Chess Openings Lab
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Ruy Lopez: Morphy Defense, Caro Variation

The Caro Variation is 4.Ba4 b5, where Black pushes the bishop back at once before developing the kingside. White must retreat with Bb3, while Black puts the bishop on b7 and plays ...Nf6, ...Bc5 or ...Na5 to hunt the b3 bishop.

Moves
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5
ECO
C70
Engine
+0.42 · a slight edge for White (Stockfish 17.1, depth 20)
Played
2,225 games in our lichess sample
White scores
56.9%

Key ideas for both sides

White

  • Retreat with Bb3 at once; moves like d4 or c3 lose the bishop to ...bxa4.
  • Castle and play Re1 and c3, building a classical center before pushing d4.
  • Use a4 to attack the b5 pawn and open the a-file for the rook.

Black

  • Play ...Bb7 and ...Nf6, aiming at the e4 pawn along the long diagonal.
  • Develop the dark bishop to c5 and then b6, keeping pressure on f2.
  • Use ...Na5 to trade off White's strong b3 bishop when it suits you.

Plans and pawn structure

After Bb3, Black develops with ...Bb7, ...Nf6 and ...Bc5. White castles, plays Re1 and c3, then aims for d4. Black's bishops on b7 and c5 aim at the center and the white king. White's a4 break targets the b5 pawn and can open the a-file. The Noah's Ark Trap is a danger: if White plays d4 carelessly, ...c5 and ...c4 can trap the b3 bishop.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.42: a slight edge for White. Its three top choices for White:

  1. +0.42 5.Bb3 Bb7 6.O-O Nf6 7.Re1 Bc5
  2. −3.38 5.d4 bxa4 6.d5 Nce7 7.Nxe5 Ng6
  3. −3.72 5.c3 bxa4 6.Qxa4 Nf6 7.d4 Bd6

Pawns, from White's side.

How it scores on lichess

2,225 rated lichess games reached this position; White scored 56.9%.

under 120057.1%
1200–159960.9%
1600–199952.4%
2000 and up56.1%

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

Where it goes next

How to play against it

As White, retreat with Bb3 immediately, since anything else loses the bishop to ...bxa4. Watch for ...Na5 and ...c5 ideas around the b3 bishop. As Black, develop with ...Bb7 and ...Nf6, keep pressure on e4, and castle before opening lines.

Questions

What are the moves of the Ruy Lopez: Morphy Defense, Caro Variation?

The Ruy Lopez: Morphy Defense, Caro Variation starts 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 b5. Its ECO code is C70.

Is the Ruy Lopez: Morphy Defense, Caro Variation good for Black?

Stockfish 17.1 rates the position +0.42 at depth 20, which is a slight edge for White. In 2,225 lichess games from our sample, White scored 56.9%. A sharp, active choice for Black; White must retreat precisely and avoid traps.

What is the main idea of the Ruy Lopez: Morphy Defense, Caro Variation?

Black pushes ...b5 early to drive the bishop to b3, then develops with ...Bb7 and ...Bc5. White must retreat at once and build a classical center.

What should White play next?

The engine's first choice is Bb3, with d4 and c3 close behind. 5.Bb3 retreats at once, since other moves lose the bishop to ...bxa4.

Updated October 2026. Sources and method.