Chess Openings Lab
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Sicilian Defense: Kronberger Variation

The Kronberger Variation is 2.Na3, a rare knight move to the rim against the Sicilian. White hopes to route the knight to c4 or b5 later, while Black can simply take the center with ...Nc6, ...d5 or ...e6 and develop freely.

Moves
1.e4 c5 2.Na3
ECO
B20
Engine
−0.05 · level (Stockfish 17.1, depth 20)
Played
93 games in our lichess sample
White scores
34.9%

Key ideas for both sides

White

  • Use the a3 knight on c4 or b5, where it can hit d6 or support a later d4 push.
  • Against ...Nc6, the engine plays Bb5 to pin and then Qf3 after the center opens, trading queens toward an even ending.
  • A g3 and Bg2 setup with Ne2 and c3 gives the a3 knight a quieter role behind the pawns.
  • Do not expect an advantage. Treat 2.Na3 as a way to reach unfamiliar, offbeat positions.

Black

  • 2...Nc6 develops and allows ...d5, since after Bb5 and exd5 Black's queen recaptures with tempo ideas.
  • 2...d6 with ...g6 and ...Bg7 builds a solid kingside against White's g3 and Bg2 setup.
  • 2...e6 followed by ...d5 claims the center at once, and the knight on a3 does nothing to stop it.
  • Keep developing normally. The rim knight is slow, so time is on Black's side early.

Plans and pawn structure

White's knight on a3 is the whole story. It needs time to reach c4 or b5, so Black can grab central space with ...d5 or a quick ...e6 and ...d5. If White answers with e5, the a3 knight later supports c3 and d4. If Black goes ...Nc6 and ...d5, the queens may come off early after Bb5, exd5 and Qf3, leading to an even, simplified game. In fianchetto lines, both sides castle short and play slowly, with White eyeing b5 and Black pushing on the queenside.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position −0.05: level. Its three top choices for Black:

  1. −0.05 2...Nc6 3.Bb5 d5 4.exd5 Qxd5 5.Qf3
  2. −0.05 2...d6 3.g3 Nc6 4.Bg2 g6 5.Ne2
  3. −0.05 2...e6 3.Nf3 Nc6 4.c3 d5 5.e5

Pawns, from White's side.

How it scores on lichess

93 rated lichess games reached this position; White scored 34.9%.

2000 and up38.7%

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

Where it goes next

  • Kronberger Variation, Nemeth Gambit2...Nc6 · rare

How to play against it

Black should play 2...Nc6, 2...d6 or 2...e6 and aim for ...d5. Do not try to punish the knight with wild pawn pushes; simple central play is enough. If White plays Bb5 early, be ready to trade queens rather than chase complications.

Questions

What are the moves of the Sicilian Defense: Kronberger Variation?

The Sicilian Defense: Kronberger Variation starts 1.e4 c5 2.Na3. Its ECO code is B20.

Is the Sicilian Defense: Kronberger Variation good for White?

Stockfish 17.1 rates the position −0.05 at depth 20, which is level. A surprise weapon for White players who want unusual positions, but it gives Black an easy game with simple development.

What is the main idea of the Sicilian Defense: Kronberger Variation?

White develops the queenside knight to a3 to route it to c4 or b5 while keeping the c-pawn free. Black answers with fast central play, usually ...Nc6 and ...d5, and has no problems.

What should Black play next?

The engine's first choice is Nc6, with d6 and e6 close behind. 2...Nc6 develops a knight and prepares ...d5, using the time White spent on a3.

Updated October 2026. Sources and method.