Two Knights: Morphy, Steiner Variation

Two Knights Defense: Morphy (also called Morphy Attack)

Definition

The Morphy line of the Two Knights Defense arises after the moves 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5. By leaping the g5-knight into Black’s camp, White immediately attacks the sensitive f7–square and threatens the fork 5. Nxf7. It is named for the 19-century American prodigy Paul Morphy, whose open, tactical style popularised the idea of an early knight incursion against f7.

Main Move-Order

• 4…d5 – the principled counter in the centre.
• 5. exd5 Nxd5 (or 5…Na5 in the Steiner line) is the classical continuation.

Strategic Themes

• Immediate Tactical Pressure. White gambles a tempo to pose serious questions about Black’s king safety. Accurate defence is required from move four.
• Central Tension. After 4…d5 5. exd5, Black must decide between 5…Nxd5 (entering wild complications after 6. d4) or 5…Na5 (Steiner) to regain material calmly.
• Development vs. Material. In many variations White will be a pawn up but behind in development, or vice-versa, leading to dynamic, unbalanced middlegames.

Typical Plans

1. For White
   • Rapid mobilisation with d2-d4, castling, and Qf3 or Qh5.
   • Target f7 and the c7–square (often with Bc4-d5).
   • Exploit pins along the a2–g8 diagonal.
2. For Black
   • Return material if necessary to complete development.
   • Seek counterplay in the centre with …e4 or …f5.
   • Coordinate pieces to neutralise the g5-knight, sometimes by rerouting …Nf6–g4 or …Nd5–f4.

Historical & Theoretical Significance

First analysed by the Italian master Giulio Polerio (late 1500s), the line was revitalised by Paul Morphy, whose stunning victories over lesser-prepared opponents made 4. Ng5 the main test of the Two Knights for over a century. Modern engines still consider it the most critical choice, and it features at every level from junior events to elite super-tournaments.

Illustrative Example

Morphy – Count Isouard & Duke of Brunswick, Paris 1858

Morphy sacrifices first the knight and then the queen to deliver a famous mating attack, a textbook demonstration of the power of 4. Ng5.

Interesting Facts

• The move 4. Ng5 scores above 55 % in modern databases, a remarkable statistic for a century-old idea.
• In blitz and bullet, many players still blunder 4…d5 5. exd5 Nxd5? 6. Nxf7! and lose on the spot.
• AlphaZero’s self-play games revived interest in sacrificial sidelines like 6. d4 exd4 7. O-O, showing they remain sound under computer scrutiny.

Two Knights Defense: Steiner Variation

Definition

The Steiner Variation is a specific defensive choice for Black after the Morphy line: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 Na5. Instead of recapturing the pawn with 5…Nxd5, Black counters by immediately chasing the bishop on c4. The variation is named for the Austrian master Hermann Steiner (not to be confused with the earlier Hungarian Carl Steiner) who championed it in the 1930s.

Key Position

After 5…Na5, the critical line continues 6. Bb5+ c6 7. dxc6 bxc6, reaching the diagram below:
White remains a pawn ahead, but Black has the bishop pair and active piece play.

Strategic Ideas

• Material vs. Initiative. Black concedes a pawn yet gains rapid development and half-open files (a-file, b-file) for counterplay.
• Bishop Pair. With the c8-bishop soon fianchettoed to g7, Black’s long-range potential compensates for the missing pawn.
• King Safety. By forcing the white bishop to b5 and blocking checks with …c6, Black diffuses the immediate f7 pressure that characterises the Morphy Attack.

Theoretical Status

Engines give a small but persistent edge to White (±0.30–0.50), yet the complexity and imbalance make the Steiner Variation an attractive practical weapon, especially in shorter time controls where defending an extra pawn is not straightforward.

Notable Games

• Fischer – Reshevsky, US Championship 1959 (Fischer declined the main pawn grab and still obtained pressure, but Reshevsky’s resilient defense held the draw.)
• Anand – Ivanchuk, Wijk aan Zee 1996 (A modern demonstration of Black’s dynamic resources: Ivanchuk equalised smoothly and eventually outplayed Anand in the endgame.)

Typical Tactical Motifs

1. …h6 and …g5. Black often kicks the g5-knight, exploiting the fact that the c4-bishop is misplaced and queenside pieces are poised for action.
2. Latent Knight Jump to c4. The a5-knight reroutes to c4, eyeing both b2 and d2.
3. Exchange Sacrifices. Black may sacrifice a rook on e8 or a8 to open lines against White’s king, trusting the bishops and pawns to finish the job.

Interesting Facts

• The variation was largely overlooked until Hermann Steiner used it to beat Reuben Fine in the 1934 Western Open, creating a splash in American chess circles.
• Top engines suggest an early 8. Be2! followed by 9. d3 as one of White’s best antidotes, a plan scarcely mentioned in older books.
• Because the a5-knight begins on the rim, club players sometimes joke that the line is “a fork waiting to happen,” yet grandmaster praxis shows the knight often becomes the hero on c4 or b7.