Sicilian: Prins (Moscow), 5...Nc6 6.c4 Qb6

Sicilian: Prins (Moscow), 5...Nc6 6.c4 Qb6

Definition

The Prins (also called the Prins Variation) is a branch of the Moscow System of the Sicilian Defence that arises after the moves 1.e4 c5 2.Nf3 d6 3.Bb5+ Bd7 4.Bxd7+ Qxd7 5.O-O Nc6 6.c4 Qb6. It is named after the Dutch master Dirk Prins, who explored the setup in the mid-20th century. In this line Black immediately develops the knight to c6 instead of the more traditional 5…Nf6, and then counter-attacks the central dark squares by placing the queen on b6 to pressure d4 and b2. White, by playing 6.c4, grabs central space and clamps down on d5.

Typical Move Order & Position

The main sequence is:

1. e4 c5
2. Nf3 d6
3. Bb5+ Bd7
4. Bxd7+ Qxd7
5. O-O Nc6
6. c4 Qb6

The resulting position usually features:

• A flexible Maroczy-style pawn structure for White with pawns on e4 and c4, controlling d5.
• A queen on b6 for Black hitting the b2-pawn and eyeing the d4 square, often provoking White to play 7.Nc3 or 7.d3.
• Minor-piece development races—Black often fianchettoes the dark-squared bishop with …g6 and …Bg7, while White chooses between a “hedgehog squeeze” (d3, Nc3, Rb1, a3) and an early central break with d4.

Strategic Ideas

For White:

• Maintain the c4/e4 pawn duo to restrict …d5.
• Decide the timing of d2-d4—too early may allow …cxd4 followed by …Nf6 and …g6 with comfortable play for Black.
• Exploit the queen’s slightly exposed placement on b6 with a timely Nc3-d5 jump or Be3.

For Black:

• Pressure the b-file (…Qb6, …g6, …Bg7, …Nf6, …O-O, …Rfb8) and look for queenside counterplay.
• Prepare …d5 in one blow (often after …Nf6 and a later …Rfe8) to free the position.
• Keep an eye on the d6-pawn; sometimes …e6 is played to reinforce it and give the c8-bishop the c6-square.

Historical Significance

Dirk Prins introduced the set-up against the Moscow Variation in the 1950s, but it achieved wider recognition through the games of Garry Kasparov in the early 1980s. Kasparov employed the line successfully against both Karpov and top Soviet grandmasters, popularising the immediate 5…Nc6. Since then, the variation has been a regular guest at elite events, favoured by players who enjoy Hedgehog & Maroczy structures from the Black side without entering the open Sicilian.

Model Games

• Karpov – Kasparov, Moscow blitz 1982
  
• Caruana – Vachier-Lagrave, Wijk aan Zee 2019 (demonstrates a modern treatment with 7.Nc3 Bg7 8.Rb1 Nf6 9.Re1).

Interesting Facts & Anecdotes

• Because 5…Nc6 violates the classical rule of “develop knights before queens,” Black must justify the early queen move to b6—exactly the sort of dynamic imbalance many Sicilian aficionados relish.
• In databases the variation sometimes appears under two names: “Prins” and “Moscow 5…Nc6.” Don’t be confused— they are the same thing; the label depends on whether your source prioritises the third-move check (Moscow) or the knight jump (Prins).
• Engines initially disliked Black’s plan in the early 2000s, rating the space-grab 6.c4 highly for White; modern neural networks now consider the position fully playable for both sides—illustrating how computer opinion can swing with deeper understanding.

Practical Tips

• White players should memorise 7.d4!? as a surprise; after 7…cxd4 8.Nxd4 Nf6 9.Nxc6 Qxc6 10.f3 White keeps a Maroczy bind with a small plus and an unopposed dark-squared bishop.
• Black must watch out for the tactical shot Qxd6!? when the d-pawn becomes loose—especially if the queen leaves b6 or the king is still in the centre.