Sicilian Prins (Moscow), 5...a6
Sicilian: Prins (Moscow), 5...a6
Definition
The Prins (or Moscow) Variation of the Sicilian Defence is reached after the moves 1. e4 c5 2. Nf3 d6 3. Bb5+ Nd7 4. d4 Nf6 5. e5 a6. The check on move 3 is characteristic of the Moscow–Rossolimo complex, and the further advance 5.e5 attacks the knight on f6. Black’s reply 5…a6 (instead of the more forcing 5…Qa5+ or 5…dxe5) is called the Prins move, named after the Dutch grandmaster Lodewijk Prins, who analysed and popularised it in the 1950s. The move simultaneously questions White’s bishop, prepares …b5, and avoids immediate concessions in the centre.
Typical Move-Order & Key Position
Main line: 1.e4 c5 2.Nf3 d6 3.Bb5+ Nd7 4.d4 Nf6 5.e5 a6.
After 6.Bxd7+ (most common) Nxd7 7.exd6 exd6 the characteristic structure
arises – Black has ceded the bishop pair but enjoys a rock-solid pawn
chain and rapid queenside expansion with …b5.
Strategic Themes
- Queenside space: …a6 and …b5 gain room, often forcing White’s bishop to decide between the capture on d7 and retreating.
- Flexible centre: By delaying captures on e5 and d4, Black keeps options open—…cxd4, …dxe5 or even …e6—depending on White’s setup.
- Bishop pair vs. structure: If White exchanges on d7, the resulting position gives White the bishop pair but no immediate targets; Black counts on solidity and piece play.
- Pawn breaks: Typical freeing moves are …cxd4 followed by …e6 or …g6 and …Bg7, putting pressure on the e5-pawn.
Historical Background
Lodewijk Prins introduced 5…a6 into high-level practice against Max Euwe in a 1952 friendly match. The idea soon caught on; Soviet analysts liked the solid but unbalanced structure, and the line appeared regularly in Moscow tournaments—hence the double name “Prins (Moscow).” In the computer era it remains a reliable surprise weapon, used by elite players such as Vladimir Kramnik, Levon Aronian, and Fabiano Caruana.
Illustrative Games
-
Vladimir Kramnik – Veselin Topalov, Linares 1998
Kramnik chose 6.Bxd7+ Nxd7 7.O-O and nursed a small edge, but Topalov equalised with accurate queenside play and the game was drawn after 36 moves. -
Magnus Carlsen – Shakhriyar Mamedyarov, Tata Steel 2011
Carlsen retreated 6.Be2, maintaining the bishop pair. Mamedyarov’s thematic …b5–…Bb7 counterplay secured full equality; Carlsen later out-maneuvered his opponent in a long endgame to win on move 60. -
Anish Giri – Fabiano Caruana, Candidates 2021
A modern example of Black’s resilience: Caruana steered into a dynamic middlegame with opposite-side castling and held the balance with precise calculation.
Typical Plans for Each Side
- White
- Exploit the bishop pair with f4–f5 or c4 aiming at the d6-pawn.
- Queenside castling is common when the bishop stays on b5.
- Use the d5-square as an outpost for knights after c2-c4.
- Black
- …b5–…Bb7 or …g6–…Bg7 to pressure e5.
- Timely …cxd4 and …e6 undermine White’s centre.
- If allowed, …dxe5 followed by …Qc7 and …Be7 leads to a standard Scheveningen-type setup.
Interesting Facts & Anecdotes
- Lodewijk Prins was better known as a FIDE arbiter and chess author, yet this one move—5…a6—ensured his name lives on in opening theory.
- Because it arises from the “safe” Moscow line with 3.Bb5+, the Prins Variation is a favourite of players who want Najdorf-style play without learning the voluminous Najdorf theory.
- In correspondence chess, engines initially believed 6.Be2 to refute 5…a6, but modern neural-network evaluations have swung back, rating the line as perfectly sound for Black—an example of theory’s pendulum.
When to Choose the Prins
Select this line if you are a Sicilian player who:
- Prefers a solid yet flexible structure over the sharper Najdorf or Dragon main lines.
- Is comfortable playing slightly passive positions with long-term queenside activity.
- Wants to sidestep the crushing preparation often accompanying 3.d4 Open Sicilians.
In summary, the Sicilian Prins (Moscow) with 5…a6 is a time-tested, strategically rich system that allows Black to reach unbalanced middlegames with reasonable chances and limited theoretical risk.