As Historic Elo Elo refers to a number that has been calculated for those chess masters who were active before the actual introduction of the Elo ratings. It will help you to compare the playing strength of early and active chess masters.
The FIDE introduced the Elo numbers only in the year 1970. Since then, all declared for rating tournament are recorded and evaluated. The compilation of all previously determined tournament results is, however, quite possible, and the application of the present-day calculation method to a time long past, nothing stands in the way.
Already Arpad Elo even turned to such calculations, however, it lacked a comprehensive and reliable data base.
The American mathematician Jeff Sonas recorded since 2001, all available historical competition and tournament results and published his calculations on the Internet.
The data obtained in this way give some information on the playing strength of chess masters of the past - or of actual, that is mathematically calculated rank - compared with their contemporaries.
Sonas calculated on the basis of his recalculations the theoretical figures of the later ratified by FIDE tournaments ( the calculations are constantly updated ) and came to different conclusions. In particular, here came the ( often criticized ) inflation vulnerability of the Elo rating to the fore, as Sonas ' numbers are far higher than those published by the FIDE. Due to the heterogeneous structure of Sonas ' game database go to his calculations, but also games, which - were not played under tournament conditions, such as rapid games, simultaneous games and lots of theme tournaments - then and now.
The highest historical Elo rating was calculated for Bobby Fischer; In October 1971 she was 2895th