko? Think it’s been that way for a while… Possibly just user petition? Both views are valid and subjective.

Nope, it is not. For example, I played games on Sept 18, Sept 22, and Dec 2 (2020). No games in between. The curve is smooth as if I lost rating points every day between Sept 18 and 22, and it is smooth as if I won rating points every day between Sept 22 and Dec 2.

I would rather it showed the result of a day fully on that day. Either make it discontinuous to do that, or connect end-of-day results with connected line segments that display what I’ve gained or lost each day I’ve played. The curve would be constant on days I don’t play.

I would also be fine showing game-by-game results, like you suggested.

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Pro ranks don’t correspond directly to player skill, though. They’re largely honorific, with 9p being awarded in many cases to individuals who win top tournaments or make major contributions to the game. Up and coming lower-rated players are often stronger than their higher rated opponents.

Amateur rankings are more often a direct mapping from some Elo-like value, but even there 9d represents an artificial ceiling. We know that top pros are at least 4 stones or so above that, and current top computers a few stones higher. In Elo-like measurements, the top players are hundreds of rating points above lower-rated 9p players, which simply isn’t reflected in the traditional ranking system.

Even if there’s some asymptotic approach to a top ranking based on handicap, that still isn’t really a skill ceiling, as it’s entirely possible that a better Go playing entity could beat a worse one almost 100% of the time in an even game, but have a worse than 50% record with a 1-stone handicap due to increasingly tight margins of play at the top levels.


once again, what I consider to be the rank ceiling is not the proper “skill ceiling” that would be reached by a perfect player. It is simply the highest possible rank. in fact, 9d used to be reserved specifically for the provably number one best player alive at the time.

I would argue it’s not an artificial ceiling, it is simply the rank of the best (or in this case, the best amateur) players currently playing.

I’m simply arguing that we have 3 different features of the kyu/dan rank system: a top rank, the distance between ranks, and a bottom rank. However, if you have the top rank defined (9d) and the distance between ranks defined (1 stone), then the bottom rank is determined by those two features and the playerbase (in our case 25k was determined to be that rank for our server). If you defined the bottom rank at 30k and made the distance between ranks the same, you might have a different top rank than 9d, 7d, or what have you. If instead you define 9d as the top rank and 30k as the bottom rank, then the distance between the ranks cannot be guaranteed to always be one stone.


I think it’s understood that handicap stones do not provide linear, uniform spacing between ranks at the upper amateur dan levels, nor very beginner kyu levels. It might be more accurate for, say, two stones corresponding to two ranks difference only for a limited range of like 4 dan (?) to 20 kyu (?), maybe. (Which fortunately is helpful for most amateurs.) Beginners don’t know enough about how to use handicap stones, and advanced players use them too well, and the margins of victory are much tighter. This non-linear quality of handicap stones doesn’t mean that there aren’t much wider, measurable skill differences above and below the effective range for handicap stones.

I was more going off some of the stated goals that anoek has mentioned on other forum posts to have ranks line up with 1 stone as much as possible. We have brought up the fact that in olden times dan ranks were separated by half a stone, but that was responded to by stating that that is not quite relevant, and that maybe they should be separated by one stone.

This is actually accounted for in the rating-rank conversion, as the higher ranks require more ELO/glicko score to achieve the same stone rank difference. This is why the conversion uses the natural logarithm to make this conversion.


What happens to the puzzle page now… Are puzzle authors responsible to edit the rank field in their puzzles, or will that happen (or has happened) automatically?