The exclusive annotated database. Contains more than 5 million games from 1560 to 2009 in the highest ChessBase quality standard. 65,000 games contain commentary from top players, with ChessBase opening classification with more than 100,000 key positions, direct access to players, tournaments, middlegame themes, endgames. The largest topclass annotated database in the world.
The most recent games of the database are from the middle of November 2009. Mega 2010 also features a new edition of the playerbase. As usual, this is where most of the work was done. As the player index now contains already more than 240,000 entries, it made sense to use an adapted playerbase which includes about 258,000 names. Doing this, the photo database was extended as well to contain 31,000 pictures now.
Some noteworthy points about the Mega Database:
Carefully corrected gamescores
A large percentage of the games originally appeared in annotated form in ChessBase Magazine. In the process of annotating the games many errors in the game notation were discovered. They were also screened by other experts and went through numerous other quality controls before they were included in the Mega Database.
Unified spelling of players' and tournament names
Without standardized spelling of players' names a number of database functions would become less reliable or useless (player dossier, preparation for specific opponents). ChessBase invests a lot of effort into correctly identifying all the players in a tournament and making sure all spellings are standardized.
Careful editing of Elo ratings
All statistical analyses in a database rely on complete and accurate rating information. This is especially true of openings statistics, the success rates and evaluation of variations, repertoire suggestions, sorting of games and many other functions that use information on the relative strengths of different players. So ChessBase takes great pains to insure that Elo ratings are included correctly for every player in every game.