D42 Queen’s Gambit Declined: Semi-Tarrasch Defense, Main Line
D42 holds a single named line. It leaves D41 (Queen’s Gambit Declined: Semi-Tarrasch Defense, Pillsbury Variation) with 6...Nc6 7.Bd3. Black, to move in that position, has 43 legal moves, the third-highest count of the 44 Queen’s Gambit codes. That final move, by the bishop, opens a line for the rook on h1.
| # | White | Black |
|---|---|---|
| 1 | d4 | Nf6 |
| 2 | c4 | e6 |
| 3 | Nf3 | d5 |
| 4 | Nc3 | c5 |
| 5 | cxd5 | Nxd5 |
| 6 | e3 | Nc6 |
| 7 | Bd3 |
Moves only D42 plays
Same as D41 up to 5.cxd5, then:
- 5...Nxd5 The knight on f6 takes the pawn on d5, opening a line for the queen on d8, attacking the knight on c3.
- 6.e3 The e-pawn advances to e3, covering d4 and f4, opening a line for the queen on d1 and the bishop on f1.
- 6...Nc6 The knight leaves b8 for c6, opening a line for the rook on a8.
- 7.Bd3 The bishop leaves f1 for d3, opening a line for the rook on h1.
The road to D42
- 1.d4 … 4...c5six earlier stops: A40, A45, A50, D37, D40, E10
- 5.cxd5D41 Semi-Tarrasch Defense
- 6.e3D41 Pillsbury Variation
- 7.Bd3D42
The position after 7.Bd3
White has brought out the knight on c3, knight on f3 and bishop on d3; Black the knight on c6 and knight on d5. White has a half-open c-file; Black a half-open d-file. Black could capture with Nxc3, Nxd4, Nxe3, cxd4.
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| D46 | Semi-Slav Defense: Main Line | six squares: c4, c5, d5, c6, f6, d7 |
| D47 | Semi-Slav Defense: Semi-Meran Variation | seven squares: d3, c4, c5, d5, c6, f6, d7 |
| D45 | Semi-Slav Defense: Main Line | eight squares: f1, d3, c4, c5, d5, c6, f6, b8 |
| C06 | French Defense: Tarrasch Variation, Closed Variation, Main Line | nine squares: d2, e2, c3, e3, f3, c5, d5, e5 … |
| C09 | French Defense: Tarrasch Variation, Open System, Main Line | nine squares: f1, c2, d2, c3, d3, e3, d5, e6 … |
| D33 | Tarrasch Defense: Rubinstein System | nine squares: f1, e2, g2, d3, e3, g3, d5, e6 … |
| D40 | Queen’s Gambit Declined: Semi-Tarrasch Defense | nine squares: f1, e2, d3, e3, c4, d5, c6, f6 … |