Chess Openings Lab
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Benoni Defense: Semi-Benoni

The Semi-Benoni locks the center with 2...e5 and 3...d6, giving White pawns on d5 and e4 against c5, d6 and e5. Because White's c-pawn is still on c2, the c4 square is free for a White knight, while Black hopes for ...f5 to free the game.

Moves
1.d4 c5 2.d5 e5 3.e4 d6
ECO
A44
Engine
+1.37 · a clear edge for White (Stockfish 17.1, depth 20)
Played
360 games in our lichess sample
White scores
54.0%

Key ideas for both sides

White

  • Route a knight to c4 with Nd2 or Na3; with the c-pawn home, c4 is a perfect square hitting d6 and e5.
  • a4 stops ...b5 and makes a knight on c4 impossible to dislodge with pawns.
  • Bb5+ trades off Black's good light-squared bishop, as in the top engine line, leaving the e7 bishop hemmed in by d6 and e5.

Black

  • Develop with ...Be7, ...Nf6 and short castling, then aim for ...f5 once the f6 knight has moved.
  • ...Na6 heads for c7, where the knight covers b5 and supports a later ...b5 push.
  • Because White's a4 comes quickly, ...b5 is hard to arrange, so ...g6 and ...f5 is usually the main lever.

Plans and pawn structure

With the center locked, each side plays on the wing its pawns point to. White's pawns point to the queenside, so White plays a4, puts a knight on c4 and sometimes prepares b4. Black's pawns point to the kingside, so after castling Black prepares ...f5 with ...g6 and a knight move. The trade of light-squared bishops after Bb5+ helps White, since Black's remaining bishop on e7 is stuck behind its pawns. A knight on c4 against that bishop is White's ideal.

Where the engine's main line heads: Locked center: d5–e4 against d6–e5. A locked center: White's d5 and e4 against Black's d6 and e5. The game moves to the wings, where each side attacks where its pawns point.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +1.37: a clear edge for White. Its three top choices for White:

  1. +1.37 4.Nd2 Be7 5.a4 Na6 6.Bb5+ Bd7
  2. +1.31 4.Ne2 Nf6 5.Nd2 Be7 6.Nc3 O-O
  3. +1.27 4.a4 Be7 5.Nc3 Nf6 6.Nf3 O-O

Pawns, from White's side.

How it scores on lichess

360 rated lichess games reached this position; White scored 54.0%.

1200–159958.3%
1600–199950.5%
2000 and up54.6%

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

How to play against it

As White, do not rush the knights to ordinary squares. The engine prefers Nd2 and Ne2 so that the knights can reach c4 and later c3 or g3, with the f-pawn free to advance. Play a4 before Black gets ...b5, and look for Bb5+ to swap the light-squared bishops.

Questions

What are the moves of the Benoni Defense: Semi-Benoni?

The Benoni Defense: Semi-Benoni starts 1.d4 c5 2.d5 e5 3.e4 d6. Its ECO code is A44.

Is the Benoni Defense: Semi-Benoni good for Black?

Stockfish 17.1 rates the position +1.37 at depth 20, which is a clear edge for White. In 360 lichess games from our sample, White scored 54.0%. Solid but passive for Black; it suits players who enjoy slow maneuvering, while White gets an easy plan built around the c4 square.

What is the main idea of the Benoni Defense: Semi-Benoni?

The center is completely blocked, so the game is about squares. White wants a knight on c4 and the light-squared bishops traded, while Black wants ...f5 to open the kingside.

What should White play next?

The engine's first choice is Nd2, with Ne2 and a4 close behind. 4.Nd2 heads for c4 and keeps the c-pawn free, so the knight can settle on the ideal square.

Updated October 2026. Sources and method.