Two Knights Defense, Ulvestad Variation

Two Knights Defense, Ulvestad Variation

Definition

The Ulvestad Variation is an aggressive sideline of the Two Knights Defense that arises after the moves:
1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 d5 5. exd5 b5!?
Black immediately sacrifices a pawn on the queenside to lure the bishop off the a2–g8 diagonal and seize the initiative with rapid piece play and central pressure.

Typical Move Order

After 5…b5 White has two principal choices:

• 6. Bf1 Nd4 (“main line” Ulvestad) aiming …Nxd5 and …Qxg5.
• 6. Bxb5+ c6 7. dxc6 Qg5! transposing to the Fritz Variation but with the Black rook already activated on a8.

Strategic Themes

• Rapid Development: Black’s pieces flood the board (…Nd4, …c6, …Bg4) before White can consolidate.
• King Safety: White’s king often remains in the center because castling kingside walks into …Qxg5 ideas, while queenside castling is slow.
• Central Tension: Black looks to occupy d5 and e4 squares, frequently playing …c6, …cxd5 or …e4.
• Material Imbalance: Black is usually a pawn down but counts on activity and tactical threats to compensate.

White’s Best Resistance

Modern theory recommends 6. Bf1 Nd4 7. c3 Nxd5 8. Ne4 Be7 9. cxd4 exd4 with complicated play where accurate defense can leave White with an extra pawn and chances to neutralize the attack. Engines now suggest that precise moves allow White to edge toward an advantage, but the path is narrow and tactically demanding.

Historical Background

The line is named after Aksel B. Ulvestad (1907–1985), an American master and analyst who championed and published analysis of 5…b5 in the 1930s and 1940s. Although never mainstream at elite level, the Ulvestad Variation has appeared in correspondence games and over-the-board encounters by tactically inclined masters looking to surprise their opponents.

Illustrative Mini-Game

The following short game shows typical Ulvestad motifs.

Key Tactical Motifs

• …Qxg5 resource: After 6. Bxb5+ c6 7. dxc6, Black’s queen swings to g5 with tempo, eyeing g2 and the a5–e1 diagonal.
• Bishop skewer on b4: In many lines Black develops the light-squared bishop with …Bb4+, forcing c3 and weakening d3.
• Forks on c2 & e3: A knight on d4 frequently attacks c2 and f3/e2, creating messy double attacks.

Notable Modern Appearances

• D. Dubov – H. Grischuk, Russian Ch. Superfinal 2018: Grischuk unveiled 5…b5 in rapid chess, holding the balance after a wild middlegame.
• N. Miezis – L. Shabalov, Chicago Open 2003: Shabalov’s practical experience with the Ulvestad yielded a 22-move miniature.

Interesting Facts

• Aksel Ulvestad was also a talented violinist; he reportedly composed opening analyses in the margins of sheet-music scores.
• The Ulvestad often transposes to the Fritz Variation if Black later plays …Na5, blurring theoretical boundaries.
• Early engines disliked 5…b5, but modern neural-net engines consider it only slightly worse with best play—making it a viable surprise weapon.

When to Use the Ulvestad

• You enjoy sharp, tactical battles and don’t mind sacrificing material.
• You need a surprise weapon against well-prepared 1. e4 players expecting the main Two Knights lines or the solid Petroff.
• You are willing to study concrete forcing variations—one slip can leave Black simply a pawn down with no compensation.

Practical Tips

1. Memorize the forcing sequence 6. Bf1 Nd4 7. c3 Nxd5 8. Ne4 Be7; both sides must know the details.
2. After 6. Bxb5+ c6, do not fear 7. dxc6; the queen sortie …Qg5! is Black’s key equalizing mechanism.
3. If White castles early, look for sacrifices on f2 and tactical shots along the a7–g1 or h4–d8 diagonals.