How do ratings work on Chess.com?
Learn how the Glicko system works, including rating deviation and what factors influence your rating changes after each game!
Updated over a week ago
Table of contents
Ratings on Chess.com
Every player on Chess.com has a rating designed to measure their skill level and match them against opponents of similar ability.
You may have noticed that your rating doesn’t always change by the same amount after a win or loss. What causes this variation?
A few factors can affect how much your rating changes after you play a game. These factors include:
The difference in rating between you and your opponent.
How confident we are of your rating.
How confident we are of your opponent’s rating.
Rating change factors
Factor | Details |
Difference in rating | If you win against someone with a much higher rating, your rating will increase more than if you win against someone with a similar or lower rating. Similarly, if you lose against someone with a lower rating, your rating will decrease more than if you lose to someone with a higher rating. |
Confidence in your rating | Our confidence in your rating affects how much your rating changes. High confidence in your rating means smaller changes, while low confidence can result in bigger changes. |
Confidence in your opponent's rating | Just like our confidence in your rating, our confidence in your opponent's rating also influences rating changes. If we are less confident in their rating, the changes to your rating could be more significant. |
Number one is straightforward: the greater the rating disparity between you and your opponent, the larger the potential rating change. Winning against a higher-rated opponent results in a bigger increase, while losing to a lower-rated opponent results in a bigger decrease.
Numbers two and three are more complex but crucial. Confidence in the ratings is a significant reason for substantial changes in your rating after a game.
📰 Check out this article to learn more about how ratings work: Chess Ratings - How They Work
Glicko system
Chess.com uses the Glicko rating system, which includes a measure called ‘rating deviation’ (RD) to indicate our confidence in your rating. If you’re new and haven't played any games, the system is unsure of your 'real' rating, so your rating will fluctuate significantly during your first few games.
If you haven't played in a while, your RD will increase, causing your rating to change more dramatically after your next game. This happens because we can't determine whether you've been practicing elsewhere or haven't played at all.
The same applies to your opponents. If you lose to someone with a much lower rating but a high RD (they haven’t played in a long time), your rating won’t change much since their rating may not be accurate.
💡 As players improve and reach higher levels on Chess.com, the rating changes after each game become smaller.
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In my opinion the ELO system is broken and the ads are bad. I am probably not the first nor will I be the last to post about the ELO system and/or the ads. The ELO system never really gives you plenty of points. As an example, sometimes I might win against someone who is 100 or so ELO points above me and gain only 20 ELO points. Like how does that make any sense? And If I lose to someone who is a 100 or so ELO points below me I lose like 70 ELO points. Now the Ads are something else entirely. Like when Im playing on the mobile app ads will pop up guaranteed. Even when the app is on and Im not doing anything then BOOM there's an ad. Like come on Chess.com can't you please not have ads and fix the ELO system?