E04 Catalan Opening: Open Defense
E04 holds three named lines, all under the name Catalan Opening. It leaves E02, a position of the same name, with 5.Nf3. When the reference line ends, Black is one pawn up on material. White’s pieces and pawns attack four squares in Black’s half, level for the fewest of the 10 Catalan Opening codes. Black, to move in that position, has 35 legal moves, the second-highest count of the 10 Catalan Opening codes.
| # | White | Black |
|---|---|---|
| 1 | d4 | Nf6 |
| 2 | c4 | e6 |
| 3 | g3 | d5 |
| 4 | Bg2 | dxc4 |
| 5 | Nf3 |
The move that completes E04
The reference line of E05 plays all of these moves and continues beyond them; E04 is the position reached at 5.Nf3.
- 5.Nf3 The knight leaves g1 for f3, opening a line for the rook on h1.
Lines filed under E04
All three share the start 1.d4 Nf6 2.c4 e6 and then split two ways at White’s move 3.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| Catalan Opening: Open Defense | 3.g3 d5 4.Bg2 dxc4 5.Nf3 | 9 | Black +1 |
| Catalan Opening: Open Defense | 3.Nf3 d5 4.g3 c6 5.Bg2 dxc4 | 10 | Black +1 |
| Catalan Opening: Open Defense, Modern Sharp Variation | 3.g3 d5 4.Bg2 dxc4 5.Nf3 Nc6 6.Qa4 Bb4+ | 12 | Black +1, check |
Catalan Opening: Open Defense
- 3.Nf3 The knight leaves g1 for f3, opening a line for the rook on h1.
- 3...d5 The d-pawn advances two squares to d5, covering c4 and e4, opening a line for the bishop on c8 and the queen on d8.
- 4.g3 The g-pawn advances to g3, covering f4 and h4, opening a line for the bishop on f1.
- 4...c6 The c-pawn advances to c6, covering b5 and d5, opening a line for the queen on d8.
- 5.Bg2 The bishop leaves f1 for g2, opening a line for the rook on h1, guarding the rook on h1.
Catalan Opening: Open Defense, Modern Sharp Variation
- 3.g3 The g-pawn advances to g3, covering f4 and h4, opening a line for the bishop on f1.
- 3...d5 The d-pawn advances two squares to d5, covering c4 and e4, opening a line for the bishop on c8 and the queen on d8.
- 4.Bg2 The bishop leaves f1 for g2, guarding the rook on h1.
- 4...dxc4 The d-pawn takes the pawn on c4, covering b3 and d3, opening a line for the queen on d8.
- 5.Nf3 The knight leaves g1 for f3, opening a line for the rook on h1.
The road to E04
- 1.d4 … 3...d5five earlier stops: A40, A45, A50, E00
- 4.Bg2E01 Open Defense
- 4...dxc4E02 Open Defense
- 5.Nf3E04
The position after 5.Nf3
White has brought out the knight on f3 and bishop on g2; Black the knight on f6. White has a half-open c-file; Black a half-open d-file. Black could capture with Qxd4.
Codes that branch off from E04
The reference lines of one other code leave E04 from the position after 5.Nf3, each with its own moves.
| Code | Moves | Reference line |
|---|---|---|
| E05 | 5...Be7 | Catalan Opening: Open Defense, Classical Line |
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| E01 | Catalan Opening: Open Defense | four squares: g1, f3, c4, d5 |
| E06 | Catalan Opening: Closed | four squares: c4, d5, e7, f8 |
| D23 | Queen’s Gambit Accepted | five squares: f1, g2, g3, e6, e7 |
| D26 | Queen’s Gambit Accepted: Normal Variation, Traditional System | five squares: f1, e2, g2, e3, g3 |
| E10 | Indian Defense: Anti-Nimzo-Indian | five squares: f1, g2, g3, c4, d7 |
| A90 | Dutch Defense: Classical Variation | six squares: g1, f3, c4, f5, d7, f7 |
| E00 | Catalan Opening | six squares: f1, g1, g2, f3, c4, d7 |
Where lines continue from here
One named line filed under other codes passes through the position after 5.Nf3. It belongs to the code listed above.