King's Gambit

1.e4 e5 2.f4

You offer a pawn on move two and get the f-file, a big centre and a head start at their king in return. Under 1200 nobody knows how to hold the extra pawn, the positions are open and tactical, and you are the one who knows the plan.

Spar this opening

Your setup

Knightf3
Knighte5 / d3
Bishopc4 / e2 / d3
Bishopf4 / e3
Knightc3 / d2
Kingg1
Pawnse4 d4
CastleO-O

Nf3 before d4. Knight before centre. After 2...exf4 the diagonal from h4 to your king is open: 3.d4? Qh4+ and the king has to walk to e2, because g3 loses a second pawn. 3.Nf3 covers h4 and only then is d4 safe.

Ideas

You are buying the f-file

The pawn is gone. What you got is an open f-file, a d4 centre and time.

The King's Gambit is not about winning the pawn back. Once Black takes on f4 the f-file is half open for your rook, d4 comes with nothing to stop it, and Black has to spend moves keeping a pawn that is far from home. Spend your moves on development and the pawn tends to fall by itself.

Nf3 before anything

After ...exf4 the queen check on h4 is the only thing that can hurt you. Nf3 stops it.

With the f-pawn gone the e1–h4 diagonal is open, and ...Qh4+ either drives your king to e2 or costs you the g-pawn. 3.Nf3 covers h4 and attacks e5 at the same time. Bishop, centre pawn, other knight: all of it waits one move.

Against ...g5: h4 breaks the chain

The g5-pawn holds f4. Hit it with h4; after ...g4 your knight jumps to e5.

3...g5 is the honest way to keep the pawn, and it costs Black their king's cover. 4.h4 attacks the base of the chain. If Black plays ...g4 the knight is kicked to e5, where it eyes f7 and g4 and cannot easily be chased. If Black ignores it, hxg5 opens the h-file.

Against ...Bc5: never fxe5

The bishop on c5 is bait. Take on e5 and ...Qh4+ wins the game.

2...Bc5 declines the pawn and sets one trap: 3.fxe5?? Qh4+ and it is either mate on e4 or the rook on h1 goes. So Nf3 first, then Nc3, Bc4 and d3, and remember the c5-bishop also covers g1, so you cannot castle until you kick it with Na4 or block with Be3.

That bishop stops you castling

A black bishop on c5 looks straight at g1. Kick it before you plan O-O.

With your f-pawn gone the c5–g1 diagonal is wide open, so castling short is illegal while the bishop sits there. Na4 (from c3) hits it and either trades it or drives it to b6, where Nxb6 finishes the job. Only then does O-O come back.

Take f4 back on your terms

Bxf4 only when the pawn has no defenders. Until then, develop.

The f4-pawn is a liability for Black, not an asset: it needs ...g5 to hold it and ...g5 wrecks their king. Let them spend the moves. When the g-pawn has gone to g4 and the knight has moved from f6, Bxf4 recovers the pawn with tempo and your dark bishop lands on its best square.

When the book runs out

Develop toward f7. Open the f-file with a rook, then look for a sacrifice that is real.

Count pieces aimed at the king: knight on e5 or f3, bishop on c4, rook on f1, queen ready to come to f3 or g4. If you have more attackers than they have defenders, look for a hit on f7. If not, finish development and play d4 or e5. A King's Gambit played for the pawn is a King's Gambit lost.

The structure

The Kieseritzky picture: a pawn down, but the knight sits on e5 eyeing f7, d4 comes next, and Black's kingside pawns have all gone forward.

Traps

The check you forgot to stop

e4 e5 f4 exf4 d4 Qh4+ Ke2

The tell: The f-pawn is gone and the centre is begging for d4. Look at the h4–e1 diagonal first.

With the f-pawn off the board nothing covers h4. After 3.d4? Qh4+ the king has to go to e2, because 4.g3 fxg3 costs a second pawn and opens the king further. Nf3 covers h4, and only then is d4 safe. Every King's Gambit starts 3.Nf3 for this reason.

The poisoned pawn in the Declined

e4 e5 f4 Bc5 fxe5 Qh4+ Ke2 Qxe4#

The tell: Black declines with ...Bc5 and the e5-pawn looks free. The bishop on c5 is the tell: it covers g1, so your king has no escape.

3.fxe5 opens the h4–e1 diagonal and Black has the check at once. 4.Ke2 is mate on e4. 4.g3 Qxe4+ 5.Qe2 Qxh1 and the rook is gone. So 3.Nf3 first, always, and the pawn on e5 is left alone.

The knight sacrifice against ...f6

e4 e5 f4 exf4 Nf3 g5 h4 f6 Nxg5 fxg5 Qh5+ Ke7 Qxg5+

The tell: Black defends the g5-pawn with ...f6, opening the h5–e8 diagonal to their king.

The knight goes for two pawns and the king comes to e7 with no way back. After 7...Nf6 8.e5 the attack continues and Black's pieces are tied to the king. You are not up material, but the king in the centre is worth far more than a knight for two pawns here.

Model games

Kieseritzky: pawn back, king in the open

e4 e5 f4 exf4 Nf3 g5 h4 g4 Ne5 Nf6 d4 d6 Nd3 Nxe4 Bxf4 Bg7 c3 O-O Nd2

Nf3, h4, Ne5, d4, Nd3: the same moves every time. You are still a pawn down but Black's kingside is pawnless, your bishops are out and the e4-knight is about to be traded off.

Declined: kick the bishop, then castle

e4 e5 f4 Bc5 Nf3 d6 Nc3 Nf6 Bc4 Nc6 d3 Bg4 Na4 Bb6 Nxb6 axb6 O-O

Against ...Bc5 you never take on e5. Nf3, Nc3, Bc4, d3, then Na4 removes the bishop that was covering g1 and you castle into a healthy position.

Falkbeer: take and develop

e4 e5 f4 d5 exd5 exf4 Nf3 Nf6 Bc4 Nxd5 O-O Be7 d4 O-O Bxd5 Qxd5 Nc3

Black gives the pawn back to open the centre. You develop normally, castle, and trade the bishop for the knight when it kicks the queen around.

How the coach grades a move

Every move you play gets one of six grades, from the engine’s view of the position, with the book’s verdict taking over when it is harsher. The sentence beside it is always the reason. Tap it for what the move did, why this opening wants it, and whether anything was better.

Best: Nothing better was available.
Good: Within a few percent of best. Noise at this depth.
Playable: A small real gap. The better move is named, play goes on.
Inaccuracy: Seven to twelve points of winning chances. The game stops to show you.
Mistake: Twelve or more, or a move the book warns against, or a broken order rule.
Blunder: Twenty-five or more. Usually material.

Catalogued as C30–C39 in the Encyclopaedia of Chess Openings, the reference index most databases sort by.