Caissa Codex
D37

Queen's Gambit Declined: Harrwitz Attack, Two Knights Defense, Blockade Line

Chess diagram: Queen's Gambit Declined: Harrwitz Attack, Two Knights Defense, Blockade Line after 7. c5

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.

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Statistics from Lichess

33,850 games: White 54.0% / Draw 7.2% / Black 38.8%

The moves played next. Pick one to see it on the board.
Next moveGamesWhite / Draw / BlackW / D / B
20,19420K
5,2555,255
3,8473,847
2,2982,298
866866
556556
503503
207207

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

Engine evaluation

+0.31 White is slightly better

Best play: 7... c6 8. h3 b6 9. b4 a5 10. a3 h6 11. Qb1 Bb7 12. Bd3

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

Overview

Queen's Gambit Declined: Harrwitz Attack, Two Knights Defense, Blockade Line (ECO D37, Closed & Semi-Closed Games) is a declined gambit that starts 1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. Nf3 Be7 5. Bf4 O-O 6. e3 Nbd7 7. c5.

In 33,850 rated Lichess games between players rated 1600 to 2500, White won 54.0%, Black 38.8% and 7.2% were drawn. Black's most played move here is 7…c6, in 60% of those games.

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How to play against the Queen's Gambit Declined: Harrwitz Attack, Two Knights Defense, Blockade Line

7…Nh5 scores best for Black: 48.0%, with Black winning 42.7% and White 46.7% of 5,255 games. The most played, 7…c6, scores 41.8% in 20K games, and 7…b6 scores lowest: 38.8%. Stockfish's first choice is 7…c6.

Main answers: those played in at least 5% of these games. Score: Black's wins plus half the draws, in rated Lichess games between players rated 1600 to 2500. How to play against other popular openings

Transpositions

This position is also reached from these lines, by another move order:

Cite this page

Caissa Codex. “Queen's Gambit Declined: Harrwitz Attack, Two Knights Defense, Blockade Line (D37)”. Lichess data as of 30 Oct 2026. https://chesscodex.org/openings/queens-gambit-declined-harrwitz-attack-two-knights-defense-blockade-line

https://chesscodex.org/openings/queens-gambit-declined-harrwitz-attack-two-knights-defense-blockade-line