Four Knights: Spanish Defence & 5.Nxe5

Four Knights (Four Knights Game)

Definition

The Four Knights Game is an open chess opening that begins with the symmetrical development of all four knights: 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6. Because both sides have brought out their king-side and queen-side knights early, the position is noted for its balance, flexibility, and rich variety of transpositions.

Typical Move Orders

• Classical Main Line: 4. Bb5 (Spanish Four Knights) 4…Bb4 5. O-O
• Scotch Four Knights: 4. d4 exd4 5. Nxd4
• Italian Four Knights: 4. Bc4
• Symmetrical (Gunsberg) Line: 4. g3 d5

Strategic Themes

• Centrally balanced pawn structure. Both sides contest d4 and d5, often delaying pawn breaks until development is completed.
• Piece play over pawn storms. Early minor-piece exchanges or manoeuvres (e.g., Nd5, Nb5, Bg5) give the game a positional rather than tactical character—though sharp options exist.
• Transpositional possibilities. The opening can steer into the Ruy Lopez, Scotch Game, Giuoco Piano, or Petroff-style structures depending on fourth-move choices.

Historical Significance

Popular in the Romantic Era of the 19ᵗʰ century, the Four Knights was considered “sound but tame.” It regained theoretical interest when José Raúl Capablanca used it as a drawing weapon in the 1920s. Modern engines confirm its solidity, leading to sporadic revival in elite play—e.g., Carlsen–Aronian, Wijk aan Zee 2012.

Illustrative Example

After 10…Nxe4, Black equalises, showcasing the solid yet unambitious reputation of the opening.

Interesting Facts

• The first recorded game is La Bourdonnais – McDonnell, 1834, though it did not bear the modern name.
• Because every minor piece stands on its most natural square, beginners often meet the Four Knights in casual play without realising they are following book moves.
• In some databases the ECO code “C48–C49” is shared with the Spanish Four Knights (see next section).

Spanish, Classical Defence (Ruy Lopez – Classical Defence)

Definition

The Classical Defence is a branch of the Ruy Lopez that arises after 1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5.
Black counters the Spanish bishop directly by placing his own bishop on the active c5-square, challenging White’s central ambitions rather than the more popular 3…a6 (Morphy Defence).

Main Variations

• 4. c3 Nf6 5. d4 exd4 6. cxd4 Bb4+ – the Cordel Gambit-like positions.
• 4. O-O Nf6 5. Nxe5 – the Classical, Alapin variation (a double attack on f7 and c6).
• 4. Bxc6 dxc6 5. d3 – exchanging on c6 to damage Black’s pawn structure.

Strategic Ideas

1. Immediate piece pressure. The bishop on c5 eyes f2 and can support …d5 breaks.
2. Dynamic imbalance. Black concedes the strong central pawn structure typical of modern Ruy-Lopez set-ups in exchange for piece activity and tactical chances.
3. King-side safety. Because the c5-bishop vacates e7, Black often castles late or aims for queenside castling after …d6 and …Be6.

Historical Context

The line was championed by 19ᵗʰ-century masters Louis Paulsen and Johannes Zukertort. Although it fell out of favour in the hyper-modern era, it staged comebacks—most notably in Karpov – Kortchnoi, World Championship 1978, where Kortchnoi used the defence to generate complex middlegame fights.

Model Game

Short – Timman, Amsterdam 1991


Short’s brilliant tactical finish illustrates how razor-sharp the Classical Defence can become.

Interesting Facts

• ECO codes C64–C65 cover this line; databases sometimes label it "Ruy Lopez, Spanish Game, Classical Defence."
• Modern computers assess the starting position as roughly equal (≈0.20), signalling practical viability for club and tournament play.
• Because both bishops are outside the pawn chain, a rare double bishop trade can occur as early as move 6.

5.Nxe5 (The Knight Sacrifice on e5)

Definition

The notation 5.Nxe5 refers to White’s fifth-move knight capture of a pawn on e5 in several sharp openings. The most famous context is the Two Knights Defence: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. Nxe5.
Here White momentarily sacrifices material to attack f7, laying the groundwork for the Fried Liver Attack.

Why It Works

1. Overloading f7. By removing the e5-pawn, the queen and bishop coordinate on f7, threatening a fork on c6 or devastating checks.
2. Tempo gain. If Black replies 5…Nxe5, the knight on g5 jumps to f7 with double attack, regaining material with interest.
3. Pinned defenders. After 5.Nxe5, the d6-square is weakened, the c6-knight is often pinned, and Black’s king remains in the centre.

Key Continuations (Two Knights)

• 5…Nxe5 6. d4 – Lolli Attack ideas after 6…Nxc4 7. dxe5.
• 5…dxc4 – Traxler Counter-gambit (if Black had played 4…Bc5), illustrating transpositional overlap.
• 5…Na5 6. Bb5+ – Polerio Defence, leading to complex tactical battles.

Other Openings Featuring 5.Nxe5

• Ruy Lopez, Classical Defence: 1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. O-O Nf6 5. Nxe5. White exploits the pin on the f6-knight.
• Scotch Gambit, Dubois Variation: 1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Bc4 Nf6 5. Nxe5.

Historical Anecdote

The earliest known example of 5.Nxe5 in the Two Knights is the 1619 manuscript of Giulio Cesare Polerio. He described the sacrifice as “una finta per la gola del Re” (a feint at the king’s throat).

Model Miniature

Adams – Torre, New Orleans 1920 (Fried Liver)

Engine Evaluation and Modern Verdict

Stockfish 16 assesses the Two Knights main line after 5.Nxe5 Nxe5 6.d4 at roughly +0.80 for White—confirming genuine compensation but also offering Black resources. Consequently, 5.Nxe5 remains a favourite at junior and amateur levels, while professionals tend to prefer 4.d3 or 4.Ng5 d5 5.Bb5 to limit forcing play.

Interesting Facts

• The move has its own ECO reference: C57 (Two Knights, Fried Liver).
• In blitz, many players still fall victim to the “fork on f7 and c6,” making 5.Nxe5 one of the most successful surprise weapons online.
• Contrary to popular belief, the sacrifice is not objectively winning; precise defence with …Na5 and …b5 often neutralises White’s initiative.