Caissa Codex
E43

Nimzo-Indian Defense: St. Petersburg Variation 9. a3 Be7

Chess diagram: Nimzo-Indian Defense: St. Petersburg Variation after 9…Be7

Type a move and press Enter: e4, Nf3, O-O, or from and to squares like g1f3 (e7e8q to promote). The board is also played with the mouse.

Play any move on the board to explore from there, or step through the line with ‹ › and the arrow keys.

Statistics from Lichess

180 games: White 57.2% / Draw 5.0% / Black 37.8%

The moves played next. Pick one to see it on the board.
Next moveGamesWhite / Draw / BlackW / D / B
176176
44

Rated Lichess games between players rated 1600 to 2500, from the Lichess opening explorer, updated Oct 30, 2026

Engine evaluation

+0.15 The position is about equal

Best play: 10. exd4 Bxf3 11. Qxf3 Nc6 12. Be3 e5 13. dxe5 Nxe5 14. Qf5 Nxd3

Stockfish 19, depth 30, after the line's last move. Scores are in pawns, from White's side.

Overview

Nimzo-Indian Defense: St. Petersburg Variation (ECO E43, Indian Defenses) is a variation of the Nimzo-Indian Defense: St. Petersburg Variation, reached after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. e3 b6 5. Bd3 Bb7 6. Nf3 O-O 7. O-O c5 8. Na4 cxd4 9. a3 Be7 (9 moves).

In 180 rated Lichess games between players rated 1600 to 2500, White won 57.2%, Black 37.8% and 5.0% were drawn. White's most played move here is 10. exd4, in 98% of those games.

Written from the Lichess opening list and explorer. Know this line well? Write about it.

Write a description or report a mistake
What would you like to send?

Markdown supported (headings ###, bold, lists, links). Submissions are reviewed before publishing.

Cite this page

Caissa Codex. “Nimzo-Indian Defense: St. Petersburg Variation (E43)”. Lichess data as of 30 Oct 2026. https://chesscodex.org/openings/nimzo-indian-defense-st-petersburg-variation-12

https://chesscodex.org/openings/nimzo-indian-defense-st-petersburg-variation-12