Kings Gambit Accepted: Mason, Keres & Requena Gambits

King’s Gambit Accepted (KGA)

Definition

The King’s Gambit Accepted is the branch of the King’s Gambit that arises after the moves 1. e4 e5 2. f4 exf4. Black “accepts” White’s offer of the f-pawn, grabbing material at the cost of allowing White a lead in development, an open f-file, and a potentially exposed black king. The opening belongs to ECO codes C30–C39.

Typical Plans and Ideas

  • White tries to seize the centre with d2–d4, accelerate piece activity, and launch a direct assault on f7 and the black king.
  • Black aims to consolidate the extra pawn, blunt White’s initiative (often by returning material later), and exploit the weaknesses created around White’s own king (e.g., the half-open g- and e-files).
  • Typical strategic levers: …g7–g5 (to keep the pawn on f4), …d7–d5 breaks, and rapid queenside castling.

Historical Significance

During the romantic era of chess (19th century) the KGA was the battleground for spectacular sacrificial games. Its popularity waned in the hyper-modern period, but it remains an excellent laboratory for studying initiative versus material. Boris Spassky revived it at top level in the 1960s, and it is still a favourite in blitz and bullet.

Illustrative Games

1. Adolf Anderssen – Lionel Kieseritzky, London 1851 (“The Immortal Game”) – perhaps the most famous sacrificial game ever played. 2. Boris Spassky – Robert Fischer, Mar del Plata 1960 – Spassky wins a model attacking game in the Bishop’s Gambit.

Interesting Facts

  • In 1962 Bobby Fischer wrote the famous article “A Bust to the King’s Gambit,” claiming that the line 1.e4 e5 2.f4 exf4 3.Nf3 d6! refuted the gambit. Modern engines disagree, but the article sparked decades of debate.
  • The ECO codes C37 and C38 cover Fischer’s recommended defence (the Fischer Defence), but the verdict remains “unclear.”
  • The KGA is one of the very few double-king-pawn openings in which Black scores above 50 % at master level because every tempo matters when the kings are so exposed.

Mason Gambit (in the King’s Gambit Accepted)

Definition

The Mason Gambit is an adventurous line introduced by the Irish-American master James Mason. It begins 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. h4 g4 5. Ne5!?

Concept

  • White deliberately places the knight on the seemingly precarious square e5, inviting …g4–g3 or …Qe7 to win the knight.
  • The real idea is the continuation 5…Nf6 6.d4. If Black captures on e4 or g3, White often sacrifices a second piece with Bxf4 or Bc4+, ripping open lines against the black king stuck in the centre.
  • The resulting positions teem with tactical resources; one inaccurate reply from Black can be fatal.

Theory & Evaluation

Modern engines give Black a small edge with perfect play, but over-the-board it is a dangerous surprise weapon – especially in rapid time controls.

Example Miniature

(Game fragment, White soon forces mate on the light squares.)

Trivia

  • Because it can arise directly after 4…g4, the Mason Gambit is sometimes catalogued as C35 in ECO.
  • James Mason employed the idea in casual games in the 1880s, but its first recorded tournament appearance was Mason – Bird, London 1887, where Black barely survived.

Keres Gambit (in the Falkbeer / King’s Gambit Complex)

Definition

Named after Estonian grandmaster Paul Keres, the Keres Gambit is Black’s pawn sacrifice in the Falkbeer Counter-Gambit: 1. e4 e5 2. f4 d5 3. exd5 c6!

How It Works

  1. Black immediately challenges the d5-pawn to open lines for both bishops and the queen.
  2. If White accepts with 4.dxc6, Black replies 4…Nxc6, achieving excellent piece play for the pawn.
  3. Alternatives such as 4.Nf3 or 4.d4 lead to complicated positions where Black keeps dynamic chances.

Strategic Significance

  • By returning the pawn, Black avoids the cramped structures typical of the Falkbeer and obtains rapid development.
  • The gambit is sound enough that modern theory considers it a fully playable counter to the King’s Gambit.

Model Game

Paul Keres – Vladimir Makogonov, USSR Ch. 1940, featured the line 4.d4 e4! after which Keres, playing White, admitted that Black’s piece activity fully compensated for the pawn.

Fun Facts

  • The Keres Gambit has also been tried against computers; it scores surprisingly well in bullet where precise defence is difficult for White.
  • Because it begins with 2…d5, it technically belongs to the King’s Gambit Declined, yet most databases file it under “KGA sidelines” for convenience.

Requena Gambit (Mason–Keres Hybrid)

Definition & Move Order

The Requena Gambit is an ultra-sharp offshoot of the Mason line, popularised by Spanish master José Manuel Requena in the 1990s. A typical move sequence is: 1. e4 e5 2. f4 exf4 3. Nf3 g5 4. h4 g4 5. Ne5 Nf6  6. Bc4 d5 7. exd5 Bd6 8. d4!?

Main Ideas

  • White offers a second pawn (and sometimes a minor piece) to rip open the e- and f-files.
  • A key tactical motif is Bxf4 followed by 0-0-0, swinging the rook to the third rank.
  • If Black castles kingside too early, the open diagonals b1-h7 and c1-h6 become killing lanes.

Theoretical Status

Because the Requena Gambit skirts the edge of soundness—engines give Black ≈ –1.00 with best defence— it is rare in classical chess but thrives in over-the-board blitz where memorisation and nerve outweigh objective evaluation.

Notable Encounter

Requena – Glez Rouco, Spanish Team Ch. 1998: after 8…Qe7 9.0-0 Black stumbled with 9…Nbd7?? and was mated in 19 moves.

Trivia

  • The line is sometimes indexed as “C35 Requena Gambit” in Spanish literature, though not officially recognised by ECO.
  • In online databases fewer than 200 master-level games reach move 8, making it one of the rarest sub-gambits of the King’s Gambit.
  • Requena himself reportedly coined the maxim “a second pawn is just another tempo” when asked about the gambit’s objective soundness.
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Last updated 2025-06-25