ECO B90Repertoire for Black

Sicilian Najdorf - 1... c5

The crown jewel of the Sicilian. With 5...a6 Black controls b5 and prepares ...e5, aiming for dynamic counterplay on both wings.

Sicilian Najdorf - 1... c5

Move1 / 20

1. e4

White’s first move.

Overview

The Najdorf Sicilian (ECO B90–B99) is the most analysed opening in chess history — and arguably the most prestigious. After 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3, the little move 5...a6 of the Polish-Argentine grandmaster Miguel Najdorf conceals a complete programme: deny b5 to the white pieces (no more Nb5 jumps towards d6), prepare ...e5 without fearing the Bb5+ pin, and begin the ...b5 expansion that will give Black a lifetime of queenside counterplay.

Its history is that of the attacking champions: Bobby Fischer made it his near-exclusive weapon against 1.e4, Garry Kasparov carried it to theoretical summits for twenty years, and it remains today the favourite battlefield of engines and world championship matches. To play the Najdorf is to accept entering the deepest theory there is — the Poisoned Pawn Variation (6.Bg5 e6 7.f4 Qb6) has been analysed beyond move thirty.

The key idea is total asymmetry: Black trades the c-pawn for the central d-pawn and plays a different game from the opponent — pressure on the half-open c-file, ...e5 or ...e6 pushes depending on White’s system, a king that castles late or not at all. White picks a war at move six: 6.Bg5 (the sharpest), 6.Be3 (the English Attack), 6.Be2 (the classical), 6.Bc4 (Fischer-Sozin).

It is an expert player’s opening: a born counter-attacker, a solid calculator, a lover of imbalance. Below 1800 ELO it can be played on general plans; above, it demands genuine theoretical work — and repays it a hundredfold.

The main line, move by move

Every move is explained: play through them in order to understand the opening’s logic.

1. e4White’s first move.
1… c5The Sicilian: an asymmetrical fight for the centre.
2. Nf3Development.
2… d6Supports ...e5 and frees the c8 bishop.
3. d4Opens the centre.
3… cxd4Central exchange.
4. Nxd4Recapture with the knight.
4… Nf6Attacks e4 and develops.
5. Nc3Defends e4 and develops.
5… a6The Najdorf move: prepares ...e5 and ...b5.
6. Be3English Attack: prepares f3, Qd2 and queenside castling.
6… e5Gains space and chases the d4 knight.
7. Nb3Knight retreat.
7… Be6Develops and watches over d5.
8. f3Supports e4 and prepares g4.
8… Be7Develops and prepares to castle.
9. Qd2Connects towards queenside castling.
9… O-OBlack castles.
10. O-O-OQueenside castling: opposite-side castling.
10… Nbd7Develops and prepares ...b5.

Plans for both sides

Black’s plan

Black’s plan begins with a profession of faith: 5...a6 is no waiting move, it is the key to the whole setup. It prepares ...e5 (fearing neither Nb5 nor Bb5+), winning the centre at the price of the d5 hole and the backward d6-pawn, or ...e6 in the systems where flexibility comes first. The vital counterplay comes from the queenside: ...b5, ...Bb7, ...Nbd7-b6 or -c5, and the half-open c-file where the c8-rook and the queen on c7 lean on c2 and c3. Against the opposite-castling pawn storms (English Attack, 6.Bg5), tempo is everything: Black does not defend, Black counter-attacks faster — ...b4 kicks the c3-knight that protects e4, and the whole white edifice comes apart. The thematic exchange sacrifice ...Rxc3! is part of the toolkit: destroying c3 often means destroying the entire white king’s cover. Two non-negotiable disciplines: cover the d5-square at all times (a white knight settling there for free equals a blunder), and prepare the ...d5 break as a long-term project — when it works, the Najdorf wins the centre AND the initiative in a single move. It is this combination of concrete solidity and latent violence that makes it the queen of Sicilians.

White’s plan

Against the Najdorf, White first chooses a philosophy. The English Attack (6.Be3, f3, Qd2, long castling) is the most systematic plan: lock e4, launch g4-g5 and h4 against the black king, and make the d5-square the strategic outlet for every piece. The race is then against the clock: every tempo wasted on the kingside is paid for on the queenside where Black pushes ...b5-b4. With 6.Bg5 and 7.f4 you enter total theoretical war: the f6-knight pinned, the e5 threat, Qf3/Qd2 batteries with long castling. This is the road for prepared players — improvising there is playing roulette. Conversely, 6.Be2 (the classical) and 6.g3 bet on strategy: contain ...e5 by exploiting the d5 hole, settle on the d-file, and turn the backward d6-pawn into a long-term target. Two constants run through every system: the d5-square — every exchange that brings pieces closer to it serves White — and watching for the ...d5 break, the liberation Black is permanently preparing. The best practical advice remains that of the specialists: pick ONE system against the Najdorf and know it deeply, rather than skimming four.

Main variations

Najdorf Variation
ECO B96
White pins the f6 knight and aims for a direct attack with f4 and queenside castling.
Najdorf Variation, Opocensky Variation
ECO B92
Quiet development of the bishop to e2 followed by short castling: a positional approach.
Najdorf Variation
ECO B90
Frequent line: 6.Bg5, the 10.Bd3 reply (~26% at peer level). Engine-verified continuation.
Najdorf Variation, Opocensky Variation
ECO B90
Frequent line: 6.Be2, the 10.f3 reply (~17% at peer level). Engine-verified continuation.
Sicilian Najdorf — 10.g4
ECO B90
Frequent line: the 10.g4 reply (~14% at peer level). Engine-verified continuation.
Najdorf Variation, Lipnitsky Attack
ECO B90
Frequent line: the 6.Bc4 reply (~14% at peer level). Engine-verified continuation.
Najdorf Variation, Yates Variation
ECO B90
Frequent line: the 6.Bd3 reply (~8% at peer level). Engine-verified continuation.
Sicilian Defense: Najdorf Variation, English Attack (6.f3)
ECO B90
Frequent line: the 6.f3 reply (~8% at peer level). Engine-verified continuation.
Sicilian Defense: Najdorf Variation, English Attack (7.Nf3)
ECO B90
Frequent line: the 7.Nf3 reply (~19% at peer level). Engine-verified continuation.
Najdorf Variation, Opocensky Variation
ECO B90
Frequent line: 6.Be2, the 8.Bg5 reply (~8% at peer level). Engine-verified continuation.
Sicilian Najdorf — 8.Qd2
ECO B90
Frequent line: the 8.Qd2 reply (~16% at peer level). Engine-verified continuation.
Sicilian Najdorf — 8.Be2
ECO B90
Frequent line: the 8.Be2 reply (~18% at peer level). Engine-verified continuation.
Najdorf Variation, Opocensky Variation
ECO B90
Frequent line: 6.Be2, the 9.f4 reply (~25% at peer level). Engine-verified continuation.

Typical pawn structures

The ...e5 structure: d5 hole versus backward d6-pawn

The Najdorf’s central bargain in one picture: ...e5 has gained space and pushed the d4-knight away, at the price of the d5 hole and a backward d6-pawn on a half-open file. White plays against those two targets: install a knight on d5 (every minor-piece exchange brings that dream closer), lean on d6 down the d-file — here with the English Attack’s opposite castling, g4-g5 comes as a bonus. Black proves the opposite: ...Be6 and ...Nbd7 cover d5, the ...d5 break remains the supreme liberation, and ...b5-b4 launches the counter-offensive that turns d6 into a footnote in the storm.

Opposite castling: the g4 assault against the ...b5 wave

The war structure of 6.Bg5: a small black centre e6-d6, White castled long, and two pawn avalanches launched at each other. White pushes g4-g5 to evict the f6-knight and open lines towards h7-g7; f4-f5 strikes e6 at the critical moment. Black answers ...b5-b4: kicking the c3-knight undresses e4 and the c1-king’s diagonal — the ...Rxc3 sacrifice hovers permanently. In this race the rule is brutal: whoever plays one defensive move too many has lost. Count tempi, not pawns.

Common mistakes

Playing a6 without knowing why. Many players copy the Najdorf moves as a formula and are then left without a plan. a6 only makes sense if it is followed by genuine queenside counterplay: without b5, it is a wasted move and White gets the initiative for free.

Neglecting the d5 square. After e7-e5 the d6 pawn becomes backward and d5 is permanently weakened. Casually trading the e6 bishop or the f6 knight simply hands that square to White, who will park a piece there for good. Every exchange should be judged against this hole.

Defending passively in opposite-side castling. The natural reflex against g4-g5 is to retreat and consolidate, but that is exactly how you lose the race. In these positions a tempo spent defending is often a tempo donated to the opponent’s attack: counterplay must come first.

Frequently asked questions

Why does Black play a6 as early as move five in the Najdorf?

a6 denies White’s pieces the b5 square, in particular the knight jump Nb5 hitting the d6 weakness. It also prepares the b7-b5 expansion, which is the engine of Black’s queenside counterplay.

Is the Najdorf too theoretical for a club player?

It is heavily theoretical at the top level, but at 800-1400 ELO games leave theory very early. Understanding the structures, the d5 square, and the opposite-castling race pays far more than memorising long lines.

Why play e5 if it weakens d5 and d6?

e5 gains time by attacking the d4 knight and gives Black a share of the centre plus active squares for the pieces. It is a conscious trade-off: activity in exchange for a permanent structural weakness.

What should I do when White pushes g4 and h4 at my castled king?

Do not panic and do not pull every piece back to defend: the right answer is to speed up b5-b4 and open lines toward White’s king. Count the tempi of both attacks instead of reacting move by move.

Results by rating level

WhiteDrawsBlack

Most-played lines (1600–1799 level)

Central capture cxd4cxd495%
48% wins (White)
Anti-Qxd4 …Nf6Nf61%
50% wins (White)
Knight to c6Nc61%
57% wins (White)
Pin …Bg4Bg41%
56% wins (White)
Queenside fianchetto b6b60%
59% wins (White)
Central thrust …e6e60%
55% wins (White)

The percentage shows the move’s popularity (share of games that play it). White’s score stays near 50% because all of these lines are sound — popularity is what sets them apart.

Reference games

Step through each game at your own pace with the arrows — it opens at the end of the opening.

Carlsen, M.. (2862) — Vachier Lagrave, M.. (2784)Draw · 2021

Undefeated World Champion Magnus Carlsen goes head-to-head with Maxime Vachier-Lagrave, the French grandmaster known as 'MVL' and widely regarded as one of the world’s foremost experts on the Sicilian Najdorf. MVL has long held the record as the highest-rated French player in history. When Carlsen opts for the Najdorf against its greatest living specialist, you know the battle will be exceptionally intense.

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Ding, Liren (2791) — Carlsen, Magnus (2863)White wins (resignation, time or agreement) · 2020

Ding Liren, the Chinese grandmaster who would go on to become World Champion in 2023, faces Magnus Carlsen in a Sicilian Najdorf. Ding is renowned for his encyclopedic opening preparation and exceptional defensive resilience. Against him, Carlsen deploys the Najdorf — an opening historically associated with the game’s greatest attackers — to probe the limits of China’s elite preparation.

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Nepomniachtchi, Ian (2784) — Carlsen, Magnus (2863)Black wins (resignation, time or agreement) · 2020

Ian Nepomniachtchi, one of the most gifted Russian grandmasters of his generation, faces a Magnus Carlsen who boldly takes up the Sicilian Najdorf with the Black pieces — a sharp choice that reflects the Norwegian’s supreme confidence in his preparation. Carlsen has spoken on multiple occasions of his admiration for Fischer, the great apostle of the Najdorf, making this opening choice all the more symbolic.

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Carlsen, M. (2872) — Aronian, L. (2775)White wins (resignation, time or agreement) · 2019

Reigning World Champion Magnus Carlsen meets Levon Aronian again, this time in a Sicilian Najdorf — one of the most complex and combinatively rich openings in all of chess. Aronian, the flamboyant Armenian grandmaster who never shies away from imbalance, is a dangerous opponent in exactly these kinds of sharp positions. A clash between two world-class players in the Najdorf all but guarantees a firework display of tactics and strategic subtlety.

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Model games

Real master games in this opening, reviewed at depth 25 — open one to study the eval graph, move classifications and key turning points.