D15 Slav Defense: Three Knights Variation
D15 holds ten named lines, all under the name Slav Defense. It leaves D11 (Slav Defense: Modern Line) with 3...Nf6 4.Nc3. With ten named lines it is the largest code of the 10 Slav Defense codes. Lines of 11 other codes continue from its position, the third-widest spread of the 10 Slav Defense codes. Material is no longer level at the end of four of its lines; the widest gap, one pawn in Black’s favour, comes in Slav Defense: Alekhine Variation.
| # | White | Black |
|---|---|---|
| 1 | d4 | d5 |
| 2 | c4 | c6 |
| 3 | Nf3 | Nf6 |
| 4 | Nc3 |
The move that completes D15
The reference line of D16 plays all of these moves and continues beyond them; D15 is the position reached at 4.Nc3.
- 4.Nc3 The knight leaves b1 for c3, opening a line for the rook on a1.
Lines filed under D15
All ten share their first seven plies, the whole reference line and then split four ways at Black’s move 4.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| Slav Defense: Three Knights Variation | (the shared start itself) | 7 | |
| Slav Defense: Chebanenko Variation | 4...a6 | 8 | |
| Slav Defense: Schlechter Variation | 4...g6 | 8 | |
| Slav Defense: Süchting Variation | 4...Qb6 | 8 | |
| Slav Defense: Two Knights Attack | 4...dxc4 | 8 | Black +1 |
| Slav Defense: Alekhine Variation | 4...dxc4 5.e3 | 9 | Black +1 |
| Slav Defense: Chebanenko Variation, Advance System | 4...a6 5.c5 | 9 | |
| Slav Defense: Geller Gambit | 4...dxc4 5.e4 | 9 | Black +1 |
| Slav Defense: Chebanenko Variation | 4...a6 5.e3 Bf5 | 10 | |
| Slav Defense: Geller Gambit | 4...dxc4 5.e4 b5 6.e5 | 11 | Black +1 |
The road to D15
- 1.d4 … 2.c4three earlier stops: A40, D00, D06
- 2...c6D10 Slav Defense
- 3.Nf3D11 Modern Line
- 4.Nc3D15
The position after 4.Nc3
White has brought out the knight on c3 and knight on f3; Black the knight on f6. Black could capture with dxc4. Undefended and attacked: the pawn on c4. Black is to move and has 31 legal moves.
Codes that branch off from D15
The reference lines of two other codes leave D15 from two of its named positions; “From” gives the last part of that position’s name.
| Code | From | Moves | Reference line |
|---|---|---|---|
| D16 | Two Knights Attack | 5.a4 | Slav Defense: Alapin Variation |
| D43 | Three Knights Variation | 4...e6 | Semi-Slav Defense |
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| D13 | Slav Defense: Exchange Variation | four squares: b1, c3, c4, c6 |
| D24 | Queen’s Gambit Accepted: Showalter Variation | four squares: c4, d5, c6, c7 |
| D37 | Queen’s Gambit Declined: Three Knights Variation | four squares: c6, e6, c7, e7 |
| D40 | Queen’s Gambit Declined: Semi-Tarrasch Defense | four squares: c5, c6, e6, e7 |
| D45 | Semi-Slav Defense: Main Line | four squares: e2, e3, e6, e7 |
| D90 | Grünfeld Defense: Three Knights Variation | four squares: c6, g6, c7, g7 |
| A31 | English Opening: Symmetrical Variation, Anti-Benoni Variation | six squares: b1, c3, c5, d5, c6, d7 |
Where lines continue from here
Besides the codes above, they belong to D17, D18, D19, D44, D45, D47, D48, D49, D52.
Other move orders
- Slav Defense: Three Knights Variation is also reached inside D45 Semi-Slav Defense: Stonewall Defense, whose order is 1.d4 d5 2.Nf3 Nf6 3.c4 c6 4.Nc3.
- Slav Defense: Three Knights Variation is also reached inside D49 Semi-Slav Defense: Meran Variation, Rellstab Attack, whose order is 1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.Nf3.