Glicko-1 Calculator

This is a tool which will do an estimate Glicko-1 calculation. It has database lookup functionality into the ACF master ratings list. If you have an ACF rating, just put your name in at the top and the names and results against opponents in the table below. When you are ready, hit Calculate New and an estimated New Rating will be calculated.

Please register and login to access data save a restore features

Your Name :
Your Rating : New Rating :
Your RD : New RD :
Opp Name Rating RD Outcome Delta


28 thoughts on “Glicko-1 Calculator

  1. Pingback: Site replacement complete | Barry's Website

  2. Really love this website and the ease with which you can estimate your new ACF rating (especially with the built in look-up feature.) However, it would be a further improvement if people could also save this as they go throughout the quarter, adding results as games are played instead of having to enter everything in one sitting.

    The new look is fantastic as well. Keep up the great work.

    • Thanks for the feedback Raelene. I’ll give the idea of adding a profile option to the calculator some thought. Even if a user was able to save their input to a .csv file on their computer and have an option to load that back in to the page that would help with this issue.
      Cheers, Barry

      • The new “Save” and “Load” buttons are a fantastic addition to what was already a great site. It’s nice and easy to enter results as you go. Thanks Barry – much appreciated.

        • Yes, the new buttons work well. I have made a glicko1 spreadsheet that I use, so I will see what results I also get by it. Always hard to know what RD to apply for the !!, !, etc rating reliability values, so there may well be some discrepancies. But maybe in future I will just use Barry’s version.

          • One small improvement – would be the software to check that the form has something in it, before saving it. I pressed save when I meant load, and so it worked like the clear form action.

  3. Pingback: Anonymous

    • Go to the main blog page and click on the “register” link on the right hand column.

      Edit: I have also updated the calculator page so that the register and login text strings are hyperlinked.

  4. Barry,

    Love your website and how you constantly implement things to further improve it. Just wondering whether you might be interested in adding another feature to your site – an ACF graph. It would be great to be able to key in a name as it appears in the master list and for a program to generate a rating graph. You may or may not be interested but I think it would be well received and a positive addition to an already fantastic website.

    Kind regards,

    • This sounds like the FIDE ‘rating progress’ thing they do for their per person rating profile, but for ACF ratings. Yes, I like that idea!

  5. May you please add the latest ACF Masterfile to this page? I like using this calculator but inputting the latest ratings and RDs manually is time consuming!

    • I do try to get to this job reasonably soon after new ratings are released. The good news is that December’s ratings are already loaded!!!

  6. This is more of a technical question re the calculation using glicko-1.
    (a) What RD numbers do you use for !!, !, $ etc.
    (b) do you use a cstep1B value of 44
    (c) is your q = LN(10)/400
    I am asking as my implementation of the glicko-1 calc, just using a spreadsheet, is a litle off compared to yours.

    • FYI, I use the numbers in the first column:
      RD is a guess Tornelo RD?
      !! 30 60
      ! 50 95
      blank 100 140
      ? 150 205
      ?? 200 300

    • Hi Scott, In answer to your questions

      (a) I use the numbers in the second column to convert published RD to numerical values. That is I use 60, 95, 140, 205 and 300.

      (b) I use a value of c^2 = 1350. Or in other words c = 36.74…

      (c) Yes, q = log(10)/400 = 0.005756…

      BTW I have a glicko-1 calculator in a spreadsheet which you can download here:

      Cheers, Barry

  7. Hey Barry, excellent feature. I was just wondering how reliable it is? Seems good to me but on chesschat, they said its not “official” which obviously doesn’t mean it’s not accurate.

    • Hi Thomas, I’m the one who made that comment. The algorithm that the ACF uses requires one to know all the other games played in the rating period. As we can’t know this then in principle this page only provides an estimate. However, I’m my experience it is usually only out by a couple of rating points at worst.

  8. Okay, thankyou! Just recommended the website to a few friends to calculate their rating to see if it’d go over 1600 for NSW open so didn’t want to look silly if it was far off ;-)

    What’s the difference between escl, dscl etc

    Thanks for the replu

    • excl, descl is either “!” or “!!” and relates to what is known as the RD. The ACF publishes with along with the rating. So far as what I use as the numerical values for these in the actual calculation, see the discussion above with Scott Humphreys. The ACF keep a particular value for every player but only publishes an indicator (like !!, !, etc). This is another reason this page can only ever be an estimator.

  9. G’day Barry,

    I’m 9 spots of filling up the space.
    It was a very busy month of chess for me, what happens after that? 😁

    • Hope you weren’t too badly affected. It’s a new rating period now so it begins again but if the number of slots is a pain I can easily increase it. I haven’t put the time in to make it dynamic tho’.

  10. Hi Barry,
    This is a great tool. Thanks. Is there a way to get initial ACF rating from this tool for an unrated player?

    • Hi Saminda

      Sorry for the slow response I must have missed the notification and only check this site out closely around new rating time.

      This is quite difficult. If you have all the rated games that the player played you can estimate this by finding the approximate performance rating. One way of doing this is to put in a starting rating of something like 1500 and see what the new estimated rating is. Whatever you get feed that into the calculation as the starting rating and do a new estimate. Keep doing this until the starting and new rating converge to the same rating.

      Note that this will only converge provided the players performance is not 100% or 0%. That is, not all wins or not all losses.

      Hope this helps.

  11. Hi Barry,
    It would be a great help if you could update the web site database with the latest March 2023 ACF ratings. Thank you in advance!

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