Please turn on javascript in your browser to play chess.
Help Forum

Help Forum

  1. Standard member gregoftheweb
    The Great Gonzo
    24 Jun '03 23:35
    First off excellent site, I have four games going and have drawn in both my father in law and a friend.

    My question is this. In general I understand that you gain points for winning matches and lose points for losing.

    Could you please point me towards a detailed explanation of how the points are assigned.

    Thanks
    Greg
  2. 24 Jun '03 23:41
    Hi there. Click on "Help me!" near the top right of your screen, then click on "pop up help files". Number 9 of the FAQ helps to explain what you're after 🙂

    T1000
  3. Standard member gregoftheweb
    The Great Gonzo
    24 Jun '03 23:44
    Thanks. That FAQ should be a top level link IMO.
  4. 24 Jun '03 23:47 / 1 edit
    Just realised that while the above instructions deal with exactly how (ie the formula) for ratings calculation it doesn't really help to explain it in easy to understand terms (not easy for me to understand anyway!).

    At the end of a game the points are decided by the ratings of the two players at the end of the game. If white has a much higher rating than black (eg 200+ points more) then white will receive (and black lose) very few points (since it is "expected" that white would win given the higher rating). If black were to win then white could expect to lose a large number of points (without closely reading through no. 9 of the FAQ I think that the maximum loss/gain regardless of rating is 32 points). Draws work in a similar fashion, but in this instance white would lose a few points and black would gain a few.

    That's pretty brief and off the top of my head so not exhaustive and possibly not 100% accurate.

    T1000
  5. 24 Jun '03 23:48
    Originally posted by gregoftheweb
    Thanks. That FAQ should be a top level link IMO.
    I fink the whole of the help section will be getting an overhaul soon so watch this space....
  6. Subscriber Russ
    RHP Code Monkey
    25 Jun '03 00:01 / 1 edit
    Originally posted by T1000
    I fink the whole of the help section will be getting an overhaul soon so watch this space....
    Lets hope so, in its current state, its nearly useless! 😉

    -Russ
  7. Standard member gotti2000
    The winemaker
    27 Jun '03 21:55
    Originally posted by T1000
    ... I think that the maximum loss/gain regardless of rating is 32 points). ...T1000
    That's correct as long as your rating is lower than 2100.
    If your rating between 2100 and 2399 you may loose not more than 24 points in a game but there is only one person at the moment having that benefit 😵

    If you are one of those who want to find out their potential win/loss in advance you can set up the following in Excel:

    Type your current rating in cell A1 and the opponent's rating in A2

    To calculate your rating in case of a win use the following formula in A3:
    =ROUND(A1+IF(A1<2099;32;IF(A1<2399;24;IF(A1>=2400;16)))*(1-(1/(10^((A2-A1)/400)+1)));0)

    To calculate your rating in case you'll loose use the follwing formula in A4:
    =ROUND(A1-IF(A1<2099;32;IF(A1<2399;24;IF(A1>=2400;16)))*(1-(1/(10^(-(A2-A1)/400)+1)));0)

    For an expected draw us the follwing in A5:
    =(A3+A4)/2

    Gotti
  8. 27 Jun '03 23:06
    Originally posted by gotti2000
    That's correct as long as your rating is lower than 2100.
    If your rating between 2100 and 2399 you may loose not more than 24 points in a game but there is only one person at the moment having that benefit 😵

    If you are one of those who want to find out their potential win/loss in advance you can set up the following in Excel:

    Type your current rat ...[text shortened]... (10^(-(A2-A1)/400)+1)));0)

    For an expected draw us the follwing in A5:
    =(A3+A4)/2

    Gotti
    It doens't with work with me, I fill in (for example) my game against DigitGus wich I am winning: I fill in 1668 in A1 and 1699 in A2, I copy the formula in A3 and press enter...it gives me an error...😕 I use Microsoft Office 2000, so I use Excel 2000.

    Olav
  9. Standard member gotti2000
    The winemaker
    27 Jun '03 23:37 / 4 edits
    Originally posted by LivingLegend
    [b]It doens't with work with me...
    Hmm, I guess the problem is my generic translation, I didn't test this on an English system but only on a German one.
    Well, the key is to change all the semicolons (😉 to colons (,) because the default separator on UK/US systems is the colon as far as I know.
    The following should work for you:
    =ROUND(A1+IF(A1<2099,32,IF(A1<2399,24,IF(A1>=2400,16)))*(1-(1/(10^((A2-A1)/400)+1))),0)

    {To be more precise the separator in your formula must match the 'list separator' setting in the menu Start>Control Panel>Regional Settings>Numbers>list separator (2nd option from bottom)}

    Another issue may be the language EXCEL is using. On my German Excel I have to use RUNDEN instead of ROUND and WENN instead of IF.
    I can't believe that they even translated those keywords into German!

    Anyway if you are using a dutch version you'll find the proper translation. However, if you are using Chinese ... 😲🙄.
    You can get a list of all functions in your language if you hit the function symbol (fx) in Excel which is between the sum symbol and the sort symbol.

    Sorry, hope I didn't confuse you too much. If you've problems let me know.

    gg
  10. Standard member gregoftheweb
    The Great Gonzo
    27 Jun '03 23:51
    I just wrote a quicky little web app to compute the ratings

    http://www7.brinkster.com/obyrne/rhp_rc.htm

    Now I'm not sure if the algorithm is quite right, because according to this tool I should have gotten 29 points for my latest victory and yet I got only 22...hmmm...grand conspiracy.

    I don't want too much traffic over there so if someone wants to bring the little tool in house they can email me at gregoftheweb@hotmail.com.
  11. Standard member gotti2000
    The winemaker
    28 Jun '03 00:06 / 1 edit
    Originally posted by gregoftheweb
    I just wrote a quicky little web app to compute the ratings

    http://www7.brinkster.com/obyrne/rhp_rc.htm
    Thanks for that. It makes life easier in an international environment. Nevertheless, your algorythm seems to be wrong.

    When I use 1200 for MyRating and 1338 for OpponentRating I get 1222 for a win, 1190 for a lost game and 1206 for a draw. Which was the situation when you won against janwenting. Remember the new rating is calculated at the moment you finished the game. In most lists (e.g. Public Games) on RHP they display your current rating not the rating when you finished that particular game.

    You may want to double-check your formula with mine and include that in your tool. It's quite cool!

    Cheers,

    gg
  12. Standard member gregoftheweb
    The Great Gonzo
    28 Jun '03 00:13
    Well I lifted the algorithm directly from the FAQ so if it is different I don't know where to get it.

    View source on the page and look at it.

    g
  13. Standard member gotti2000
    The winemaker
    28 Jun '03 00:42 / 1 edit
    I checked the formula in your code. It's correct as such but something weird happens with the power operator (^) in
    nWinExpectancy = 1 / (10^((nOpponentRate-nMyRate)/400)+1)

    The correct way to do exponential math in java-script is:
    Math.pow(base, exponent)
    You have to change the win expectancy code to following:

    //set win expectancy
    nWinExpectancy = 1 / (Math.pow(10,((nOpponentRate-nMyRate)/400))+1)

    My2cents

    gg
  14. Standard member gregoftheweb
    The Great Gonzo
    30 Jun '03 17:12
    There I go assuming the engine would do what I expected it should. Thanks.