Chessmetrics

Chessmetrics

Chessmetrics is a system for rating chess players devised by Jeff Sonas. It is intended as an improvement over the Elo rating system.

Contents

Implementation

Chessmetrics is a weighted average of past performance.[1] The score considers a player's win percentage against other players weighted by the ratings of the other players and the time elapsed since the match. A 10% increase in performance is equivalent to an increase of 85 rating points.

The weighting of previous matches digresses linearly from 100% for just-finished matches to zero for matches conducted more than two years ago.

Formulas

Performance rating adjustment after tournament:

Performance Rating = Average Opponents' Rating + [(PctScore - 0.50) * 850]

Weighting of past tournaments (age in months):

100% * (24 - age)

Perceived advantages

In 2006 economists Charles C. Moul and John V. C. Nye used Chessmetrics to determine the "expected" results of games, and wrote, "Ratings in chess that make use of rigorous statistics to produce good estimates of relative player strength are now relatively common, but comparing ratings across different time periods is often complicated by idiosyncratic changes (cf. Elo, 1968 for the pioneering discussion). Sonas uses the same rating formula throughout our sample and updates this rating monthly instead of annually, as is more common. Moreover, retrospective grading allows him to establish rankings that are unbiased estimates of the “true” relative strengths of players."[2]

Jeff Sonas, Chessmetrics' author, repeatedly emphasises the importance of a rating system's ability to "predict" results (during testing the results to be "predicted" are those of past games whose outcomes are known to the tester).[3]

Sonas also claims that Chessmetrics has other advantages over Elo ratings:[3]

  • Elo ratings have a built-in bias against top players, in other words a top player's rating will suffer if he / she achieves against a lower-rated player the percentage result that the players' Elo ratings predict.
  • Chessmetrics is more responsive to change than Elo ratings, for example Chessmetrics will track more promptly and accurately improvements in the playing strength of a rising star. Sonas regards this as an important part of Chessmetrics's superior ability to predict results.
  • Chessmetrics takes account of the empirically-measured difference in results when playing as White or Black, which the Elo system ignores.

Perceived disadvantages

Chessmetrics occasionally gives strange looking results, particularly for players with long periods of inactivity. For instance, World Chess Champion Emanuel Lasker was inactive for much of 1912–1914, and as a consequence dropped from #1 to #12 in the world in the Chessmetrics rankings,[4] just before his famous victory ahead of all the world's other leading players at the 1914 Saint Petersburg chess tournament.

Chessmetrics can only be used to compare the level of a player against their peers; it is not appropriate to use Chessmetrics to compare players of different era. For example, GM John Nunn has highlighted the absurdity of attempts to compare the objective playing strengths of players from different eras: He used the example of Hugo Suechting, world ranked 27 and rated 2559 by Chessmetrics in 1911, after the Elite tournament in Karlsbad. An analysis of Suechting's games from that period suggests that his level of play was at best 2100 by today's standard.[5]

Chessmetrics, like any other ratings system, can only be used as a guide.Template:Ref missing

Popularity

The original article on Chessmetrics was published in Chessbase in October 2002.[3] Since then, Chessmetrics has become reasonably well known, due to numerous articles in Chessbase and The Week in Chess.[6]

Respected chess author John L. Watson has referred to Chessmetrics numbers,[7] and Chessmetrics has been cited in at least two academic papers.[2][8]

See also

  • Chess rating systems

Notes

  1. ^ Chessmetrics formulas page
  2. ^ a b Charles C. Moul and John V. C. Nye (May 2006). "Did the Soviets Collude? A Statistical Analysis of Championship Chess 1940–64". The Social Science Research Network. http://papers.ssrn.com/sol3/papers.cfm?abstract_id=905612. Retrieved 2008-07-08.  Full article freely available via links on the cited web page.
  3. ^ a b c Jeff Sonas (22 October 2002). "The Sonas Rating Formula – Better than Elo?". http://www.chessbase.com/newsdetail.asp?newsid=562. Retrieved 2008-07-08. 
  4. ^ Chessmetrics Player Profile: Emanuel Lasker, Chessmetrics web site
  5. ^ Nunn's criticism
  6. ^ For instance, Chessmetrics articles on Comparing top chess players throughout history at Chessbase: Part 1 Part 2 Part 3 Part 4
  7. ^ Book Reviews, #82, by John L. Watson, published at The Week in Chess
  8. ^ Computer Analysis of World Chess Champions, M.Guid and I.Bratko, ICGA Journal (Vol 29, No. 2, June 2006, pages 65–73).

External links


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Chessmetrics — es un sistema de clasificación de jugadores de ajedrez ideado por Jeff Sonas. Contenido 1 Implementación 1.1 Fórmulas 2 Ventajas Percibidas 3 Véase también …   Wikipedia Español

  • Emanuel Lasker — Infobox chess player playername = Emanuel Lasker birthname = Emanuel Lasker country = GER datebirth = December 24, 1868 placebirth = Berlinchen, Prussia (now Barlinek, Poland) datedeath = January 11, 1941 (aged 72) placedeath = New York City,… …   Wikipedia

  • The Staunton-Morphy controversy — concerns the failure of negotiations in 1858 for a chess match between Howard Staunton and Paul Morphy and later interpretations of the actions of the two players. The details of the events are not universally agreed, and accounts and… …   Wikipedia

  • Methods for comparing top chess players throughout history — This article examines a number of methodologies that have been suggested for the task of comparing top chess players throughout history, particularly the question of comparing the greatest players of different eras. Statistical methods offer… …   Wikipedia

  • Adolf Anderssen — Infobox chess player playername = Adolf Anderssen birthname = Karl Ernst Adolf Anderssen country = GER datebirth = birth date|1818|7|6 placebirth = Breslau, now Wrocław Poland datedeath = death date and age|1879|3|13|1818|7|6 placedeath = title …   Wikipedia

  • Paul Keres — Infobox chess player playername = Paul Keres caption= birthname = Paul Keres country = EST flag|Soviet Union|1923 datebirth = birth date|1916|1|7 placebirth = Narva, Estonia, Russian Empire datedeath = death date and age|1975|6|5|1916|1|7… …   Wikipedia

  • Wilhelm Steinitz — Infobox chess player playername = Wilhelm Steinitz caption= birthname = Wilhelm Steinitz country = flag|Austrian Empire USA datebirth = birth date|1836|5|17 placebirth = Prague, Bohemia datedeath = death date and age|1900|8|12|1836|5|7 placedeath …   Wikipedia

  • Mikhail Botvinnik — Full name Mikhail Moiseyevich Botvinnik Country Soviet Union Born August 17, 1911( …   Wikipedia

  • Joseph Henry Blackburne — Infobox chess player playername=Joseph Henry Blackburne caption=Joseph Henry Blackburne, the Black Death birthname=Joseph Henry Blackburne country=ENG datebirth=December 10, 1841 placebirth=Manchester, England datedeath=September 1, 1924 (Aged c …   Wikipedia

  • Garry Kasparov — Infobox chess player playername = Garry Kasparov caption= Garry Kasparov, 2007 birthname = Garry Kimovich Kasparov (Гарри Кимович Каспаров) country = RUS datebirth = birth date and age|1963|4|13 placebirth = Baku, Azerbaijan SSR, Soviet Union… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”