Three Knights Opening

ECO C46intermediate

After 1.e4 e5 2.Nf3 Nc6 3.Nc3, the natural 3...Nf6 gives the Four Knights and a reputation for dullness. The Three Knights covers everything else — 3...Bb4 pinning immediately, or 3...g6 heading for a fianchetto — and all of it is more interesting than the symmetrical alternative. Black is declining to copy, which means the position is unbalanced from move three and both sides have to think rather than recall. A practical choice for anyone tired of the Four Knights' drawn reputation.

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Main line

1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5 Nxe4 6.Qe2

Diagram shows the position after 6 half-moves of the main line. On SpeakChess you can drill this line move by move — the trainer plays the other side and corrects you instantly, then spaced repetition schedules each variation so you review it right before you would forget it.

Move by move

The first 11 moves of the main line, explained one at a time. Every move of every variation is annotated like this inside the trainer — this page shows the opening moves so you can judge the explanations before signing up.

1.e4 What a great way to begin! Your pawn marches up to e4, a light square right in the middle of the board. Owning the center early gives all your pieces room to come out and play. A strong, classic first step!
1...e5 Black answers boldly, pushing the pawn to e5 on a dark square. Now both sides have planted a pawn in the heart of the board. This balanced, fair fight for the center is how countless famous games have started.
2.Nf3 White moves their knight from g1 to f3. This is a good developing move that helps get your pieces into the game!
2...Nc6 Black moves their knight from b8 to c6. This is a good developing move, bringing a piece into the game.
3.Nc3 You move your knight from b1 to c3. This is a great developing move, bringing your knight out to a better square where it can help in the game.
3...Nf6 Black moves a knight from g8 to f6. This is a good developing move that helps bring a piece into the game.
4.a3 White moves a pawn from a2 to a3. It's a small step forward on the side of the board. This is a safe move that helps you control more space!
4...d5 Black advances the pawn from d7 to d5, challenging White's central pawn and increasing Black's own control of the center.
5.Bb5 White moves their bishop from f1 to b5. This is a good developing move, getting a strong piece into the game and ready for action!
5...Nxe4 Black moves their knight from f6 to e4, capturing a white pawn. This occupies a central square, increasing Black's control of the board.
6.Qe2 White moves their queen from her start place to e2. This is a good developing move, bringing a strong piece into the game.

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Win rates by rating

Results from real online games, measured after the line shown in each row. Most opening sites show one aggregate number — how an opening scores depends heavily on who is playing it.

Rating	Games	White wins	Draws	Black wins	Position after
400-600	32	68.8%	6.2%	25%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3
600-800	59	59.3%	8.5%	32.2%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5
800-1000	396	50.5%	2.8%	46.7%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5
1000-1200	97	49.5%	3.1%	47.4%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5
1200-1400	58	29.3%	1.7%	69%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5 Nxe4
1400-1600	64	28.1%	4.7%	67.2%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5 Nxe4
1600-1800	90	43.3%	4.4%	52.2%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5
1800-2000	113	44.2%	9.7%	46%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5
2000-2200	173	53.2%	4%	42.8%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5
2200-2400	53	39.6%	11.3%	49.1%	1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5 Nxe4 6.Qe2

Most played continuations (800-1000 rating)

After 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.a3 d5 5.Bb5:

dxe4 — played 35.1% of the time (White wins 47.5%, draws 4.3%, Black wins 48.2%)
d4 — played 21.7% of the time (White wins 50%, draws 1.2%, Black wins 48.8%)
Bd7 — played 16.2% of the time (White wins 50%, draws 0%, Black wins 50%)

Frequently asked questions

Is the Three Knights better than the Four Knights?

Not objectively, but often practically. The Four Knights is completely sound and has a well-earned reputation for symmetrical, balanced positions; the Three Knights unbalances things immediately at no real cost. If you want winning chances rather than equality, the difference matters.

What is the point of 3...Bb4?

It pins the knight on c3 and takes aim at e4, which is defended only by that knight. White must respond concretely rather than developing generally, and the resulting positions have a Nimzo-Indian flavour — a bishop traded for a knight, doubled pawns, and a long argument about whether that trade was good.

Is it suitable for beginners?

Yes. All of the moves are principled developing moves, so nothing has to be memorised to reach a decent position, and the resulting middlegames teach the same open-position skills the Italian does. It is a reasonable first departure from the most standard lines.