# Chess Ratings - How They Work

• erik
• | Aug 23, 2007
• | 117874 views

Like it or not, we ALL have a chess rating. You may not care at all about your rating, or you may be whining every time it goes down in the slightest. You might be someone who plays a game a year, or someone who plays 1,000 a day. Still, there is a number out there that represents how well you play chess. Well, that's the theory, anyway.

To understand chess ratings you have to understand two things: #1 - that you have a TRUE rating that perfectly represents your strength of play, and #2 - that that TRUE rating will never be known and so we have to use statistics to get as close as possible to the truth. I'm writing this article in response to many people who ask about ratings and need a simple explanation of how they work. (I only know about all this because of a recent super-in-depth statistics course I took and my research in building Chess.com!)

There are two main rating systems, and each one has its merits.

The Elo System (used by the United States Chess Federation, FIDE, and many other online chess sites) is popular for two reason - it has been around for a long time, and it is simple. The idea is this: given two chess players of different strengths, we should be able to calculate the % chance that the better player will win the game. For example, Garry Kasparov has ~100% chance of beating my 4-year-old daughter. But he may only have a ~60% chance of beating another Grandmaster. So when playing that other Grandmaster, if he wins 6 games out of 10, his rating would stay the same. If he won 7 or more, it would go up, and 5 of less, his rating would go down. Basically, the wider the spread of the ratings, the higher percentage of games the higher rated player is expected to win. So to calculate a person's rating after playing a few games you calculate the average ratings of his opponents, and then how many games he was expected to win, and then plug it into a formula that spits out the new rating. Simple enough. Well, it turns out, that is maybe TOO simple.

I wish there was some simple analogy to explain all this, but there isn't. It all comes back to this: you have a theoretically exact chess rating at any given moment, but we don't know what that is and so we have to use math to estimate what it is. There are really smart people out there who work on this stuff for a living, and at the end of it all we get to put their proven methods into our code so that we can all enjoy knowing what little numbers next to our name we deserve.

If you want to read more, check out these articles (WARNING - SEVERE NERD CONTENT AHEAD):

• 2 years ago

I am glad that I rediscovered you! It's been a long time and I have been playing a (little) chess on  Pogo.com. They don't have problems initiating a game when my opponent plays the white pieces. You do, in all due respect. I am waiting for my opponent to make his move with the white pieces. Why haven't you set up things in a working manner here that will notify him that I have started a game using the black pieces, and have to wait for him to make his, i.e. the first move? What is the matter here? Today is February 25, 2012. I await you quite necessary reply, after you repair the problem, please.

• 2 years ago

ssdeep u played with an opponentof lower rating! that's reason for droping down of ur current rating.

• 2 years ago

Thank you for the explanation.

• 2 years ago

hi dear popskirk ! please take into account the number of opponent pieces u have knocked down and their value in total !! this may go to help u to find out the accuracy of the points number  U earned!!

• 2 years ago

Veeeery interesting! I will not read the long version of how your rating system works,but it seems to work OK as far as I'm concerned.

• 2 years ago

Help! Just joined  awhile ago ...I played in Blitz game and wins 4 so far :p   Please, can anyone tell me why it says on the top left corner says "Standard". Isn't it should be "Blitz" ?  And why my Online rating is Unrated....(well, i never win yet :p ) ..but is there any setting that i should  do?..I didn't really filled up the  settings when i started the game .What does it mean by Max.of games, Opponent rating (min-max) , Time per move?. Do i really have to filled it up? or not really..

Thank you, I'll appreciate it if you can help me.xxx

nen407

• 2 years ago

hi Fozor! Thanks for your query!! Your needed solution is already posted by Blackenne , US.Please look on the previous posting preceding yours query!!

• 2 years ago

hi French Fozor, please click on the name tab of your opponent on the chess board top corner and then his ratings will come up to your notice!!

• 2 years ago
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• 2 years ago

Query:

Have been challenged to a tournament. Haven't "archived" it so lost in some Martian orbit.

How do I :

a) contact player (named MarijaSM) controlling tourney?

b) How are these tournaments controlled? Do I play x players in a set time (eg: 3 months)?

c) How do I find previous message/challenge sent to me?

Am so enjoying the games.

Thank you, e~

• 2 years ago

I have a question,

Will timeout affect the rating?

• 2 years ago

why some people doesn't dropped there rating while they resign. While I did same and lost my rating

• 2 years ago

In tactical trainer I've got some offers... Imho, average time of some problems the inadequate... I have offers how correctly to calculate "average time", it should give more realistic picture of ratings! I suggest to calculate not average size, and the most probable. I.e. I mean to assume that distribution of intervals of the decision rather the most probable size is normal (Gaussian)! In that case the expected estimation on time should be very plausible. Influence of casual deviations isn't enough and consequently the new average won't flounder there-here. And also intervals of repeated decisions shouldn't get to statistics of intervals, after all abundantly clear that if the person solves the second time the same problem it will spend much less time. After all, really, whether to create something new, whether to go on the blazed way...

• 2 years ago

I noticed something rather strange, and am wondering whether this is expected in the Glicko rating system. Consider these three consecutive turn-based games, dated just a couple days apart:

 RonnieBurton(1359) reesmf (750) 1-0 (won) 10 days 20 5/27/2008 view reesmf (783) RonnieBurton(1326) 0-1 (won) 10 days 31 5/23/2008 view RonnieBurton(1326) reesmf (783) 1-0 (won) 10 days 34 5/18/2008 view

None of these are marked as unrated, so presumably they were rated. How is it possible that the win on 5/23 results in no change in the players' ratings, and the one on 5/27 does?

Another puzzling occurrence:

 NatalieKleffman(1316) reesmf (1284) 0-1 (won) 10 days 21 6/05/2008 view RonnieBurton (1359) reesmf (750) 1-0 (lost) 10 days 20 5/27/2008 view

Looking at the past history of the Black, you can see that his win was preceded by 21 losses (all to the player that was rated 1326 most of the time), 1 draw (same player), and one win against a 768-rated player. None of the games are tagged as unrated.

Now a single win produces rating gain of 534 points.

Is such a gain normal and expected in the Glicko system?

Just curious.

• 2 years ago

i agree with mr. ozfamilyman.. i am playing 100s of games in my vacation and keep me away at times.. i dont win many games, but i am happy to play with everyone who come across, without checking their rating.. some people abort games when they see someone with lower rates, coz, may b they r afraid of losing to them which may result in heavy drop in ratings.. such people kill the spirit of game. if they r not confident enaf to play with everyone, or r afraid of losing ratings and feels gud at living with these high points gained thru filtering, they r unaware of the original spirit of life...

• 2 years ago

Hi mrkoolarana of USA !! I see you joined with Chess.com in July last  and was wondering how & with whom to play with  and fit in !! I saw your query to-day !! May be its a bit late and by this time you got your self fit in and found mates to play with chess !!! and enjoying. Needless to say again that it was very easy to fit in with the game set up by selecting your option from the games menue which is instantly presented  when logged in. If you are still in problem ,please ventilate here or in Forum for general discussion.

• 2 years ago

ssdeep: "i am new to the online chess  turn based chess in this site,so far i won 7 games on a trot albeit with lower rated players,for the first six games my rating peaked to 1622 then even after winning the 7th on it suddenly dropped to 1422?!,and the 7th game was won against a 1300+ player,most of the games i played wer part of some tournament where i cannot decide who my opponent is."

Hey ssdeep, your 7th game was a chess960, it have a seperate rating, so it did increase to 1422.

• 2 years ago

Hi  dear Lorraine219,Manchester UK. You can do it at the begining. Before you start the game you click on the game options menu selecting "Rated". Thats all!!

• 2 years ago

Hi...

• 3 years ago

Just click on the opponents name , it will appear !!