EGF Official ratings system


Downloads General info System description Remarks How to submit results References


Downloads:

These plain text files are updated in real-time. You can download them for any purpose you need.
By the way, they are strictly compatible with those provided by old rating pages.


National rating ladders

(real time update)

  (tick here if you want to include the R_max column, which shows the highest rating achieved by the player over the last 12 months)
AD - AndorraAM - ArmeniaAT - AustriaAZ - AzerbaijanBA - Bosnia
BE - BelgiumBG - BulgariaBY - BelarusCH - SwitzerlandCY - Cyprus
CZ - CzechiaDE - GermanyDK - DenmarkEE - EstoniaES - Spain
FI - FinlandFR - FranceGF - French GuianaGR - GreeceHR - Croatia
HU - HungaryIE - IrelandIL - IsraelIS - IcelandIT - Italy
KZ - KazakhstanLT - LithuaniaLU - LuxemburgLV - LatviaMD - Moldova
MK - MacedoniaNL - NetherlandsNO - NorwayPL - PolandPT - Portugal
RO - RomaniaRS - Republic of SerbiaRU - RussiaSE - SwedenSI - Slovenia
SK - SlovakiaSM - San MarinoTR - TurkeyUA - UkraineUK - United Kingdom
YU - YugoslaviaAll European players   


Other rating files download

(real time update)

File Description TXT / HTML ZIP
alleuro_lp List of all European players who ever participated in any included tournament 2.9 MB 843 KB
allworld_lp List of all World players who ever participated in any included tournament 3.1 MB 905 KB
all.hst Complete history of rating development of all players (one row for each tournament) 29 MB 4.3 MB
tlist List of all included tournaments ( 2011-02-16: the file format has slightly changed; now it reports also number of rounds and number of players for each tournament ) 585 KB 135 KB


General Information

The rating system was adopted by Czech Go Association at the beginning of 1998. Originally it was designed to serve only the needs of Czech go community. Later on we decided to enlarge the tournament database by including other European tournaments and made it comparable with the former EGF database. The system has been used for computing the official EGF ratings since November 1998. The included events should meet following conditions:
  • The event took place not earlier than January 1, 1996.
  • The tournament is recognized as EGF classified event.
  • Both handicap and even games are accepted.
Fast games (less than 30 minutes) are not counted because their results are less consistent. We allow for handicap games since their inclusion helps to keep the correspondence between ratings and grades. At the same time it also enables to follow the commonly accepted requirement on the number of handicap stones to be used in a game between opponents of different strength if both players should have the same chance of winning. We would be glad if you could send us any tournament table meeting the specified conditions and not included so far. If you do so, please, try to follow our instructions for sending the tournament results.

The rating list includes all "European" players who participated at tournaments that are in the database. An average 1 dan should have Go Rating about 2100 and the difference between grades is set to 100 (6 dan = 2600, 1 kyu = 2000, 20 kyu = 100 etc.). These values are also used to initialize the rating of a new player. The scale of professional grades is set provisionally to 1p = 7d = 2700, 2p = 2730, ... , 9p = 2940. If player's rating drops below 100, it is reset to GoR=100 which is fixed as the bottom value.

Example 1: The ratings of top European amateur players Guo Juan and Lee Hyuk fall in the region of 3p-4p.

Example 2: The player with GoR = 2050 can be regarded as either a weak 1d or a strong 1k.

Depending on players' tournament results and on the various ranking systems used in different countries, the correspondence between grades and GoR may not work quite well especially for lower kyu grades. However, it gives a relatively good measure of player's strength provided that he/she has participated in at least 3-5 tournaments.

If a player has not participated at any considered tournament for some time (this period is set to 2 years for dan players, 12 months for 1-10 kyu, and 6 months for 11-20 kyu; the actual year/month is not counted), he/she drops out from the current rating list. However, the player's rating is kept in the database of players and it is used once he/she appears again at any tournament in the future.



System description

The rating system is derived from ELO rating system used by International Chess Federation (FIDE). It is based on the idea that one can define a probability of winning a game (so called winning expectancy SE) depending on the difference of opponents ratings D=RB-RA. For the player with lower rating (let us call him "player A") the quantity is given by

(1)      SE(A) = 1 / [eD/a + 1] - ε/2

The winning expectancy of his higher (or evenly) ranked opponent ("player B") is obtained from the equation

(2)      SE(A) + SE(B) = 1 - ε

If ε=0, Eq.(2) simply states that the sum of both winning expectancies should be normalized to one. However, such setting suffers from long term deflation as the new improving players take points from already established players. This is countered by various instruments like an existence of rating bottom, winning expectancy setting, rating resets in some specific cases and finally by introduction of a small parameter ε > 0.
At the moment, we use ε=0.016, a value fitted to balance rating variations in dan region. Although such small value has negligible effect on variation of player's rating at one tournament, the parameter ε allows to tune the long term system behaviour in a desired way.

A typical behaviour of SE is shown in Table I where the quantity was calculated with the parameters fixed at the values: a=115, ε=0. This setting gives about 30% probability for beating a 1 grade stronger opponent. Since stronger players play more consistently than the weaker ones, the probability of beating a 1 grade weaker opponent tends to rise with player's grade. This fact is reflected in our system by an appropriate dependence of parameter a on the rating value of player A. The complete setting is shown in Table II where the corresponding probabilities of beating a 1 grade stronger opponent are given as well. As one can see, 20 kyu is expected to win about 40% games with one grade stronger opponent while the top amateur players should win only 20% of their games with 100 rating points stronger opponents.

Table I: Winning expectancies SE for some selected rating differences D calculated with a=115, ε=0.
D 20 40 60 80 100 120 140 160 180 200 300 400
SE(D) 0.4570.4140.3720.333 0.2950.2600.2280.199 0.1730.1490.0690.030


In a single even game the rating of a player changes by

(3)      Rnew - Rold = con * [ SA - SE(D)]

where SA is the achieved result (SA = 1, 0 or 0.5 in case of jigo) and the factor con characterizes the magnitude of the change. In our system the parameter con is a decreasing function of player's rating specified in Table II.

Table II: The dependence of parameters con and a on the rating. For convenience the winning expectancies (in percents) for beating 100 points stronger opponent are shown as well. We use linear extrapolation between the points given in the table and con=10, and a=70 for GoR > 2700.
GoR con a SE(100) GoR con a SE(100)
100 116 200 37.8 1500 47 130 31.7
200 110 195 37.5 1600 43 125 31.0
300 105 190 37.1 1700 39 120 30.3
400 100 185 36.8 1800 35 115 29.5
500 95 180 36.5 1900 31 110 28.7
600 90 175 36.1 2000 27 105 27.8
700 85 170 35.7 2100 24 100 26.9
800 80 165 35.3 2200 21 95 25.9
900 75 160 34.9 2300 18 90 24.8
1000 70 155 34.4 2400 15 85 23.6
1100 65 150 33.9 2500 13 80 22.3
1200 60 145 33.4 2600 11 75 20.9
1300 55 140 32.9 2700 10 70 19.3
1400 51 135 32.3


All the following examples are computed with ε set at zero:


Example 3: Both opponents have the same rating RA=RB=2400. This gives D=0 and SE=0.5 for both players. If player A wins, his new rating will be

  Rnew(A) = 2400 + 15 (1-0.5) = 2407.5

At the same time, the rating of player B drops by 7.5, i.e. Rnew(B)=2392.5

Example 4:   RA=320, RB=400 and player A wins:

  a=189,    SE(80)=0.396

  Rnew(A) = 320 + 104 (1-0.396) = 383

  Rnew(B) = 400 + 100 (0-0.604) = 340


The system also allows to include handicap games assuming that the rating difference D is reduced by 100(H-0.5), where H is the number of given handicaps. Note, that it can happen that the winning expectancy of a weaker player is larger than SE of the stronger player (i.e. the weaker player is expected to win the game) if the number of given handicaps (reduced by 0.5) is larger than the absolute value of (RA-RB)/100.

Example 5:   RA=1850, RB=2400, player A takes 5 handicaps and wins:

  D=100,    a=90,    SE(100)=0.248

  Rnew(A) = 1850 + 33 (1-0.248) = 1875

  Rnew(B) = 2400 + 15 (0-0.752) = 2389




Remarks

The post-tournament ratings are calculated assuming that every player enters the games with all opponents at the same initial (pre-tournament) rating. It means that the ratings are not reevaluated after each game (round) and the "new" ratings are computed from the "old" ones adding all contributions from the games the player completed at a given tournament. In other words, we assume that the ratings of players do not change in the process of one tournament.

If a rank professed by the player had improved significantly (at least by 2 grades for amateur players or by 1 professional grade) with respect to the highest previously professed rank, the rating of the player is reset. This measure helps to deal with fast improving players and with players who participate at included tournaments only occasionally. To avoid undesirable oscillations in the bottom part of the rating list the drop of player's rating at one tournament is restricted to 100 points.

The work on the program that calculates the ratings is still in process. In the future, the program should also be used for some statistical purposes and for the maintenance of the database of go players. We welcome any comments and suggestions.


Acknowledgement:

The rating system has been tested, with permission, on the database of professional games provided with the GoGoD Encyclopaedia CD produced by J. Fairbairn and T.M. Hall. We thank R. Kok and Ch. Gerlach for providing us with their databases of tournament results and A. Engels for maintaining a web page which helped us immensely to collect the tournament data. We would also like to thank J.-L.Gailly for advising us on the correct treatment of handicap games. Finally, we acknowledge a help of many people who have contributed with their comments and suggestions, and especially of those who have kept us informed by sending new tournament results.



Notes on submission of tournament results

The results must be submitted through the online parser which is present in the backend section of this website.
In order to be allowed to submit data, you will be requested to register a user account.
If you encounter any problems, report them to Aldo Podavini, who is responsible for the ratings maintainance and for E.G.D.

When the results are sent we need to know:

  • the name of the event
  • the place (city) where it was hold
  • the exact date of the event
  • tournament class (or the time limit including byoyomi)
  • handicap strategies (if any handicap games occured)


Tournament classes

EGF recognizes three tournament categories:
  • class A:
    well organized tournament, no handicaps in the top group, recognized by EGF member
    time limit requirements: adjusted time minimum 75 minutes, basic time minimum 60 minutes; (Fischer time: basic time 45 mins, adj. time for 120 moves: 75 mins - see remarks)
    weight for inclusion to EGF ratings: 1.00
  • class B:
    well organized tournament recognized by EGF member
    time limit requirements: adjusted time minimum 50 minutes, basic time minimum 40 minutes; (Fischer time: basic time 30 mins, adj. time for 120 moves: 50 mins - see remarks)
    weight for inclusion to EGF ratings: 0.75
  • class C:
    casual or club tournament recognized by EGF member
    time limit requirements: adjusted time minimum 30 minutes, basic time minimum 25 minutes; (Fischer time: basic time 20 mins, adj. time for 120 moves: 30 mins - see remarks)
    weight for inclusion to EGF ratings: 0.50

Remarks:
Adjusted time (TA) is calculated as
          TA = basic time + time equivalent to 45 (60) moves in standard (Canadian) byoyomi.
Sudden death - implying adjusted time = basic time - is acceptable, provided all other criteria are met.
As of October 2010 the Rating Commission has approved the inclusion of tournaments played with the
Fischer timing system. These are the rules for classify such tournaments:
TA = basic time (BT) + bonus calculated for 120 moves

  • Class A: minimum BT 45 minutes, minimum TA 75 minutes (e.g.: 45 minutes + 15'' per move)
  • Class B: minimum BT 30 minutes, minimum TA 50 minutes (e.g.: 30 minutes + 10'' per move)
  • Class C: minimum BT 20 minutes, minimum TA 30 minutes (e.g.: 20 minutes + 5'' per move)

The EGF Ratings Committee reserves the right to adjust the class of a tournament if considered necessary. The class of the event should be known before it is held. The organizer may demote the class in tournament announcement if the lower class suits better to his intentions (e.g. when new tournament system or rules are tested). The events that do not meet the specifications mentioned above are not recognized as classified EGF tournaments.


Tournament table format

The rating program processes the tournament tables written in the form of ASCII text files. The data record for each player is to be given in one line. Empty lines and everything following the semicolon sign are ignored. The results are presented in a string of entries separated by blanks. The number of rounds (included results) must be the same for each player and each result entry is given in the form:

        <opponent's place><symbol>[/<colour>[<h>]] 
where 
        <symbol> is + (a win), - (a loss) or = (jigo)
        <colour> means the colour of stones ('b/w' = black/white)
          <h>    specifies the number of given handicaps
   
Examples: 35=, 23+/w (equivalent to 23+/w0), 11-/b5 
The handicap specification can be omitted if the handicaps are computed from the difference of opponents' grades (minus a given reduction). If the player did not participate in a given round, the result is still to be specified in one of the following ways:
        0+  a free win
        0-  a free round
        0=  a free round (0.5 added to the score and MM)


Examples of some tournament tables:

t970920b.h2 - handicap games, handicap = difference of grades - 2 (defined by the file extension; h9 extension used for even games)
e961122.h9 - even games, example of a team tournament
t990220f.h9 - even and handicap games specified


In the
Admin backend you will find extensive documentation, with further specifications for formatting the results table.

References to other rating systems:

 
 
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