New Rating System for AICCF Server

AICCF Ratings have been revised to the modern Glicko-2 ratings system. Monthly rating lists are re-compiled starting from the inception of AICCF server. The first Glicko rating list is that of September 2009. Results from the postal-era are not considered (except for start ratings).

Where can I see the new ratings?

  1. (From the menu list on the server home page)
    You can display the rating graph of any member. The graph starts from September 2009 (or later according to the date of joining of the player)
  2. (From the menu list on the server home page)
    Rating lists are available for each month, starting September 2009. When displayed in the order of highest ratings, the players who have a Rating Deviation of 350 or larger are shown lower down in the list, even if the rating is higher. Rating Deviation calculation is a part of the Glicko system. Large values indicate that the player is inactive. Players from the postal era who are not participating in server tournaments, new players, and players who gradually become more inactive will therefore not be seen near the top of the list.
  3. After login, on your games-list page, there is a "View Results" button. Here you can see results of the previous month. The Glicko rating of the previous month and the current month are also shown. You can change the options to view the results of any earlier month and it is also possible to see the results and rating progress of any other member.
  4. Make Move page
    Your Glicko rating and that of your opponent will be seen next to the photo.

Motivation

When the AICCF Server was started in 2009 we continued with the rating system then in force for the AICCF postal games. This system is very old and does not give reliable results. Moreover the rating values are lower (about half) of the standard Elo system used by FIDE and ICCF.

Recent Advances in Chess Rating Systems

Elo ratings, a creation of Prof. Arpad Elo, became the de facto standard for chess ratings world wide from 1960 onwards. However of late, in view of the simplifications made in the Elo formuls and the increased level of competition, have led to new and better rating systems to be devised. The latest system is Glicko-2 which evolved from the original Glicko (1995), then Glicko-Boost (around 1999) and eventually Glicko-2 (2000). The Glicko system is an invention of Prof. Mark Gilman see www.glicko.net/glicko.html. It is used in modern chess servers like like Lichess, Free Internet Chess Server, Chess.com.

FIDE is yet to adopt Glicko ratings, possibly because of the large number of continuoiusly running games. Scheming Mind uses Glicko-1. ICCF still uses the Elo system, but has announced that it will use an interim modified Elo system in 2017 and will finally change to change to Glicko by 2018.

Choice of Chess Rating System for AICCF

It is logical to use the latest system and accordingly we selected Glicko-2 although ICCF has yet to adopt it. From now on, we will consistently use the Glicko system. Rating Lists will be computed on the 1st of every month. The next Rating List will become available after 1st January 2017.

Why is my AICCF Glicko rating lower than my ICCF Rating?

ICCF Ratings are based on ICCF results while AICCF Ratings are based on AICCF results. The only exception is AICCF Championships which are rated in both systems.

Glicko ratings are on the same scale as Elo, but the Glicko system takes care of artificial rating inflation. This is why Glicko ratings are often lower than Elo.

Start Rating

When a player joins, his initial Glicko rating is fixed at 1500. FIDE GMs and IMs start with their FIDE rating and AICCF postal-era players start with a scaled value of their old AICCF raing. Subsequently ratings are computed every month and reliable ratings are obtained after the player has played many games.

What is Rating Deviation and Volatility that I see in the Rating Lists?

Rating deviation (RD) is an indication of how uncertain a player's rating is. At start, a player is assigned an RD of 350. If his rating is 1500, then it means his estimated rating is in the range of 1500 plus or minus 700 (twice the RD), that is 800-2900.

A high RD indicates that a player may not be competing frequently or that a player has only competed in a small number of tournament games. A low RD indicates that a player competes frequently. If a player is inactive, his rating remains the same, but his Rating Deviation increases.

Volatility indicates the degree of expected fluctuation in a player's rating. Volatility is high when a player has erratic performances, and is low when the player performs at a consistent level.