Brief explanation: • Edo ratings: A 'simultaneous' rating system for the retroactive rating of chess players over a historical period. Edo ratings are calculated in a two-step process. Raw ratings are obtained by an iterative procedure from a gigantic 'crosstable' in which each player in each year of their recorded career is treated as a separate 'player' and, for consistency, hypothetical drawn self-games are introduced between a player in one year and the same player in the next. The second step is to adjust for the underlying probability distribution of ratings of chess players in general.
• Rating deviations (uncertainties) are listed after the ratings in parentheses. The rating estimate is likely to be accurate to within this many rating points (or twice as many for 95% certainty).
• Number of games on which the ratings are based in a given year are listed in the Games column.
• Rank indicates the world ranking in a given year, at least among players for whom we have results over a period of years including the given year.