# Chess Ratings - How They Work

• erik
• | Aug 23, 2007
• | 175419 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):

• 6 days ago
Good stuff!
• 13 days ago

The ratings are very important for all the people who claim they aren't. For example, I would rather not waste my time playing someone who is 100+ points below my rating. Playing someone so much lower only hurts my game and had no benefit. The only way to get better is to play someone who is a close match up or someone better. For the guy who asks about tennis players... yes, all tennis players have a world ranking and it is affected by how they play other ranked players. You're ignoring the obvious if you don't want to know your ranking. It is very beneficial to know.

• 3 weeks ago

I think rating sucks. Why? Simple. Are tennis players losing points on the tour when losing a game? Do soccer players losing points in a competition when they lose a game? Or in any other sports? Also i noticed some players increase a lot in rating in one day. So they must cheat. So rating does not say anything about a player, and should not be used in tournements on chess.com. I was put in tournements below 1200 in which i met players who were higher qualified. But it was never corrected. So i think someone should work on this.

• 5 weeks ago

byzzo-SK, it doesn't really make any difference in the long run. If you're playing at a higher level, your rating will increase anyway after you win a few games.

• 5 weeks ago

Dear sir, I just played 2 games with a cheater whom account had been closed after several moves: 15kubo15 Shouldn't I get my winning points regardless of his situation? Kind regards, byzzo-SK

• 6 weeks ago

Sir, Continuing on the same point, may I add that his case is not unique . I found similar anamolies ina few other instances too.

sivacc

• 6 weeks ago

Sir, I am not too concerned about ratings. But recently I played with a gentleman . When out of curiosity ,I looked at his activity , I saw his rating was 1092 and then suddenly 1446 on the same day ! I dont have any issue if he really won so many 'difficult' games, but  would be concerned if the algorithm has a glitch ! I would be happy to share details if you are interested.

sivacc

• 7 weeks ago

Why is it that the best I can do on this chess.com website with a Glicko rating system is about 1850, and yet with a USCF rating I can do about 2220 with the Elo system (at my best)?

• 2 months ago
Yesterday I won a game But my score remained the same .? How was it.?
• 3 months ago

Is the rating used the rating at the conclusion of the game or th start of the game? On turn based of course. I suspect the former. Curious as playing an IM who has just lost 500 points because of time outs. I suspect the 500+ games he's playing at the same time might be the cause!

• 3 months ago

• 3 months ago

jimmyschlitz:

is it better to resign when i am sure to lose, or play to the bitter end? will my rating go down faster if i am check mated more often, or will it go down faster if i resign more often?

I don't think how you lose a game changes the rating value that will change after it, so it basically comes down to "how" you do resign games. If like me you resign when you get no counterplay and something like being one full piece down, your rating will go down faster than if you play until the end, because you would win some of these games (even a tiny percentage of them would affect your rating). When you resign you have no comeback possibility, and as a result, the few games you would win by heavy mistake from your opponent will not go your way. As such, resigning costs you rating points. Now, resigning has the benefit of letting you spend less time on games you don't want to play anymore. This benefit costs you some rating points.

• 5 months ago

why do everyone starts at 1200? does it mean that 1200 is average rating on this web site, or average begginers level on this web site, or how was it determined that 1200 is the right rating to start with?

• 5 months ago

ty

• 5 months ago

I am one of those people who cares less about his rating and simply enjoys playing the game. So for those of you who are discouraged by chess.com's rating system then maybe you should try caring more about the game and less about some silly math formula that uses numbers to determine your "skill". Just food for thought. I find not giving a hoot about those little numbers next to my name allows me to actually enjoy the game at hand rather than racking my brain trying to combat some math formula that I probably couldn't figure out with the help of a super computer.

In short, just the play the game. I bet you'll have more fun then. ;)

• 6 months ago

I agree with Bartcore. Usually, I can't improve unless I've been playing for months nonstop, gaining experience. But when I first start out after a long break, my rating will plummet. It then takes me a good YEAR just to get my rating back up to where it is, and every time I lose a single game I practically have to start over. I've lost almost all motivation to play chess as a result (Note that I haven't had a teacher in about 10 years, and I only ever learned the basics). I haven't played here for about six months, and I only just came back because I was in a tournament taking forever. If you look at any of my games, you can tell I'm screwed already. It's this sort of thing that makes people give up chess.

I kinda wish there was a setting where you could make it so you never see your own rating, or the ratings of others. Just so you could play without that pressure.

• 6 months ago

I find the glicko system to be bad. I have played chess for some time now, staying at a low level. However, last few months I have made drastic improvements. Because of the glicko system, it is going to take years to elevate my rating to a decent level, even though I am already beating 1750 rated players over the board.

I also find that my low rating demotivates me a little.

• 6 months ago

I'm new to chess.com and don't have a rating. I just played my first game against an opponent with a 1400 or so rating. Will i get a rating now?

• 6 months ago

Hi

We wish You pay attention that regressing rating of player

is not that obviouse idea. Think that rating of player accord

his level in chess. His rating must not depend on games's

result because his level is real (i.e. really exists). Allowing

rating to go down we say actually that level of player is virtual.

• 7 months ago

thanx for replying to our chess cares ! important  article