B03 Alekhine Defense
B03 holds 18 named lines, all under the name Alekhine Defense. It leaves B02 (Alekhine Defense: Normal Variation) with 3.d4. Queenside castling appears once among its lines, in Alekhine Defense: Four Pawns Attack, Tartakower Variation. Material is no longer level at the end of two of its lines; the widest gap, one pawn in White’s favour, comes in Alekhine Defense: Exchange Variation.
| # | White | Black |
|---|---|---|
| 1 | e4 | Nf6 |
| 2 | e5 | Nd5 |
| 3 | d4 |
The move that completes B03
The reference line of B04 plays all of these moves and continues beyond them; B03 is the position reached at 3.d4.
- 3.d4 The d-pawn advances two squares to d4, covering c5 and e5, opening a line for the bishop on c1 and the queen on d1.
Lines filed under B03
All 18 share their first five plies, the whole reference line and then split two ways at Black’s move 3.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| Alekhine Defense | (the shared start itself) | 5 | |
| Alekhine Defense | 3...d6 | 6 | |
| Alekhine Defense: O’Sullivan Gambit | 3...b5 | 6 | |
| Alekhine Defense | 3...d6 4.c4 | 7 | |
| Alekhine Defense: Balogh Variation | 3...d6 4.Bc4 | 7 | |
| Alekhine Defense: Exchange Variation | 3...d6 4.c4 Nb6 5.exd6 | 9 | White +1 |
| Alekhine Defense: Four Pawns Attack | 3...d6 4.c4 Nb6 5.f4 | 9 | |
| Alekhine Defense: Hunt Variation | 3...d6 4.c4 Nb6 5.c5 | 9 | |
| Alekhine Defense: Four Pawns Attack, Cambridge Gambit | 3...d6 4.c4 Nb6 5.f4 g5 | 10 | |
| Alekhine Defense: Four Pawns Attack, Fianchetto Variation | 3...d6 4.c4 Nb6 5.f4 g6 | 10 | |
| Alekhine Defense: Four Pawns Attack, Trifunovic Variation | 3...d6 4.c4 Nb6 5.f4 Bf5 | 10 | |
| Alekhine Defense: Modern Variation, Alekhine Gambit | 3...d6 4.c4 Nb6 5.Nf3 Bg4 6.Be2 | 11 | |
| Alekhine Defense: Four Pawns Attack, Main Line | 3...d6 4.c4 Nb6 5.f4 dxe5 6.fxe5 Nc6 7.Be3 | 13 | |
| Alekhine Defense: Exchange Variation, Voronezh Variation | 3...d6 4.c4 Nb6 5.exd6 cxd6 6.Nc3 g6 7.Be3 Bg7 8.Rc1 O-O 9.b3 | 17 | Black castled |
| Alekhine Defense: Four Pawns Attack, Ilyin-Zhenevsky Variation | 3...d6 4.c4 Nb6 5.f4 dxe5 6.fxe5 Nc6 7.Nf3 Bg4 8.e6 fxe6 9.c5 | 17 | Black +1 |
| Alekhine Defense: Four Pawns Attack, Korchnoi Variation | 3...d6 4.c4 Nb6 5.f4 dxe5 6.fxe5 Bf5 7.Nc3 e6 8.Nf3 Be7 9.Be2 O-O 10.O-O f6 | 20 | both castled |
| Alekhine Defense: Exchange Variation, Karpov Variation | 3...d6 4.c4 Nb6 5.exd6 cxd6 6.Nc3 g6 7.h3 Bg7 8.Nf3 O-O 9.Be2 Nc6 10.O-O Bf5 11.Bf4 | 21 | both castled |
| Alekhine Defense: Four Pawns Attack, Tartakower Variation | 3...d6 4.c4 Nb6 5.f4 dxe5 6.fxe5 Nc6 7.Be3 Bf5 8.Nc3 e6 9.Nf3 Qd7 10.Be2 O-O-O 11.O-O Be7 | 22 | both castled |
The road to B03
- 1.e4one earlier stop: B00
- 1...Nf6B02 Alekhine Defense
- 2...Nd5B02 Normal Variation
- 3.d4B03
The position after 3.d4
Black has brought out the knight on d5; White has not yet moved a knight or bishop. Black is to move and has 23 legal moves.
Codes that branch off from B03
The reference lines of one other code leave B03 from the position after 3...d6, each with its own moves.
| Code | Moves | Reference line |
|---|---|---|
| B04 | 4.Nf3 | Alekhine Defense: Modern Variation |
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| A40 | Queen’s Pawn Game | four squares: e2, d5, e5, g8 |
| A45 | Indian Defense | four squares: e2, d5, e5, f6 |
| C02 | French Defense: Advance Variation | five squares: d5, e6, d7, e7, g8 |
| D00 | Queen’s Pawn Game | five squares: e2, d5, e5, d7, g8 |
| A41 | Queen’s Pawn Game | six squares: e2, d5, e5, d6, d7, g8 |
| A43 | Benoni Defense: Old Benoni | six squares: e2, c5, d5, e5, c7, g8 |
| A46 | Indian Defense: Knights Variation | six squares: g1, e2, f3, d5, e5, f6 |
Where lines continue from here
Eleven named lines filed under other codes pass through the position after 3.d4. Besides the codes above, they belong to B05.