Chess Openings Lab
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Ruy Lopez: Morphy Defense, Classical Defense Deferred

The Classical Defense Deferred is 4.Ba4 Bc5, where Black plays the active bishop move after inserting ...a6 and Ba4. White builds with c3 and d4, while Black can retreat to a7 and use the ...b5 option against the a4 bishop.

Moves
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Bc5
ECO
C70
Engine
+0.44 · a slight edge for White (Stockfish 17.1, depth 20)
Played
710 games in our lichess sample
White scores
49.9%

Key ideas for both sides

White

  • Play c3 and d4, as in the top engine line, gaining time on the c5 bishop.
  • Castle first and then play c3 and d4, keeping the center strong.
  • Use h3 and d3 for a slower setup if Black prefers ...Nf6.

Black

  • Develop with ...Nge7 and ...Ng6, retreating the bishop to a7 when d4 comes.
  • Use ...b5 to push the bishop to b3 before White's center arrives.
  • Castle quickly and keep the bishop on the a7-g1 diagonal aimed at f2.

Plans and pawn structure

White plays c3 and d4, and Black's bishop goes to a7 or b6. Black uses ...b5 to gain queenside space and push the a4 bishop back to b3. White aims for a central space edge with d4 and Re1. Black develops with ...Nge7 and ...Ng6 or ...Nf6, keeping e5 solid. The structure becomes central tension with d4 and e4 against e5, and the a7 bishop presses d4 and f2.

Where the engine's main line heads: Central tension: d4 and e4 against e5. Central tension: d4 and e4 against e5. One capture changes the character of the game.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.44: a slight edge for White. Its three top choices for White:

  1. +0.44 5.c3 Nge7 6.O-O Ba7 7.d4 Ng6
  2. +0.40 5.O-O b5 6.Bb3 d6 7.c3 Nf6
  3. +0.21 5.h3 Nf6 6.d3 d6 7.c3 Bd7

Pawns, from White's side.

How it scores on lichess

710 rated lichess games reached this position; White scored 49.9%.

under 120047.6%
1200–159950.0%
1600–199949.5%
2000 and up51.1%

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

How to play against it

As White, play c3 and d4 to gain time on the bishop, and castle before opening lines. As Black, retreat to a7 when d4 arrives, use ...b5 to gain queenside space, and castle quickly so White's central break does not catch your king.

Questions

What are the moves of the Ruy Lopez: Morphy Defense, Classical Defense Deferred?

The Ruy Lopez: Morphy Defense, Classical Defense Deferred starts 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Bc5. Its ECO code is C70.

Is the Ruy Lopez: Morphy Defense, Classical Defense Deferred good for Black?

Stockfish 17.1 rates the position +0.44 at depth 20, which is a slight edge for White. In 710 lichess games from our sample, White scored 49.9%. An active, flexible choice for Black; White gets a classical central edge.

What is the main idea of the Ruy Lopez: Morphy Defense, Classical Defense Deferred?

Black develops the bishop to c5 after ...a6 and Ba4. White builds a center with c3 and d4, and Black retreats to a7 while using ...b5.

What should White play next?

The engine's first choice is c3, with O-O and h3 close behind. 5.c3 prepares d4 to gain time against the c5 bishop.

Updated October 2026. Sources and method.