The constants are set up here such that most players have an RD near or above 100.  If that is how chess.com wants it to be, then there is no problem.

How do you "want" a particular value of a constant - it's not like a flavour of ice cream.

What, surely, we all want is the value of constants that gives the best rating system. If RDs go too high, you get too much fluctuation around your true strength. If they go too low, there is not enough movement to reflect a genuine improvment. So there is a delicate balance to strike.

My impression is that RDs are too high and there is too much fluctuation. But it ought to be possible to do some reasonably advanced diagnostics on how well the ratings predict the results of games, to fine tune the constants.

Yes, and since the average RD on this site 130 (see the thread about inflated ratings for the link to chess.com page that shows the average players' stats) and achieving a low RD requires that you play hundreds of simulataneous games, high fluctuation is something we must all deal with on this site.  The admins of this site have so far been unwilling to have a debate on this subject.  In the thread about inflated ratings a staff member commented once or twice and then abruptly dropped out of the conversation as soon as my link showing the average RD of chess.com players appeared.

Strange. To go to all the effort of using a Rolls Royce system like Glicko, and not tweaking the constants to get the best results. It's like using a Ferrari to pull a caravan. 

Just wanted to add that I have since come around in my thinking and now agree fully that this system is not a good fit.

How about this: a guy doesn't play here for over a year and his Glicko goes over 320. He wins a game against a higher rated opponent and his rating goes up by more than 500 points. Doesn't that sound ridiculous?
Even if you think that an average Glicko of 130 is OK, it seems to me that the Glicko of a "returning" player should not be as high as a player who is just starting on chess.com....

 Is it ridiculous? In order to get that big a shift, he would have to beat someone over 400 points higher than he is (and someone with a low RD). Isn't that evidence that in the past year he has learned enough to improve his rating by that much? If he has learned that much, he deserves the rating boost. If he hasn't learned that much, he'll lose the ratings boost when he loses the next couple games against similarly rated opponents.

 Your RD is 109..

The lowest i'v seen on this site is 46 so far..

I agree though.. Ouachita is 150 RD.. thats ridiculous.. no wonder hes so high in rating.. (but then he can drop REALLY low... even a draw insures him to drop over 70 rating)

They should lower the RD for every1.. so new comers RD's a bit lower then it should be and every1 elses is lower then it should be etc..

i'm not opposed to tweaking the RD settings some. i am currently at RD 81. i play a lot of chess here (obviously). what should my RD be? what would be more fair in your opinion?

here is my current rating graph of 1 year:

does that fluctuate too much? i dunno. i know that my actual SKILL doesn't change that much, but i know that the amount of effort i put into my games, and the amount of stress i feel, does fluctuate that much. plus, i know i have gotten a lot better with all of the study and play that i do.

personally i am not a ratings watcher. i don't care about my rating as anything more than a rough indicator. perhaps that is reflected in our loose RD. maybe we should tigthen it up. but with ratings you can never win :) people want their ratings to go up faster, and down more slowly. right now we get some complaints of people's ratings dropping too much, but we never get complaints about them rising :) if we change it, we might start getting more complaints. i dunno.

we've also complemplated shaving 100 points off of everyone's rating and making the starting rating 1000. but if we do that, and we lower the RD... how many games before an 1800 rated player is accurately rated?

Well, if you shaved everyone's rating by 100 points, the 1800 would be as accurately rated as they were before the shave, because the ratings are relative. If you dropped the starting rating by 200 at the same time, that would merely mess up the old player's ratings relative to the new player's ratings. I have no idea how long that would take to balance out. It would depend on the rate of new players coming in and the number of games per rating period. I could try to run some simulations on that.

I haven't thought about the ratings deviations as much, so I'm not sure of the effects of lowering everyone's RD. I have been wondering about the length of the ratings period compared to the typical rate of play here. If the ratings period is a day, but I'm only finishing a game every two or three days, my RD is going to keep floating up because of the periods where I don't have a completed game. If the rating period is a week then that's not a factor. 

erik, I think the problem is not people whining about their ratings going down, but quite simply the question of accuracy.

It's great having tournaments for 1400-1600 players, etc, but if the ratings are unnecessarily inaccurate, this is undermined.

You're right that effort varies greatly, and this suggests a higher RD than would otherwise be best. My guess is that it is too high even for that.

Can I suggest an experiment. Calculate what everybody's ratings would be today if the RD increased, say, 5 times more slowly. And see if those ratings more accurately predict match results than the current ratings do.

I'm beginning to change my mind on this topic.

My last 10 games:

Average opponent rating: 1927. Results: 8 wins, 2 draws

Starting rating = 2468. Current rating = 2424

I lost 103 points from my 2 draws (against opponents rated 2015 and 1813), but because they were my first results in a while, my RD had increased significantly. My wins all came in quick succession, so my RD kept falling, making each win worth less. It seems a bit tough that with this record I've actually dropped 44 ratings points overall. It looks like I'm going to draw another couple of games against 2000-2100 players, so my rating is going to take another hammering.

Conclusion: I think the constant for calculating the RD should be reduced for turn-based chess. I'll no doubt change my mind when the current system works in my favour...

@jonnyjupiter: A 2468 in a ten game match with a 1927 has an expected score of 9.5. Therefore 8 wins and 2 draws is a slight underperformance (just based on the average), and a slight ratings drop is reasonable.

ok - looking for INTELLIGENT replies to this topic:

http://www.chess.com/forum/view/community/math-people-only-changes-to-how-much-ratings-change

basically, i think that a target RD for someone who plays a LOT of chess on Chess.com should be 30-50. i play quite a bit and i'm 81.

come give your opinion!

Thanks for that - it does help me to understand it. I did feel that I was playing poorly for one of the draws, so if I had won that my rating would have stayed pretty much at a level.

Fair enough then - I underperformed and thus my rating dropped appropriately. Hey ho.

I play very much, can anyone please tell me what's my RD? I guess about 70.

Here u go mate! :-)

What a good guess from me!

Hahaha Yes, very good guess indeed!

Maybe it would be even better if asked a bit earlier :)