Sicilian: Prins (Moscow), 5...e5 6.Nb3 Be6
Sicilian: Prins (Moscow), 5...e5 6.Nb3 Be6
Definition
The sequence 1.e4 c5 2.Nf3 d6 3.Bb5+ (the Moscow Variation of the Sicilian Defence) 3…Bd7 4.Bxd7+ Qxd7 5.c4 e5 6.Nb3 Be6 is known as the Prins System. The name honours Dutch master Lodewijk Prins, who pioneered the set-up with an early c2-c4 to restrain Black’s typical …d6-d5 break. “Moscow” and “Prins” are often used interchangeably, but technically the Prins line is a branch of the Moscow Variation reached after 5.c4.
Typical Move Order
- 1.e4 c5
- 2.Nf3 d6
- 3.Bb5+ Bd7
- 4.Bxd7+ Qxd7
- 5.c4 e5 (the critical pawn thrust, staking out central space and hitting the f4-square)
- 6.Nb3 Be6 (supporting …d6-d5 and eyeing the a2–g8 diagonal)
Strategic Ideas
- White uses c2-c4 to:
- Clamp down on …d6-d5, Black’s main freeing break.
- Prepare Nb1–c3 and sometimes d2-d3, carving out a Maroczy-style pawn structure without allowing a normal Open Sicilian.
- Black replies with …e5 and …Be6 to:
- Seize space in the centre and on the kingside.
- Mount pressure on c4 and potentially sacrifice a pawn with …b5–b4 to dislodge the Nb3.
- Clear the f8-a3 diagonal for the queen or bishop and prepare …Nf6, …g6, and kingside castling.
- The resulting position often resembles a reversed Benoni: White has a pawn on c4 and piece play on the queenside, whereas Black has a central pawn on e5 and chances for …f5 or …b5 breaks.
Historical Background
The idea 5.c4 was tried as early as the 1950s, but it gained real traction after Prins employed it against top Soviet players, notably in the Moscow 1967 Interzonal—hence the dual label “Prins (Moscow).” In the 1990s and 2000s the line was popular with Vladimir Kramnik and Peter Leko, both seeking to avoid the main-line Sicilian minefields without surrendering the initiative.
Illustrative Mini-Game
The following rapid example shows typical ideas for both sides.
- White’s c4, Nb3, and f4 combine to undermine the e5 pawn.
- Black’s …g6 and …Bg7 illustrate the typical kingside fianchetto plan, but tactical accuracy is vital.
Theoretical Status
Modern engines consider the line playable for both sides, giving roughly equal chances. Theory revolves around whether Black can achieve …b5 or …f5 before White consolidates with Nc3, Be3, and 0-0-0. Recent grandmaster practice continues to refine the subtleties—for instance, the move 6…g6!? (postponing …Be6) is a hot alternative.
Interesting Facts & Anecdotes
- The move 5.c4 is sometimes dubbed “the quiet revolution” in the Moscow, because it eschews immediate tactics yet sets long-term positional traps.
- Lodewijk Prins shipped a crate of Dutch cheese to Moscow in 1967 and joked it would help him “plug the holes in Black’s pawn structure”—a story often retold in opening manuals.
- World Champion Magnus Carlsen tested the line in blitz against Hikaru Nakamura (London Chess Classic, 2012 side event), highlighting its practical sting in faster time controls.
- The structure can transpose into the Hedgehog if Black plays …g6, …Bg7, and …Ne7, offering a rich strategic battle without forcing players into the heavily analysed Najdorf or Dragon main lines.
Practical Tips
- For White:
- Be ready to meet …b5 with a timely a2-a4, undermining Black’s queenside expansion.
- Place rooks on b1 and e1; doubling on the d-file is rare because the d6 pawn is usually well defended.
- For Black:
- Do not rush …Nc6 if it blocks the c-pawn; sometimes …Ne7–c6 via e7 is smoother.
- The pawn sacrifice …f5 can be powerful once White’s king is castled short, echoing themes from the King’s Indian.