C39 King’s Gambit Accepted: King’s Knight’s Gambit
C39 holds 30 named lines, all under the name King’s Gambit. It leaves C34, a position of the same name, with 4.h4. When the reference line ends, Black is one pawn up on material. Its deepest line, King’s Gambit Accepted: Allgaier, Cook Variation, runs to 10.Be5+, the second-longest of the 10 King’s Gambit codes. With 30 named lines it is the fourth-largest code of the 10 King’s Gambit codes.
| # | White | Black |
|---|---|---|
| 1 | e4 | e5 |
| 2 | f4 | exf4 |
| 3 | Nf3 | g5 |
| 4 | h4 |
Moves only C39 plays
Same as C37 up to 3...g5, then:
- 4.h4 The h-pawn advances two squares to h4, covering g5, opening a line for the rook on h1.
Lines filed under C39
All 30 share their first seven plies, the whole reference line.
| Name | After the shared start | Plies | At the end |
|---|---|---|---|
| King’s Gambit Accepted: King’s Knight’s Gambit | (the shared start itself) | 7 | Black +1 |
| King’s Gambit Accepted: Allgaier Gambit | 4...g4 5.Ng5 | 9 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit | 4...g4 5.Ne5 | 9 | Black +1 |
| King’s Gambit Accepted: Allgaier, Schlechter Defense | 4...g4 5.Ng5 Nf6 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Berlin Defense | 4...g4 5.Ne5 Nf6 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Brentano Defense | 4...g4 5.Ne5 d5 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Kolisch Defense | 4...g4 5.Ne5 d6 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Long Whip | 4...g4 5.Ne5 h5 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Neumann Defense | 4...g4 5.Ne5 Nc6 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Paulsen Defense | 4...g4 5.Ne5 Bg7 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Rosenthal Defense | 4...g4 5.Ne5 Qe7 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky, Polerio Defense | 4...g4 5.Ne5 Be7 | 10 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Berlin Defense, Rubinstein Variation | 4...g4 5.Ne5 Nf6 6.d4 | 11 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Cotter Gambit | 4...g4 5.Ng5 h6 6.Nxf7 | 11 | |
| King’s Gambit Accepted: Kieseritzky Gambit, Berlin Defense, de Riviere Variation | 4...g4 5.Ne5 Nf6 6.Nxg4 d5 | 12 | |
| King’s Gambit Accepted: Allgaier Gambit, Thorold Attack | 4...g4 5.Ng5 h6 6.Nxf7 Kxf7 7.d4 | 13 | Black +3 |
| King’s Gambit Accepted: Allgaier Gambit, Urusov Attack | 4...g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Bc4+ | 13 | Black +3, check |
| King’s Gambit Accepted: Allgaier, Blackburne Gambit | 4...g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Nc3 | 13 | Black +3 |
| King’s Gambit Accepted: Kieseritzky Gambit, Brentano Defense | 4...g4 5.Ne5 d5 6.d4 Nf6 7.Bxf4 | 13 | |
| King’s Gambit Accepted: Kieseritzky, Salvio Defense, Cozio Variation | 4...g4 5.Ne5 Qe7 6.d4 f5 7.Bc4 | 13 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Anderssen Defense | 4...g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 | 14 | |
| King’s Gambit Accepted: Kieseritzky Gambit, Paulsen Defense Deferred | 4...g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bg7 | 14 | |
| King’s Gambit Accepted: Kieseritzky Gambit, Brentano Defense, Caro Variation | 4...g4 5.Ne5 d5 6.d4 Nf6 7.Bxf4 Nxe4 8.Nd2 | 15 | Black +1 |
| King’s Gambit Accepted: Kieseritzky, Long Whip Defense, Jaenisch Variation | 4...g4 5.Ne5 h5 6.Bc4 Rh7 7.d4 Bh6 8.Nc3 | 15 | Black +1 |
| King’s Gambit Accepted: Kieseritzky, Rice Gambit | 4...g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.O-O | 15 | White castled |
| King’s Gambit Accepted: Allgaier, Horny Defense | 4...g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Qxg4 Nf6 8.Qxf4 Bd6 | 16 | Black +1 |
| King’s Gambit Accepted: Kieseritzky Gambit, Rice Gambit | 4...g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.O-O Bxe5 | 16 | Black +3, White castled |
| King’s Gambit Accepted: Allgaier, Urusov Attack | 4...g4 5.Ng5 h6 6.Nxf7 Kxf7 7.Bc4+ d5 8.Bxd5+ Kg7 9.d4 | 17 | Black +2 |
| King’s Gambit Accepted: Kieseritzky Gambit, Anderssen-Cordel Gambit | 4...g4 5.Ne5 Nf6 6.Bc4 d5 7.exd5 Bd6 8.d4 Nh5 9.Bxf4 Nxf4 | 18 | Black +2 |
| King’s Gambit Accepted: Allgaier, Cook Variation | 4...g4 5.Ng5 h6 6.Nxf7 Kxf7 7.d4 d5 8.Bxf4 dxe4 9.Bc4+ Kg7 10.Be5+ | 19 | Black +3, check |
The road to C39
- 1.e4 … 2...exf4four earlier stops: B00, C20, C30, C33
- 3.Nf3C34 King’s Knight’s Gambit
- 3...g5C34 King’s Knight’s Gambit
- 4.h4C39
The position after 4.h4
White has brought out the knight on f3; Black has not yet moved a knight or bishop. White has a half-open f-file; Black a half-open e-file. Black could capture with gxh4. Black is to move and has 29 legal moves.
Closest boards in other codes
| Code | Line | Differs on |
|---|---|---|
| C33 | King’s Gambit Accepted | six squares: g1, h2, f3, h4, g5, g7 |
| C35 | King’s Gambit Accepted: Cunningham Defense | six squares: h2, h4, g5, e7, g7, f8 |
| C36 | King’s Gambit Accepted: Modern Defense | six squares: h2, h4, d5, g5, d7, g7 |
| C38 | King’s Gambit Accepted: Traditional Variation | six squares: f1, h2, c4, h4, g7, f8 |
| C40 | King’s Knight Opening | seven squares: f2, h2, f4, h4, e5, g5, g7 |
| C30 | King’s Gambit | eight squares: g1, h2, f3, f4, h4, e5, g5, g7 |
| A04 | Zukertort Opening | nine squares: e2, f2, h2, e4, f4, h4, g5, e7 … |