Modern Defense, Rat Defense, Accelerated Gurgenidze
Modern Defense
Definition
The Modern Defense is a hyper-modern chess opening characterized by Black’s early fianchetto of the king-side bishop with 1…g6 and 2…Bg7 (or their functional equivalents). Instead of occupying the center with pawns, Black allows White to build a classical pawn center and then attacks it from a distance with pieces and timely pawn breaks such as …c5, …d5, or …e5. ECO codes B06–B09 cover most Modern Defense lines.
Typical Move Orders
- 1. e4 g6 2. d4 Bg7 3. Nc3 d6 — “Standard” Modern
- 1. d4 g6 2. c4 Bg7 3. Nc3 d6 — King’s Indian–flavored Modern
- 1. e4 g6 2. d4 Bg7 3. Nf3 d6 4. Nc3 Nf6 — Pirc transposition
Strategic Ideas
Black’s core strategy is to keep the central structure flexible:
- Influence the light squares (d4, e5) with the fianchettoed bishop.
- Undermine with pawn breaks: …c5 against a white pawn on d4, …e5 against a pawn on d4 and/or e4, or …d5 in “Tiger” setups with …a6 and …b5.
- Retain a robust king position by castling short, while the rook on f8 often joins the central fight via …f5 or …e5.
Historical Significance
Although hyper-modern ideas date back to the 1920s (Nimzowitsch, Réti), the Modern Defense developed an independent identity in the 1950s–60s thanks to Austrian GM Karl Robatsch; the name “Robatsch Defense” still appears in older literature. Later exponents include Bent Larsen, Ljubomir Ljubojević, and more recently GMs like Tiger Hillarp Persson and World Champion Magnus Carlsen, who occasionally employs “Modern-style” setups to avoid heavy theory.
Illustrative Example
In this sample line (Modern Defense, Pseudo-Pirc) Black keeps the structure fluid while eyeing breaks …e5 and …c5.
Interesting Facts
- The line 1.e4 g6 2.d4 Bg7 3.Nc3 d6 4.Be3 a6 is called the “Tiger Modern,” popularized by Swedish GM Tiger Hillarp Persson.
- Because many structures transpose to the Pirc or the King’s Indian, the Modern can be a practical weapon for players who want one repertoire against both 1.e4 and 1.d4.
- Robatsch once defeated Bobby Fischer in a blitz game using the Modern Defense, prompting the quip, “Even Fischer couldn’t tame the g-pawn!”
Rat Defense
Definition
The Rat Defense is an umbrella term for a family of off-beat systems beginning with 1…d6 against 1.d4 (or sometimes 1.e4), in which Black avoids immediate commitment of the king-knight to f6 and looks to strike back with …e5, …c5, or …Nc6 at a moment of their own choosing. ECO codes A41 and A43 usually cover these positions.
Representative Move Orders
- 1.d4 d6 2.c4 e5 — “English Rat,” also called the Lisbon Gambit.
- 1.d4 d6 2.e4 Nf6 3.Nc3 c6 — transposing to a Pirc/Caro hybrid.
- 1.d4 d6 2.c4 Nc6 — Rat Defense, Chigorin-style.
Strategic Themes
- Provocation: Black hopes White will over-extend the center so that breaks like …e5 or …c5 open lines for rapid piece activity.
- Flexibility: By withholding …Nf6 and …g6, Black can shift into Pirc, Old Indian, or even Philidor structures depending on White’s setup.
- Psychological Edge: The rarity and nebulous reputation of the Rat can steer opponents away from prepared mainline theory.
Historical Notes
The name “Rat” is partly humorous—suggesting something lurking in the dark, ready to nibble at White’s center. The term gained traction in online blitz circles during the 2000s, propelled by streamers and creative masters such as IM Cyrus Lakdawala and GM Andrew Martin, who produced instructional videos titled “The Rat.”
Example Game Snippet
Black has sacrificed the right to castle but exerts pressure on e4 and d4, illustrating the unbalanced nature typical of Rat lines.
Interesting Tidbits
- GM Vladimir Kramnik once used a Rat-type setup in online rapid play to defeat a well-prepared engine, praising its “practical venom.”
- The Rat is sometimes jokingly called the “gnawing defense” because it keeps biting at White’s center until it collapses.
- Its move-order trickiness makes it a favorite in bullet chess, where time pressure magnifies the surprise factor.
Accelerated Gurgenidze Variation
Definition
The Accelerated Gurgenidze is a sharp sub-line of the Modern Defense in which Black plays an immediate …d5—skipping the preparatory …c6 that marks the “classical” Gurgenidze System. The critical position arises after
1.e4 g6 2.d4 Bg7 3.Nc3 d5 (ECO code B06, sub-heading “Accelerated Gurgenidze”).
Origins and Naming
Georgian GM Bukhuti Gurgenidze (1933-2008) popularized the setup with …c6 and …d5 in the 1960s. When later practitioners tried the more direct …d5 without …c6, authors dubbed it “Accelerated” in analogy with the Accelerated Dragon. Ukrainian GM Oleg Romanishin was an early adopter of this quicker move order in the 1970s.
Main Ideas for Black
- Challenge the e4-pawn immediately; after 4.exd5 Nf6 recaptures are comfortable because of the pin down the a1–h8 diagonal.
- Maintain queenside flexibility: without the pawn on c6, Black can later play …c5 or …e5 depending on the situation.
- If White avoids the exchange, structures with pawns on e4–d4 vs.…d5 allow Black to blockade d4 with …c6 or …Bg4.
Critical Continuations
- 4.e5 c5 5.dxc5 — White tries to gain space; Black counters on the dark squares.
- 4.Nf3 dxe4 5.Nxe4 Nf6 — transposes to a Pirc-center where Black is fully developed.
- 4.exd5 Nf6 5.Bc4 0-0 — Black gambits the d-pawn for speedy development.
Illustrative Miniature
Black has sacrificed a pawn but seized dark-square control and dynamic play against the white center and king.
Interesting Facts
- Because 3…d5 avoids early …c6, the Accelerated Gurgenidze can transpose to a Scandinavian Defense with colors reversed after e4-exchange lines.
- GM Richard Rapport has employed the line in elite tournaments, proving its viability even at 2800-performance levels.
- The absence of …c6 means the move …c7-c5 often comes as a second pawn lever, mirroring ideas from the Grunfeld and Benoni in a Modern structure.