Answers.Body: <p>I asked this on ICC once and was directed to the following link:</p>
  
  <p><a href="http://www.chessclub.com/help/ratings" rel="nofollow noreferrer">http://www.chessclub.com/help/ratings</a></p>
  
  <p>IMHO, I don't think there is a fail-safe way to approximate a FIDE rating based on online ratings.</p>
  
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Answers.UserDisplayName: xaisoft
Answers.Body: <p>Online and FIDE ratings can't be directly compared or converted with any real accuracy.  They have a different pool of players and different constraints.  I'd be surprised if the actual mathematical rating method was exactly the same.</p>
  
  <p>The 'pool of players' issue is one of practical import. It turns out, players' geographical isolation highlights an under-appreciated fact about FIDE's rating system.  The FIDE rating system doesn't tell you how good you are; it tells you how good you are <em>compared to other players</em>.  Thus the ratings of isolated groups of players are effectively unrelated.</p>
  
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Answers.Text: This answer is simply incorrect if you look at the data, as other answers have. There is a very strong correlation between online rank on various sites and FIDE rank, and you can even create confidence intervals, ex. 95% CI for chess.com rapid vs FIDE has error bars approx +-270 points.
Answers.UserDisplayName: qwr
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Answers.CreationDate: 2012-06-10T16:37:16.143Z
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Answers.UserDisplayName: Tony Ennis
Answers.Body: <p><a href="https://www.chess.com/member/smarterchess" rel="noreferrer">NM Matt Jensen</a> has done similar research in <a href="https://www.chess.com/article/view/chesscom-rating-comparisons" rel="noreferrer">2014</a>, in <a href="https://www.chess.com/blog/smarterchess/chesscom-rating-comparison-2015" rel="noreferrer">2015</a> and later in <a href="https://www.chess.com/blog/smarterchess/chess-rating-comparison-2016" rel="noreferrer">2016</a> using data from <a href="https://docs.google.com/forms/d/e/1FAIpQLSfCw_Mx0MMSpfYyf7jBqYjPAd5TVEnSEOQbs5xhWezvuqqODg/viewform?c=0&amp;w=1" rel="noreferrer">survey</a> with over 370 surveyees. The survey shows the correlation between <strong>Chess.com</strong>, <strong>Lichess.org</strong>, <strong>USCF</strong> and <strong>FIDE</strong> ratings in Bullet, Blitz and Rapid/Classical categories.</p>
  
  <p>The results can be found on <strong><a href="https://docs.google.com/spreadsheets/d/1GcVG_slcTUJfi0sQMeaxes_jwYFBrfWaR1ejSSOH-SM/edit#gid=0" rel="noreferrer">Google Sheets</a></strong>. Here's the line chart showing the correlation between ratings:</p>
  
  <p><a href="https://i.sstatic.net/mULCH.png" rel="noreferrer"><img src="https://i.sstatic.net/mULCH.png" alt="enter image description here"></a></p>
  
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Answers.Text: How should we interpret that graph? It does not seem to show correlation at all...
Answers.UserDisplayName: Federico Poloni
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Answers.Text: @Federico, if your Chess.com Blitz rating (red curve) were let's say **1200**, you should locate it in the graph and see that it correlates to Lichess.org Blitz rating (purple curve) of approx. **1540** and to FIDE regular rating (lime green curve) of approx. **1280**. The vertical axis represents the ratings and the horizontal axis represents the player.
Answers.UserDisplayName: gdrt
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Answers.Text: @FedericoPoloni: my Lichess classical rating hovers around 1600. Therefore, my projected FIDE rating would be about 1250, a difference of 350 points. To see this, follow the Lichess classical curve to its extreme left, which happens to rate 1600; and then drop straight downward 350 points to find the FIDE curve.
Answers.UserDisplayName: thb
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Answers.Text: I'm not sure we use the word [correlation](https://en.wikipedia.org/wiki/Correlation_and_dependence) in the same way; I was expecting a coefficient between 0 and 1.
Answers.UserDisplayName: Federico Poloni
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Answers.Text: @FedericoPoloni you are thinking of a correlation coefficient. Correlation, as stated in your link, is broadly any statistical relationship, especially a linear relation. This is shown in the graph.
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Answers.UserDisplayName: gdrt
Answers.Body: <p>I took the raw data from the source linked to by gdrt and looked at some pairwise correlations, but not all. There are too many pairs to consider and not enough data for most of them, so I focused on chess.com blitz ratings vs classical FIDE/USCF ratings, which were the most abundant. I also looked at chess.com vs lichess blitz. You can find them at this <a href="https://docs.google.com/spreadsheets/d/1P31eoZ5ziMdzq3Hqz9mg6CcRRHRm-XM7wvJlxjwB2MM/edit#gid=901214141" rel="nofollow noreferrer">Google sheet</a>.</p>
  
  <p>In general there is clear correlation between the ratings, with r<sup>2</sup> 0.7-0.8, but the standard deviation of the residuals is about 200. That means that to have a 95% confidence on a prediction obtained from the regression model, the error bar is roughly +/- 400! (Two standard deviations.) The correlation between chess.com and lichess blitz is slightly better.</p>
  
  <p>You can find all the equations in the link above, but since the original question was specifically about predicting FIDE rating from chess.com, I'll also post that one here:</p>
  
  <pre><code>fide = 0.7360*chess.com + 458
  </code></pre>
  
  <p>Again, this is classic FIDE vs chess.com blitz, and the error bar is about 400 points so don't expect a very accurate estimate!</p>
  
  <p><a href="https://i.sstatic.net/V0lCV.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/V0lCV.png" alt="FIDE vs chess.com correlation"></a></p>
  
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Answers.Text: Brilliant analysis! Could you do the equations for rapid/classical as well? :)
Answers.UserDisplayName: gdrt
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Answers.Text: This is embarrassing: I completely misinterpreted the spreadsheet! It turns out that the "comparisons" tab which I used to derive the equations above is already a model, not the raw data, which is in another tab. That explains the suspiciously good fit! I'll update my answer later, but just to give an example, the correlation between chess.com blitz and FIDE regular has an r^2 of 0.75.
Answers.UserDisplayName: itub
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Answers.Text: I also overlooked that you used the model labels for your analysis. Hence the perfect residual sum of squares of 0.
Answers.UserDisplayName: gdrt
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Answers.Text: @gdrt, I completely rewrote my answer based on the raw data instead of the comparisons tab. I don't think there is enough data to say much about online rapid/classical or about offline rapid/blitz (well, maybe there is enough chess.com rapid but I got tired... :-) )
Answers.UserDisplayName: itub
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Answers.UserDisplayName: itub
Answers.Body: <p>This is roughly the conversion for different sites. CC stands for Chess.com, and Li stands for LiChess.</p>
  
  <p>1000 FIDE->1200 USCF->1100 CCBlitz->1250 CCRapid->1450 LiBlitz->1500 LiClassic</p>
  
  <p>1200 FIDE->1350 USCF->1300 CCBlitz->1450 CCRapid->1600 LiBlitz->1700 LiClassic</p>
  
  <p>1400 FIDE->1500 USCF->1450 CCBlitz->1600 CCRapid->1725 LiBlitz->1850 LiClassic</p>
  
  <p>1600 FIDE->1700 USCF->1600 CCBlitz->1725 CCRapid->1850 LiBlitz->2000 LiClassic</p>
  
  <p>1800 FIDE->1900 USCF->1850 CCBlitz->1825 CCRapid->2050 LiBlitz->2150 LiClassic</p>
  
  <p>2000 FIDE->2075 USCF->2050 CCBlitz->1900 CCRapid->2200 LiBlitz->2250 LiClassic</p>
  
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Answers.CreationDate: 2018-07-05T17:35:24.733Z
Answers.Text: Do you have a source for this?
Answers.UserDisplayName: Herb
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Answers.UserDisplayName: Ryan Pittel
Body: <p>I'm wondering if there's any way to get an approximation of my FIDE rating by using one of my online ratings, say ICC or chess.com rating? If not, is there, at least, a correlation between how well you rank on those sites and your eventual FIDE rank?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-05-17T11:47:36.443Z
Comments.Text: Just answering the title: the correlation is positive.
Comments.UserDisplayName: Evargalo
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-09-28T23:12:43.457Z
Comments.Text: It really varies depending on the online site. But online rating is usually quite a bit higher.
Comments.UserDisplayName: Inertial Ignorance
Tags: <rating><online-chess><fide>
Title: What's the correlation between FIDE rating and online rating?
ThreadText: # What's the correlation between FIDE rating and online rating?
  
  (Asked by: username_0 on 2012-05-03)
  
  I'm wondering if there's any way to get an approximation of my FIDE rating by using one of my online ratings, say ICC or chess.com rating? If not, is there, at least, a correlation between how well you rank on those sites and your eventual FIDE rank?
  
  **Tags:** rating, online-chess, fide
  
  > **Comments:**
  > **username_1**: Just answering the title: the correlation is positive.  
  > **username_2**: It really varies depending on the online site. But online rating is usually quite a bit higher.  
  
  ---
  
  ## 5 answers
  
  ### Answer by username_3 on 2012-05-03. Score: 9 | Accepted answer
  
  I asked this on ICC once and was directed to the following link:
  
  <http://www.chessclub.com/help/ratings>
  
  IMHO, I don't think there is a fail-safe way to approximate a FIDE rating based on online ratings.
  
  
  ---
  
  ### Answer by username_4 on 2012-06-10. Score: 8
  
  Online and FIDE ratings can't be directly compared or converted with any real accuracy. They have a different pool of players and different constraints. I'd be surprised if the actual mathematical rating method was exactly the same.
  
  The 'pool of players' issue is one of practical import. It turns out, players' geographical isolation highlights an under-appreciated fact about FIDE's rating system. The FIDE rating system doesn't tell you how good you are; it tells you how good you are *compared to other players*. Thus the ratings of isolated groups of players are effectively unrelated.
  
  > **Comments:**
  > **username_5**: This answer is simply incorrect if you look at the data, as other answers have. There is a very strong correlation between online rank on various sites and FIDE rank, and you can even create confidence intervals, ex. 95% CI for chess.com rapid vs FIDE has error bars approx +-270 points.  
  
  ---
  
  ### Answer by username_6 on 2018-05-17. Score: 7
  
  [NM Matt Jensen](https://www.chess.com/member/smarterchess) has done similar research in [2014](https://www.chess.com/article/view/chesscom-rating-comparisons), in [2015](https://www.chess.com/blog/smarterchess/chesscom-rating-comparison-2015) and later in [2016](https://www.chess.com/blog/smarterchess/chess-rating-comparison-2016) using data from [survey](https://docs.google.com/forms/d/e/1FAIpQLSfCw_Mx0MMSpfYyf7jBqYjPAd5TVEnSEOQbs5xhWezvuqqODg/viewform?c=0&w=1) with over 370 surveyees. The survey shows the correlation between **Chess.com**, **Lichess.org**, **USCF** and **FIDE** ratings in Bullet, Blitz and Rapid/Classical categories.
  
  The results can be found on **[Google Sheets](https://docs.google.com/spreadsheets/d/1GcVG_slcTUJfi0sQMeaxes_jwYFBrfWaR1ejSSOH-SM/edit#gid=0)**. Here's the line chart showing the correlation between ratings:
  
  [![enter image description here](https://i.sstatic.net/mULCH.png)](https://i.sstatic.net/mULCH.png)
  
  > **Comments:**
  > **username_7**: How should we interpret that graph? It does not seem to show correlation at all...  
  > **username_6**: @Federico, if your Chess.com Blitz rating (red curve) were let's say **1200**, you should locate it in the graph and see that it correlates to Lichess.org Blitz rating (purple curve) of approx. **1540** and to FIDE regular rating (lime green curve) of approx. **1280**. The vertical axis represents the ratings and the horizontal axis represents the player.  
  > **username_8**: @FedericoPoloni: my Lichess classical rating hovers around 1600. Therefore, my projected FIDE rating would be about 1250, a difference of 350 points. To see this, follow the Lichess classical curve to its extreme left, which happens to rate 1600; and then drop straight downward 350 points to find the FIDE curve.  
  > **username_7**: I'm not sure we use the word [correlation](https://en.wikipedia.org/wiki/Correlation_and_dependence) in the same way; I was expecting a coefficient between 0 and 1.  
  > **username_5**: @FedericoPoloni you are thinking of a correlation coefficient. Correlation, as stated in your link, is broadly any statistical relationship, especially a linear relation. This is shown in the graph.  
  
  ---
  
  ### Answer by username_9 on 2018-05-17. Score: 4
  
  I took the raw data from the source linked to by username_6 and looked at some pairwise correlations, but not all. There are too many pairs to consider and not enough data for most of them, so I focused on chess.com blitz ratings vs classical FIDE/USCF ratings, which were the most abundant. I also looked at chess.com vs lichess blitz. You can find them at this Google sheet.
  In general there is clear correlation between the ratings, with r2 0.7-0.8, but the standard deviation of the residuals is about 200. That means that to have a 95% confidence on a prediction obtained from the regression model, the error bar is roughly +/- 400! (Two standard deviations.) The correlation between chess.com and lichess blitz is slightly better.
  You can find all the equations in the link above, but since the original question was specifically about predicting FIDE rating from chess.com, I'll also post that one here:
  fide = 0.7360*chess.com + 458
  
  Again, this is classic FIDE vs chess.com blitz, and the error bar is about 400 points so don't expect a very accurate estimate!
  
  > **Comments:**
  > **username_6**: Brilliant analysis! Could you do the equations for rapid/classical as well? :)  
  > **username_9**: This is embarrassing: I completely misinterpreted the spreadsheet! It turns out that the "comparisons" tab which I used to derive the equations above is already a model, not the raw data, which is in another tab. That explains the suspiciously good fit! I'll update my answer later, but just to give an example, the correlation between chess.com blitz and FIDE regular has an r^2 of 0.75.  
  > **username_6**: I also overlooked that you used the model labels for your analysis. Hence the perfect residual sum of squares of 0.  
  > **username_9**: @username_6, I completely rewrote my answer based on the raw data instead of the comparisons tab. I don't think there is enough data to say much about online rapid/classical or about offline rapid/blitz (well, maybe there is enough chess.com rapid but I got tired... :-) )  
  
  ---
  
  ### Answer by username_10 on 2018-07-05. Score: 1
  
  This is roughly the conversion for different sites. CC stands for Chess.com, and Li stands for LiChess.
  
  1000 FIDE->1200 USCF->1100 CCBlitz->1250 CCRapid->1450 LiBlitz->1500 LiClassic
  
  1200 FIDE->1350 USCF->1300 CCBlitz->1450 CCRapid->1600 LiBlitz->1700 LiClassic
  
  1400 FIDE->1500 USCF->1450 CCBlitz->1600 CCRapid->1725 LiBlitz->1850 LiClassic
  
  1600 FIDE->1700 USCF->1600 CCBlitz->1725 CCRapid->1850 LiBlitz->2000 LiClassic
  
  1800 FIDE->1900 USCF->1850 CCBlitz->1825 CCRapid->2050 LiBlitz->2150 LiClassic
  
  2000 FIDE->2075 USCF->2050 CCBlitz->1900 CCRapid->2200 LiBlitz->2250 LiClassic
  
  > **Comments:**
  > **username_11**: Do you have a source for this?  
  
  ---
  
  