Chess Openings Lab
a8b7c6d5e4f3g2h1

Sicilian Defense: Smith-Morra Gambit Accepted, Pin Defense

The Pin Defense of the Smith-Morra is 4...Nc6 5.Nf3 e6 6.Bc4 Bb4, where Black pins the c3 knight and threatens to take it. White wants to castle and accept doubled pawns after ...Bxc3 for the bishop pair and open lines, while Black hopes to blunt White's activity with ...Nge7 and ...d5.

Moves
1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 Bb4
ECO
B21
Engine
−0.31 · a slight edge for Black (Stockfish 17.1, depth 20)
Played
575 games in our lichess sample
White scores
48.5%

Key ideas for both sides

White

  • Castle with 7.O-O; after ...Bxc3, recapture bxc3 and use the bishop pair and the open b-file.
  • Play Bf4 to cover d6, then push e5 if Black's knight comes to f6.
  • Qe2 and Rd1 build pressure on the d-file when Black keeps the bishop on b4.

Black

  • Develop with ...Nge7, then trade on c3 and strike with ...d5 to open the center on your terms.
  • After ...Nf6 and e5, the knight can jump to e4 and add pressure on c3.
  • Use ...Ng6 to fight for e5 and f4, especially after Qe2 and Rd1.

Plans and pawn structure

The pin forces White to choose between keeping the knight on c3 and giving up the structure. After ...Bxc3 bxc3, White has the bishop pair, a half-open b-file and central pawns, while Black is a pawn up with a solid kingside. Black's main break is ...d5, often after ...Nge7. White plays Bf4, Bd3 and e5 ideas, and later uses the bishops against Black's dark squares.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position −0.31: a slight edge for Black. Its three top choices for White:

  1. −0.31 7.O-O Nge7 8.Bf4 Bxc3 9.bxc3 d5
  2. −0.43 7.Bf4 Nf6 8.e5 Ne4 9.O-O Bxc3
  3. −0.52 7.Qe2 Nge7 8.O-O Ng6 9.Rd1 O-O

Pawns, from White's side.

How it scores on lichess

575 rated lichess games reached this position; White scored 48.5%.

1200–159950.0%
1600–199946.6%
2000 and up50.5%

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

How to play against it

As White, castle first and do not fear the doubled pawns after ...Bxc3. Keep the bishops active and put a rook on the b-file or d-file. Avoid a passive Bd2 to defend c3, which wastes the c1 bishop. Your compensation is open files, not structure.

Questions

What are the moves of the Sicilian Defense: Smith-Morra Gambit Accepted, Pin Defense?

The Sicilian Defense: Smith-Morra Gambit Accepted, Pin Defense starts 1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 Bb4. Its ECO code is B21.

Is the Sicilian Defense: Smith-Morra Gambit Accepted, Pin Defense good for Black?

Stockfish 17.1 rates the position −0.31 at depth 20, which is a slight edge for Black. In 575 lichess games from our sample, White scored 48.5%. A sensible choice for Black players who like simplifying, while White needs to value the bishop pair over pawn structure.

What is the main idea of the Sicilian Defense: Smith-Morra Gambit Accepted, Pin Defense?

Black pins and often takes the c3 knight, removing one of White's best attacking pieces. White accepts doubled pawns in return for two bishops and open files.

What should White play next?

The engine's first choice is O-O, with Bf4 and Qe2 close behind. 7.O-O lets White meet ...Bxc3 with bxc3 and quick rook play, accepting the doubled pawns for activity.

Updated October 2026. Sources and method.