Chess Opening Theory/1. e4/1...e5/2. Nf3


King's Knight Opening
a b c d e f g h
8a8 black rookb8 black knightc8 black bishopd8 black queene8 black kingf8 black bishopg8 black knighth8 black rook8
7a7 black pawnb7 black pawnc7 black pawnd7 black pawne7 black kingf7 black pawng7 black pawnh7 black pawn7
6a6 black kingb6 black kingc6 black kingd6 black kinge6 black kingf6 black kingg6 black kingh6 black king6
5a5 black kingb5 black kingc5 black kingd5 black kinge5 black pawnf5 black kingg5 black kingh5 black king5
4a4 black kingb4 black kingc4 black kingd4 black kinge4 white pawnf4 black kingg4 black kingh4 black king4
3a3 black kingb3 black kingc3 black kingd3 black kinge3 black kingf3 white knightg3 black kingh3 black king3
2a2 white pawnb2 white pawnc2 white pawnd2 white pawne2 black kingf2 white pawng2 white pawnh2 white pawn2
1a1 white rookb1 white knightc1 white bishopd1 white queene1 white kingf1 white bishopg1 black kingh1 white rook1
a b c d e f g h
Position in Forsyth-Edwards Notation (FEN)
Moves: 1. e4 e5 2. Nf3
Responses:

2. Nf3 - King's Knight Opening

edit

The King's Knight Opening is the most common opening played in chess. By developing a knight to f3, White attacks Black's e-pawn and fights for control of the center.

Black responses

edit

Black's typical response to 2. Nf3 is either 2...Nc6, defending their valuable e5 pawn, or 2...Nf6, challenging White's e4 pawn (the Petrov Defense). Each choice leads to different types of positions and strategies.

a b c d e f g h
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
a b c d e f g h
2...Nc6   (King's Knight, main line)

2...Nc6 is the natural move, combining defence of the pawn with control of the d4 square and avoiding committing another pawn for now. 2. Nf3 is 10 times more popular than everything else combined, and in turn the reply 2...Nc6 is about 5 times more popular than everything else combined.

Common Continuations for White after 1. e4 e5 2. Nf3 Nc6:

  • 3. Bb5 (Ruy Lopez): A classical approach aiming to exert pressure on Black's center and knight on c6.
  • 3. Bc4 (Italian Game): Targets f7, the weakest point in Black's camp, and supports White's central pawns.
  • 3. d4 (Scotch Opening): Aiming for rapid development and opening of the center.
  • 3. Nc3 (Three Knights' Opening): Develops another piece while keeping central tension.
  • 3. c3 (Ponziani Opening): Prepares to support the d4 push, challenging Black's central pawn structure.
a b c d e f g h
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
a b c d e f g h
2...d6   (Philidor)

2...d6, Philidor's Defence, is the other safe option to defend the pawn.

It restricts Black's dark-squared bishop to the e7-square, and grants White an advantage in territory, but it builds a fortress that cannot be easily battered down. This is generally considered an inferior way to defend the e5 pawn because white can easily push for advantage here, and white gets a 58% score here, with 41% wins opposed to Black's 25%. This is especially the case if Black makes a ...c7-c5 push to kick a potential knight on d4, greatly weakening the d6-pawn.

An alternative (older) way to play this is to follow up with 3...f5, but more recent analyses have proven this line to be completely losing for Black

a b c d e f g h
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
a b c d e f g h
2...f6?   (Damiano)

Note that 2...f6? is a bad move.

2...f6 is known as the Damiano Defence. It is a poor move as it weakens black's kingside and deprives the knight on g8 of its most natural development square. Additionally, it does not even defend the pawn; if 2...Nxe5, fxe5 allows Qh5+, after which black either loses a rook (3... g6 4. Qxe5+) or is hunted into the center of the board with 3...Ke7 4. Qxe5+. Even the person for who the "defence" is named after, Pedro Damiano, condemned the defense as weak and inferior.

Challenging the White pawn

edit
a b c d e f g h
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
a b c d e f g h
2...Nf6   (Petrov)

2...Nf6 is the Petrov Defence.

Black wants the same things that White wants, but once again White will be back in a symmetrical position with the advantage of moving first. This opening is known to be notoriously drawish due to the resultant symmetric positions.

a b c d e f g h
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
a b c d e f g h
2...f5   (Latvian Gambit)

2...f5 is the Latvian Gambit.

This iconic counter-thrust divides opinion like very few other openings.

Has Black lured White into a minefield of tricks and traps leading to an inevitable violent death?

Or has Black given away a pawn for nothing?

a b c d e f g h
8        8
7        7
6        6
5        5
4        4
3        3
2        2
1        1
a b c d e f g h
2...d5   (Elephant Gambit)

2...d5 is the Elephant Gambit.

It's along the same lines as the Latvian, but less complex – White needs to do less memorising to reach a good position.


Statistics

edit

Estimated next move popularity.

Nc6 83.5%, Nf6 11%, d6 4%, f5 0.5%, other less than 0.5%.

Theory table

edit

For explanation of theory tables, see theory table and for notation, see algebraic notation.

1. e4 e5 2. Nf3

2 3 4 5
Ruy Lopez ...
Nc6
Bb5
a6
Ba4
Nf6
O-O
Be7
=
Petrov's Defence ...
Nf6
Nxe5
d6
Nf3
Nxe4
d4
d5
=
Philidor Defence ...
d6
d4
exd4
Nxd4
Nf6
Nc3
Be7
+=
Latvian Gambit ...
f5
Nxe5
Qf6
d4
d6
Nc4
fxe4
+/-
Elephant Gambit ...
d5
exd5
Bd6
d4
e4
Ne5
Nf6
+=
Câmara Defence ...
Qe7
Bc4
d6
O-O
g6
d4
Bg7
+=
Greco Defence ...
Qf6
Bc4
Qg6
Nc3 +/-
Damiano Defence ...
f6?
Nxe5! +/-

When contributing to this Wikibook, please follow the Conventions for organization.

References

edit
  • Nunn's Chess Openings. 1999. John Nunn (Editor), Graham Burgess, John Emms, Joe Gallagher. ISBN 1-8574-4221-0.