Italian Game Knight Attack Polerio Kieseritzky Variation
Italian Game – Knight Attack, Polerio–Kieseritzky Variation
Definition
The Polerio–Kieseritzky Variation is a sharp branch of the Italian Game’s Knight Attack, reached after the moves:
1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Na5
White’s knight sortie to g5 menaces the f7-pawn, provoking Black’s central counter-thrust 4…d5. After 5.exd5, the move 5…Na5 (instead of the immediate recapture 5…Nxd5) attacks the c4-bishop while keeping the f6-knight trained on d5. The line is named after the 16th-century Italian analyst Giulio Cesare Polerio and the 19th-century French master Lionel Kieseritzky, who both examined and championed the variation in their writings and games.
Typical Move Order
- e4 e5
- Nf3 Nc6
- Bc4 Nf6
- Ng5 d5
- exd5 Na5 (Polerio–Kieseritzky critical position)
- Bb5+ c6
- dxc6 bxc6
- Be2 h6
- Nf3 e4
Black eventually regains the d5-pawn and obtains the bishop pair and a lead in development at the cost of a slightly weakened pawn structure.
Strategic Ideas & Plans
- Black’s Compensation: By delaying the recapture on d5, Black forces the white bishop to an awkward square, seizes space with …c6 and …e4, and preserves the f8-bishop to exert pressure down the a7-g1 diagonal.
- White’s Objectives: Consolidate the extra pawn, complete development quickly (often with 0-0 and d3), and be ready to neutralize Black’s central pawn mass.
- Piece Activity vs. Structure: Black accepts doubled c-pawns but gains active lines, while White enjoys a healthier pawn structure and the first move.
- King Safety: Both sides often castle kingside, yet tactics around the semi-open f-file and the e4-pawn can erupt suddenly.
Key Tactical Motifs
- Fork Tricks on c7 or f7 after Nb5 or Nxf7 in some sidelines when Black misplaces pieces.
- …e4 Break hitting the f3-knight and opening the dark-squared bishop.
- Discovered Checks on the a5-e1 diagonal once the knight moves.
- Exchange Sacrifices such as …Bxf2+ followed by …Qd4+ in certain forcing continuations.
Historical Notes
Giulio Cesare Polerio (c. 1550 – c. 1610) first recorded the 5…Na5 idea in Renaissance manuscripts, analyzing lines that remain topical today. Two centuries later, Lionel Kieseritzky (1806-1853) re-popularized the variation in Paris, adding concrete game examples and refinements. Although overshadowed by Kieseritzky’s more famous gambit in the King’s Gambit Accepted, his work on this Italian 5…Na5 branch left a lasting theoretical footprint.
Illustrative Example
The following training game shows typical themes:
Black’s doubled c-pawns are offset by the bishop pair and an imposing e4-pawn. White seeks to exploit the hole on d5 and the slightly drafty black king.
Notable Games
- Anderssen – Kieseritzky, Paris 1839: An early practical test where Kieseritzky unleashed the 5…Na5 idea, eventually converting his dynamic advantage.
- Kasparov – Bareev, Linares 1994: Kasparov adopted the White side, demonstrating that accurate play can blunt Black’s initiative and convert the extra pawn in the endgame.
Interesting Facts
- In some historical texts the line is dubbed the Polerio Defense, but modern nomenclature places it under the umbrella of the Italian Game.
- Grandmasters such as Vishy Anand and Fabiano Caruana have tested 5…Na5 in rapid or blitz, proving its continued practical appeal.
- The variation often transposes into structures resembling the Open Spanish (5…Na5 in the Ruy Lopez) – a useful crossover for repertoire builders.
When to Use It
Choose the Polerio–Kieseritzky Variation if you enjoy:
- Balanced risk: you gamble pawn structure for piece activity, not material.
- Complex middlegames rich in tactical chances.
- A surprise weapon: many club-level players know 5…Nxd5 well but underestimate 5…Na5.