ELO History

As I navigate various forums, I’m always amazed at how many players are ignorant of the ELO rating system.  I don’t mean the math involved…I don’t understand that very good either. I’m talking about what the ELO system actually measures and its limitations. That’s what I want to pontificate on here so I’ve given links to some informative posts on the subject given in no particular order.

Here’s an excellent quote from the Exeter Chess Club: One of the more frequently asked questions I receive concerning chess is "What is a chess rating, and how do you get one?" This file will attempt to answer that question in a clear and concise manner: A chess rating is a guideline for measuring a player's performance in tournaments, and ranking him/her against other players. While most people will tell you it is a measure of a player's knowledge of chess or chess ability, this is not exactly true, as there are people who perform better or worse under tournament conditions, just as there are people who perform poorly on tests even though they know the material. Many other psychological factors come into play in tournaments, such as competitive spirit, that are reflected in tournament results, and therefore also in a person's rating. So chess ratings measure performance, not ability

An interesting interview with Prof. Elo
Explains the ELO System in simple terms
Chessdotcom article discusses the ELO and Glicko Systems

Jess Sonas’ site, Chessmetrics, is THE site for lots of fascinating discussion of the problems in comparing the ratings of players, past and present. This is the historical site. For more modern discussions, visit his new Chessmetrics site

Chessbase analysis of players past and present. This is a fascinating article where they analyzed games and based their evaluation on the average difference between moves played and best evaluated moves by computer analysis and according to this analysis, the winner was Capablanca. One word of caution using this method though and it’s basically what I poated in the Blog below: This result should be interpreted in the light of the comparatively low complexity of positions in Capablanca's games which is quite in line with the known assessments in the chess literature of his style. Kasparov in his set of books My Great Predecessors speculates that Capablanca occasionally did not even bother to calculate deep tactical variations, preferring instead to play moves that were clear and positionally so strongly justified that calculation of variations was simply not necessary. They also used a blunder-rate measurement are similar. Tigran Petrosian ranked first and Steinitz, who lived in an era of tactical romantic chess, took last place.

An example of manipulating the system by Claude F. Bloodgood III

There was a time when the Fischer Boom caused a great influx of new players who caused ratings deflation so the USCF started adding free points; in some cases you got rating points just for showing up and playing! See point 3

Has some interesting historical information. About ¾ of the way down the page there’s a discussion of the ELO system and some abuses of it over the years, including fiddle and bonus points.