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Explanation
The St. Petersburg Variation appears when Black answers White's e3 advance by moving the b-pawn to b6. This prepares a queenside fianchetto: the bishop on c8 will develop to b7 and look along a long diagonal toward the center and White's kingside.
b6 creates a flexible plan but does not challenge the center by itself. White can develop the king's bishop to d3, the knight to f3, and secure the king. Black must connect the future bishop on b7 with a c- or d-pawn advance to exert real pressure on White's central pawns.
This variation belongs to the e3 framework of the , but it is defined by a specific Black choice. It should not be confused with the Romanishin: there White plays g3 to develop the king's bishop; here Black plays b6 to develop the queen's bishop.
Common confusions
St. Petersburg and Romanishin
In St. Petersburg, Black prepares the bishop for b7 with b6; in the Romanishin, White prepares the bishop for g2 with g3.
View termSources
- 1.Nimzo-Indian Defense: St. Petersburg Variation, Chess.com
- 2.Nimzo-Indian Defense, Chess.com
- 3.Lichess chess-openings dataset: ECO volume E, Lichess