Italian Game Knight Attack: Polerio Bishop Check Bogoljubov
Italian Game – Knight Attack
Definition
The Knight Attack is the sharpest branch of the Italian Game. After the moves 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 (the Two Knights Defence), White plays 4. Ng5, jumping the king’s knight to g5 and creating an immediate double attack on Black’s vulnerable f7-square with the knight and the bishop on c4.
Typical Move-order
The diagram that appears after 4.Ng5 is the quintessential “fork-on-f7”
position every club player meets early in their career.
Strategic Ideas
- For White: Exploit the tactical weakness of f7 before Black can castle; be ready to sacrifice material for an attack or transition into an extra pawn end-game if Black blunders.
- For Black: Decide between
- 4…d5 – the classical way to hit back in the centre, or
- 4…Bc5 – the ultra-sharp Traxler (Wilkes–Barre) Counter-attack.
Historical Significance
The idea of leaping to g5 dates back to the 16-century Italian theoretician Giulio Cesare Polerio, long before algebraic notation existed. The line became fashionable again during the romantic era; Paul Morphy won several brilliant miniatures with it. Modern greats such as Mikhail Tal and Garry Kasparov have also used the Knight Attack when they wanted a direct fight from move four.
Illustrative Example
Kasparov employed a modern treatment against Deep Blue in 1997, steering for quieter waters with 5.d3 instead of the pawn grab, but the classical tactical slug-fest is shown in the miniature below:
Interesting Facts
- The Knight Attack is coded C57–C59 in ECO.
- Nearly 40 % of on-line blitz games in the Italian reach 4.Ng5.
- Engines evaluate the main line as roughly equal, but the practical winning chances for the better-prepared side are enormous.
Polerio Defense – Bishop Check Variation
Definition
The Polerio Defense arises after the critical pawn break 4…d5. When White captures the pawn and Black’s knight sidelines to a5, we reach the Bishop Check sub-variation: 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.Bb5+. The interposed check is designed to gain a tempo before attending to the threat against c4 and the loose knight on g5.
Key Position
Notice how both of Black’s knights sit on the edge while the f7-pawn is
still under fire.
Strategic Themes
- White hopes to keep the initiative by forcing Black to block with the bishop (6…Bd7) or the knight (6…c6). In many lines White later castles queenside and attacks the black king in the centre.
- Black relies on the pawn thrust …c6 to drive the checking bishop away, then aims for …cxd5 reclaiming the pawn and central space. Accurate defence converts long-term structural assets (the bishop pair and a central pawn majority).
Historical & Theoretical Notes
Polerio’s manuscripts (around 1590) already analysed 6.Bb5+. The line lay dormant until the early 20-th century, when players such as Rudolf Spielmann and Frank Marshall revived it. Today it enjoys a sound reputation; top engines show Black can equalise, but practical results still tilt towards the attacker in rapid time-controls.
Sample Continuation
Anecdote
Legend says that Polerio’s original analysis of this exact bishop check was found on loose pages used to wrap a fish at a Naples market in the 1880s – a romantic (if fishy) illustration of how old ideas can be rediscovered.
Bogoljubov Variation (within the Polerio Bishop Check)
Definition
Named after the combative grandmaster Efim Bogoljubov, this variation enters after the moves 6…c6 7.dxc6 bxc6 8.Qf3 Rb8!. Black unpins the b-pawn, guards b7 and prepares …h6 followed by normal development, showing that material imbalance (two pawns down) can be traded for piece activity and king safety.
Move-order & Critical Position
The rook lift to b8 is the signature Bogoljubov move.
Black threatens …h6 and …Be7 while eyeing the half-open b-file.
Main Plans
- Black:
- Clamp down on the b-file with …Rb8 and …Bb7;
- Kick the g5-knight with …h6, sometimes allowing …hxg5;
- Castle queenside if needed, leaving the rook active.
- White:
- Exploit the extra pawns by consolidating with d3 & Nc3;
- Target Black’s king before the defence is completed, often via Bc4-xf7+ sacrifices;
- Avoid needless exchanges that would ease Black’s cramped position.
Historical Example
Capablanca – Bogoljubov, Moscow 1925 featured the new idea 8…Rb8. Although Capablanca ultimately won, Bogoljubov’s resource inspired future generations and the line still carries his name.
Interesting Facts
- The rook swing …Rb8 violates the classical rule “develop minor pieces before major pieces,” yet modern engines confirm its soundness.
- In correspondence games the Bogoljubov Variation scores above 50 % for Black, despite the material deficit.
- Because 8.Qf3 is practically forced for White, the entire variation is easy to reach but difficult to navigate without deep preparation.