Jeff Sonas is a
statistical chess analyst who invented the
Chessmetrics
Chessmetrics is a system for rating chess players devised by Jeff Sonas. It is intended as an improvement over the Elo rating system.
Implementation
Chessmetrics is a weighted average of past performance. The score considers a player's win percen ...
system for rating chess players, which is intended as an improvement on the
Elo rating system
The Elo rating system is a method for calculating the relative skill levels of players in zero-sum games such as chess. It is named after its creator Arpad Elo, a Hungarian-American physics professor.
The Elo system was invented as an improved c ...
. He is the founder and proprietor of the
Chessmetrics.com website, which gives Sonas' calculations of the ratings of current players and historical ratings going back as far as January 1843. Sonas has written dozens of articles since 1999 for
ChessBase.com and other
chess
Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to dist ...
website
A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and Wi ...
s. He was a participant in the FIDE ratings committee meeting in
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates ...
, Greece in June 2010.
In 2002 he wrote for chessbase.com that a 24 k-factor would be ideal for predicting game results, instead of the standard 10 for high level players. In 2009
John Nunn
John Denis Martin Nunn (born 25 April 1955) is an English chess grandmaster, a three-time world champion in chess problem solving, a chess writer and publisher, and a mathematician. He is one of England's strongest chess players and was forme ...
wrote he needed more proof for the change. Sonas replied saying Nunn didn't thoroughly read his first article, but also says there is room for improvement, as he didn't analyze what it should be for low level players.
In 2011 after analyzing 1.5 million FIDE rated games, he demonstrated according to the Elo formula, two players having a rating difference of X, actually have a true difference more like X(5/6). This means players are consistently losing points for winning, and winning points for losing, since the Elo formula is incorrectly predicting results. He also says the 400 point rule should be raised to 700-900, or be gotten rid of entirely. The rule says that players with an Elo score more than 400 points apart will be treated as though they are only 400 points apart.
[https://en.chessbase.com/post/the-elo-rating-system-correcting-the-expectancy-tables]
Sonas graduated with honors with a B.S. in Mathematical and Computational Sciences from
Stanford University in 1991.
References
Year of birth missing (living people)
Living people
Chess people
Stanford University alumni
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