Chess Openings Lab
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Sicilian Defense: Four Knights Variation

The Sicilian Four Knights is 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Nf6, with all four knights out early. Black hopes for ...Bb4 pinning the c3 knight and hitting e4, while White wants to use the knight trade on c6 and the e5 push to gain space.

Moves
1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Nf6
ECO
B45
Engine
+0.32 · a slight edge for White (Stockfish 17.1, depth 20)
Played
3,327 games in our lichess sample
White scores
47.5%

Key ideas for both sides

White

  • 6.Nxc6 bxc6 7.e5 drives the f6 knight to d5, then Ne4 and f4 build a kingside space edge.
  • Ndb5 eyes d6 and asks Black to find ...Bb4 or ...d6 quickly.
  • 6.Bf4 hits d6 at once and pairs well with Bb5 to pin the c6 knight.
  • Calm 6.Be2 with Be3 and O-O leads to Scheveningen-style positions with a solid king.

Black

  • ...Bb4 pins the c3 knight and adds pressure on e4; it is Black's main resource.
  • After Nxc6 bxc6 e5 Nd5, the knight is strong on d5. Use ...Qc7 or ...Qa5+ to hit e5.
  • Against Bf4 lines, ...d6 and ...e5 can gain time on the bishop.
  • Keep ...d5 in mind. It frees the c8 bishop and challenges White's e4 pawn.

Plans and pawn structure

With knights on c6 and f6, Black is ready to play ...Bb4 and ...d5, so White often acts first. The trade on c6 and the e5 push give White space and a target on c6, but Black gets a strong knight on d5 and an open b-file. If White chooses Ndb5, the d6 square becomes the focus and Black must cover it with ...Bb4 or ...d6. Slower setups with Be2 and Be3 let Black reach a solid Scheveningen.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.32: a slight edge for White. Its three top choices for White:

  1. +0.32 6.Nxc6 bxc6 7.e5 Nd5 8.Ne4 Qc7
  2. +0.25 6.Bf4 d6 7.Bb5 Bd7 8.Nxc6 bxc6
  3. +0.24 6.Be2 Qc7 7.Be3 a6 8.O-O Be7

Pawns, from White's side.

How it scores on lichess

3,327 rated lichess games reached this position; White scored 47.5%.

under 120059.5%
1200–159946.2%
1600–199944.9%
2000 and up50.7%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

Where it goes next

How to play against it

With White, the trade on c6 followed by e5 is the clearest plan. Then Ne4 and f4 support the pawn and keep the d5 knight from settling. Do not leave e4 loose while ...Bb4 is possible, since the pin plus a capture on e4 can cost a pawn.

Questions

What are the moves of the Sicilian Defense: Four Knights Variation?

The Sicilian Defense: Four Knights Variation starts 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 Nf6. Its ECO code is B45.

Is the Sicilian Defense: Four Knights Variation good for Black?

Stockfish 17.1 rates the position +0.32 at depth 20, which is a slight edge for White. In 3,327 lichess games from our sample, White scored 47.5%. Suits Black players who like active piece play; White should know the Nxc6 and e5 plan to get an edge.

What is the main idea of the Sicilian Defense: Four Knights Variation?

Black develops both knights quickly and plans ...Bb4 to pin and press e4. White often trades on c6 and pushes e5 to gain space and leave Black with a split pawn on c6.

What should White play next?

The engine's first choice is Nxc6, with Bf4 and Be2 close behind. 6.Nxc6 bxc6 7.e5 forces the f6 knight away and gains space in the center.

Updated October 2026. Sources and method.