FIDE April 2013 ratings – and reform plans

FIDE April 2013 – Top 100 Players

Top climbers and descenders

Here's a list of all players from the top 100 who gained or lost five or more points.

FIDE Top Women

FIDE Top Juniors

• Top 100 rankings juniors

FIDE Top Girls

• Top 100 rankings girls

New rating plans – adjusting the K-factor

The Elo rating system is a method for calculating the relative skill levels of players in two-player games such as chess. It is named after its creator Árpád Imre Élö, a Hungarian-born American physics professor. It was adopted by the USCF in 1960 and by FIDE in 1970. Initially one or two rating lists were published per year, and from 2000 on four lists per year. By the second half of 2009 there were six rating lists per year.

In July 2012 FIDE started publishing monthly ratings, which was a great and commendable service to chess players but came with a downside: the lists seldom changed in a way that would attract the general chess public to study them. How high had Magnus Carlsen climbed, any changes in the top ten – that was what fans would glance at the list to find out. If you look at the rating changes of the top 100 players you will find just thirteen that have shown noteworthy change, noteworthy being defined as a loss or gain of at least five points. From a publicity point of view this was not exactly a satisfying state of affairs, and so FIDE decided at the beginning of this year to look into the question of adjusting the K-Factor.

When calculating ratings changes, a player’s performance in an event is only one part of the equation. The other part is the K-Factor, which is basically used to avoid uncontrolled swings due to a particularly good or bad performance. The K-Factor moderates the gains or losses: a lower value will allow ratings to fluctuate less, a higher value will lead to larger swings. FIDE uses the following ranges:

• K = 30 (was 25) for a player new to the rating list until he or she has completed events with a total of at least 30 games. This allows talented newcomers to up the list faster than others.

• K = 15 as long as a player's rating remains under 2400.

• K = 10 once a player's published rating has reached 2400, and he or has also completed events with a total of at least 30 games. Thereafter it remains permanently at 10.

To bring more variance in the ratings and generate more public interest FIDE decided to "go all the way" and adopt a K-Factor of 60 for all players. The announcement was meant to coincide with the publication of the April 2013 Ratings, and calculations had aready been done. But just before publication a minor bug was discovered in the algorithm – one that caused the "regular" ratings with K=10 to be slightly skewed – and so the traditional calculation was used for the lists we have shown above.

However, starting from May 2013 FIDE will be using the K-60 system, while providing, we are told, the traditional K-10 ratings in parallel until the end of the year. Starting from 2014, however, only the K-60 ratings will be published. "Just take a look, they are much more exciting than the traditional list," said a FIDE spokesperson, who supplied us with the April 2013 list (which was subsequently abandoned). It gives us a very good idea of what is coming and what is in store for us.

The great K-Factor debate

• 22.10.2002 – The Sonas Rating Formula – Better than Elo?
  The Elo formula has served the chess world quite well for a long time. However, statistician Jeff Sonas believes that the time has come to make some significant changes to that formula. He presents his proposal in this milestone article. Suggestion #1: Use a more dynamic K-Factor...

• 27.4.2009 – FIDE: Rating Regulations – The K-Factor
  FIDE has reacted to concerns of players and decided not to simply change the K-Factor in its rating calculation, but to in fact publish two parallel lists for a year and then review the results. Press releases.

• 28.4.2009 – Macieja: The increase of the K-factor is essential
  A passionate appeal by GM Bartlomiej Macieja not to delay the decision but increase the K-factor immediately. In fact he advocated recalculating the lists of the last two or even five years.

• 29.4.2009 – FIDE: We support the increase of the K-factor
  Yesterday we published a letter by GM Bartlomiej Macieja asking the World Chess Federation not to delay the decision to increase the K-factor in their ratings calculation. Today we received a reply to Maceija's passionate appeal from FIDE, outlining the reasons for the actions. In addition interesting letters from our readers, including one from statistician Jeff Sonas. Opinions and explanations.

• 30.4.2009 – Nunn on the K-factor: show me the proof!
  With the debate raging over FIDE's decision to change or not to change the K-factor used in calculating players' ratings, we are glad to receive an important message from our voice-of-reason grandmaster. Dr John Nunn says "there seems no real evidence that K=20 will result in a more accurate rating system, while there are a number of risks and disadvantages." His explanation and reader feedback.

• 7.5.2009 – Thompson: Leave the K-factor alone!
  Ken Thompson, the father of Unix and C, and a pioneer of computer chess, believes that the current rating system isn't broken and that the status quo is better than change. If anything the ratings should be published more often – every day if possible. Food for thought.

• 11.5.2009 – Rating and K-factor: wrapping up the debate
  The discussions regarding the K-factor – the rate at which ratings go up or down when they are calculated – reaches its climax with a wrap-up article by Dr John Nunn, grandmaster and mathematician, who evaluates the arguments that have been presented by the different parties. After this it is up to FIDE, which has already initiated positive steps settle the matter. Final installment.

• Wikipedia: Most accurate K-Factor

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