Queen's Gambit Declined: Three Knights Variation

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3

Queen's Gambit Declined: Three Knights Variation is catalogued under ECO code D37. It is reached after 4 moves (7 half-moves): 1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3. After the last move it is Black to play. White opens 1. d4. It is a named variation of the Queen's Gambit Declined, which has 198 catalogued lines in total. 5 deeper lines continue from here, listed below.

Position shown after the last move; Black to play.