The Harrwitz Attack, Two Knights Defense, Blockade Line is a variation of the Queen's Gambit Declined, catalogued as ECO D37. The line runs 1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. Nf3 Be7 5. Bf4 O-O 6. e3 Nbd7 7. c5, reaching the position shown below after 13 half-moves.
Both sides have pawns in the centre (White on d4, Black on d5). Development is level at three minor pieces each. It is Black to move after seven moves. Black has castled while White’s king is still uncommitted.
On the Queen's Gambit Declined generally: A solid and respected response to the Queen's Gambit. Black maintains a strong central presence.
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The Harrwitz Attack, Two Knights Defense, Blockade Line goes 1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. Nf3 Be7 5. Bf4 O-O 6. e3 Nbd7 7. c5. It is a variation of the Queen's Gambit Declined and is catalogued as ECO D37.
The Harrwitz Attack, Two Knights Defense, Blockade Line is ECO D37. ECO codes group openings by their move order, so nearby codes cover closely related lines of the Queen's Gambit Declined.
Stockfish evaluates the position after 1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. Nf3 Be7 5. Bf4 O-O 6. e3 Nbd7 7. c5 at +0.18 at depth 18, which is balanced. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
Both sides have pawns in the centre (White on d4, Black on d5). Development is level at three minor pieces each. It is Black to move. Black has castled while White’s king is still uncommitted.