Chess Opening Theory/1. f4

Bird's opening
	a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
	Position in Forsyth-Edwards Notation (FEN) rnbqkbnr/pppppppp/8/8/5P2/8/PPPPP1PP/RNBQKBNR
	Moves: 1. f4
	ECO code: A02-A03
	Parent: Starting position

1. f4 · Bird's opening

Bird's opening is an aggressive and less common first move. 1. f4 controls e5 from the flank, and means White will be able to soon play Nf3 without it keeping their f-pawn back. A danger in moving their f-pawn so soon is that it weakens White's kingside, and White must be aware of potential attacks on the e1-h4 diagonal.

1...d5, the Dutch variation, is the main line. Black takes space in the centre and controls e4, and the game resembles a Dutch defence in reverse.

Certainly White wishes to play 2. Nf3, developing while controlling h4. Then, a common plan for White is to adopt a reversed Leningrad Dutch set-up: 3. g3, 4. Bg2, and 5. O-O, and Black usually adopts a similar kingside fianchetto position also. White would like to play d3 and c3, or d3 and Qe1 to try for e4. Playing more in the manner of a stonewall Dutch, with 3. e3, 4. Be2, and d3 or d4, is an alternative.

1...Nf6, likewise controlling e5, usually transposes.

1...c5 allows 2. e4, and White reaches a more competitive Sicilian defence position, the McDonnell attack. However, it is more common for White to continue with the same Nf3, g3, Bg2, O-O approach, and only play e4 later if it is still available.

1...e5?!, From's gambit, offers the pawn to open lines of attack. It is an immediate attempt to exploit White's weakened kingside. Some famous "beginner" traps that stem from accepting the gambit include 2. fxe5 Qh4+!? 3. g3 Be7?, where Black sacrifices their queen as 4. gxh4?? Bxh4#; and 2. fxe5 d6 3. exd6 Bxd6 (a more sound way for Black to continue), where e.g. 4. e4?? Qh4+! and 5. g3?? leads to forced mate. White can decline the gambit (e.g. 2. e4, transposing to the king's gambit) but best is to accept it, and as long as White prevents infiltration of their position via h4 (2. fxe5 d6 3. exd6 Bxd6 4. Nf3!), they are better.

Other moves

1...f5, the symmetrical variation, may lead to a number of original gambits.
1...Nh6!? is called the Horsefly defence.

History

Bird's opening is named for Henry Bird (1829―1908), who helped to popularise it.

The earliest example of a game beginning 1. f4 was published Gioachino Greco's 1620 treatise. The game continued 1...e5, now known as From's gambit.^[1]

It was played occasionally in the first half of the 19th century, including in the 1834 matches between La Bourdonnais and McDonnell (something of a forerunner to the World Chess Championship), where the game transposed to a queen's pawn game.^[2] From 1856 Henry Bird began playing 1. f4 near exclusively with White, and had over 100 recorded games with it.^[3]

In the 20th century, Bent Larsen was known to play it, and 1. f4 received its highest level outing in Larsen v Fischer in the 1970-2 Candidates. Fischer played 1...c5 and the game transposed into something like the McDonnell attack.^[4]

1. f4 doesn't make many appearances in classical tournament chess today, though it is more common as a blitz weapon, played by the aggressive tactician who hopes to avoid theory and succeed by their wits alone.

Theory table

1. f4

	1	2	3	4
	f4 d5	Nf3 Nf6	e3 g6	Be2 Bg7	=
	... Nf6	Nf3 g6	e3 Bg7	Be2 O-O	=
	... e6	g4?? Qh4#	N/A N/A	N/A N/A	0-1
From Gambit	... e5	fxe5 d6	exd6 Bxd6	Nf3 Nf6	∞
Symmetric Variation	... f5					∞
	... g6	Nf3 d5	e3 Bg7	d4 Nh6	=