Chess Openings Lab
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Italian Game: Two Knights Defense, Modern Bishop's Opening

The Modern Bishop's Opening line of the Two Knights is 4.d3, where White protects e4 and chooses a slow buildup. Black develops with ...Bc5 or ...Be7 and ...d6, and both sides maneuver for the d4 and d5 breaks rather than trading blows early.

Moves
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3
ECO
C55
Engine
+0.20 · level (Stockfish 17.1, depth 20)
Played
12,854 games in our lichess sample
White scores
53.5%

Key ideas for both sides

White

  • Build the c3-d3-e4 center with short castling, c3 and Re1, then aim for d4 when it is ready.
  • Play h3 to stop ...Bg4 or ...Ng4 before the knight on f3 is pinned.
  • Route the queen's knight via Nbd2 to f1 and g3, a slow but useful regrouping.
  • If Black plays ...a6 and ...Ba7, keep the light-squared bishop safe and consider Bb3.

Black

  • Develop with ...Bc5, ...d6 and ...h6, then castle and match White's slow plan.
  • ...a6 gives the bishop on c5 a safe retreat to a7 when White expands with d4 or b4.
  • ...Be7 is a calmer setup; it can lead to ...Bg4 and ...Bxf3 to fight for the d4 square.
  • Look for ...d5 when White's pieces are not ready, freeing Black's position in one move.

Plans and pawn structure

The structure is the quiet center: White's c3, d3 and e4 against Black's e5. White's main plan is d4 at the right moment, often after Re1, h3 and Nbd2. Another plan is a slow kingside buildup with Nf1-g3 and a later knight jump to f5. Black wants ...d5 or ...a6 with ...b5 for queenside space, and keeps pieces flexible for ...Be6 to trade White's strong bishop. Small advantages build up slowly.

Where the engine's main line heads: Quiet center: c3–d3–e4 against e5. A slow center: White has c3, d3 and e4 against e5. Nobody is in a hurry, and the d3–d4 break decides when the game opens.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.20: level. Its three top choices for Black:

  1. +0.20 4...Bc5 5.O-O d6 6.c3 h6 7.Re1
  2. +0.23 4...a6 5.O-O Bc5 6.c3 d6 7.Re1
  3. +0.26 4...Be7 5.Nc3 d6 6.a3 Bg4 7.h3

Pawns, from White's side.

How it scores on lichess

12,854 rated lichess games reached this position; White scored 53.5%.

under 120055.4%
1200–159953.2%
1600–199952.2%
2000 and up55.3%

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

Where it goes next

How to play against it

As Black, develop with ...Bc5 and ...d6, castle, and do not rush. Use ...h6 to keep White's bishop off g5, and prepare ...a6 so the bishop is not hit by d4. A quick ...d5 is fine if your pieces back it up.

Other lines with this name

The lichess opening list also files these lines under the same name, though they reach a different position: 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3 Be7; 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3 h6 5.O-O d6.

Questions

What are the moves of the Italian Game: Two Knights Defense, Modern Bishop's Opening?

The Italian Game: Two Knights Defense, Modern Bishop's Opening starts 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d3. Its ECO code is C55.

Is the Italian Game: Two Knights Defense, Modern Bishop's Opening good for White?

Stockfish 17.1 rates the position +0.20 at depth 20, which is level. In 12,854 lichess games from our sample, White scored 53.5%. A solid, low-risk choice for White players who prefer maneuvering, and Black must be patient and know the standard setups.

What is the main idea of the Italian Game: Two Knights Defense, Modern Bishop's Opening?

White avoids early tactics with d3 and plays for a slow d4 break later. Black develops with ...Bc5, ...d6 and castles, and both sides maneuver in a quiet center.

What should Black play next?

The engine's first choice is Bc5, with a6 and Be7 close behind. ...Bc5 puts the bishop on its most active square before White can play c3 and d4.

Updated October 2026. Sources and method.