For more information about the Rating System we operate see the Rating System FAQ, which uses the European Go Federation (EGF) rating system.
Many British tournaments are run on the McMahon system, which tries to pair players of equal strength. This relies on players entering the tournament at a realistic grade so that fair games between players can be achieved. Many European tournaments are also run on the McMahon system, so again we would like to ensure that our players perform satisfactorily in European events. Consequently the aim of our ratings policy is:
It is recognised that not all players are able to play in every tournament and some players' published ratings may lag excessively behind their actual playing strength. To address this issue, our policy regarding which games count towards rating points is as follows:
The policy is:
We encourage on-line players to enter over-the-board tournaments. In order to establish a relation between on-line server grades and our strengths we will be setting up a system to collect information from players who play in tournaments as well as on-line. Until a meaningful correlation between server and our grades is established, the following guide will apply for an on-line player entering one of our tournaments for the very first time or after a long absence:
Since November 2003, British Go Association dan certificates have been awarded based on our ratings, which in turn are based on the European rating system. You will be awarded a dan certificate under the following conditions.
COMMENTS
The first time you play in a rated tournament, your strength is initialised to your tournament entry grade - which may not be very accurate. Only after you have played in several tournaments does it settle down to a reasonable measure of your playing ability. The conditions above ensure that certificates are not awarded during this initial settling down period.
An instability can also occur after a rating reset, when you already have a rating, but enter at a grade two stones higher than your previous highest grade. In this case your rating may drop below the reset value, but as long as it eventually rises again to reach the next dan level threshold, you gain a certificate when all the above conditions are met.
In the first instance tournament directors are encouraged to be proactive in ensuring that their players are entering at realistic grades. The results of all our tournament are scrutinised and submitted to the EGF by our ratings official. If anomalous entry grades are present in the results, submission of games to the EGF rating system may be delayed and the following procedure adopted:
It is very much hoped that players' entry grades are essentially self managed, and much information is provided to help players determine their entry grades. However, if any player wishes to complain about the published rating of either themselves or another player on our rating list then the following procedure must be adopted:
Strengths are calculated from ratings in the European Go Database:
strength = (rating - 2100)/100 (rounded to one decimal place)
COMMENT
Until early 2017 we used a linear regression of player's grades vs rating to calculate the player strength as presented in our rating page. Although this process gave plausible results in the early years of the rating system, the method was degraded by the drop in the average rating of all European players. By early 2017, a nominal shodan (rating 2100) had a strength of 1.7d rather than 1.0d. The procedure was abandoned early in 2017.