Chess opening · ECO D31
Queen's Gambit Declined: Queen's Knight Variation
With 3.Nc3, White brings a second piece to bear on d5 and gets ready to push e4 if Black ever lets go of that square. The knight also hands Black a target, since a bishop on b4 can now pin it to the king. This is a crossroads more than a finished setup: Black's third move steers the game into several systems with very different pawn structures.
- Rank by weighted share
- #62 of 159
Key moves
1. d4 d5 2. c4 e6 3. Nc3
- 3. Nc3The knight hits d5 alongside the c4 pawn and covers e4, so White can think about e4 once d5 gives way. Sitting on c3, it also blocks the c-pawn and stands on the diagonal from b4 to e1, where a black bishop could pin it.
Counting attackers and defenders on d5
Right now d5 is hit twice, by the c4 pawn and the c3 knight, and held twice, by the e6 pawn and the queen on d8 looking up the open d-file. The count is even, and White's usual Nf3 and Bg5 are aimed at the knight Black brings to f6 to hold d5.
That is the main job of 3...Nf6: it adds a third defender, gets Black closer to castling, and keeps an eye on e4 so the white e-pawn cannot advance for free.
Black's third-move menu
3...c6 backs d5 with a second pawn, a setup that turns into the Semi-Slav once ...Nf6 follows. 3...c5 is the Tarrasch, where Black opens the center and accepts the chance of an isolated d-pawn for free piece play.
3...Be7 develops the bishop first and keeps the knight's options open. 3...Bb4 puts the pin on at once, and 3...dxc4 takes the pawn a move later than the Queen's Gambit Accepted would, with e6 already played.
Top replies by rating
Nf6 leads every band. Bb4 sits in the top three from 1200 to 1799, then gives way to c5, the Tarrasch move, among players rated 1800 and up.
Questions
Why does ...Bb4 come up here and not after 3.Nf3?
Because the pin needs a target. With the knight on c3, a bishop on b4 ties it to the king on e1 and makes the e4 push harder to arrange. After 3.Nf3 there is nothing on c3 to pin, and ...Bb4+ is just a check that White can block.
Related openings
Try it on the board. The first coached game and three analyses are free.