How to play the Nimzo-Indian? Does White have promising variations available to him or can Black construct a water-tight repertoire? The answers are provided by the Powerbook based on more than 356 000 games, most of which were played by engines.
Grünfeld Defence Powerbase 2021 is a database and contains 10826 top-class games from Mega 2022 and the Correspondence Database 2020, of which 1136 are annotated.
The major part of the material on which the Grünfeld Defence Powerbook 2021 is based comes from the engine room of playchess.com: 232 000 games. To this imposing mass we have added another 70 000 games from Mega and from correspondence chess.
For the Slav and Semi-Slav Powerbook 2021 the ratings average was set at 2400. 1.76 million games from the engine room of playchess.com met this threshold, to which were added over 80 000 games played by humans.
Slav and Semi-Slav Powerbase 2021 is a database and contains a total of 10 610 games from Mega 2021 or the Correspondence Database 2020, of which 1030 are annotated.
Petroff Defence Powerbase 2020 is a database which contains 4821 high class games from Mega 2020 and the Correspondence Database 2020, of which 648 annotated.
The major part of the material on which the Petroff Defence Powerbook 2020 is based comes from the engine room of playchess.com: 260 000 games. This imposing number is supplemented by another 11 000 from Mega and from correspondence chess.
The major part of the material on which the King's Gambit Powerbook 2020 is based is sourced from the engine room of playchess.com: 30 000 games. Another 3500 games from Mega and from correspondence chess have been added to this corpus.
King's Gambit Powerbase 2020 is a database and contains a total of 2531 games from Mega 2020 or the Correspondence Database 2020, of which 112 are annotated.
The Ben-Oni Powerbook 2020 consists for the greater part of engine games (44 600), to which has been added high-value material from Mega and the Correspondence Database (23 600).
The Benoni Powerbase 2020 is a database and contains a total of 5955 games from Mega 2020 or the Correspondence Database 2020, of which 796 are annotated.
The Volga Benko Gambit Powerbook 2020 is based on over 21 000 games from the engine room of playchess.com and also 12 000 games from Mega 2020 and the Correspondence Database 2020
