ECO Volume D · D00–D99
Volume D — Closed & Semi-Closed Games
The land of 1.d4 d5: the Queen's Gambit complex, the steel of the Slav, the classical QGD and the dynamic Grünfeld Defence. Queen's Gambit, Slav & Grünfeld.
Grünfeld Defence
D80The Grünfeld is hypermodern dynamism in its purest form: Black hands White the entire centre, then attacks it from the flanks with the mighty g7-bishop and relentless piece pressure. It is the opening of Fischer's Game of the Century and of every engine-era warrior.
Grünfeld Defence
D80Ernst Grünfeld's 1922 bombshell: Black lets White build a giant centre, then chips it apart with the g7 bishop.
Grünfeld Defence: Exchange Variation
D85The main battleground: the giant centre versus piece pressure — theory past move thirty.
Grünfeld, Exchange Variation
D85The main battleground: White's giant centre versus Black's long-diagonal pressure — dynamite since the 1920s.
London System
D02The internet's favourite opening: Bf4, e3, c3, Nbd2 — a low-theory system where the plans matter more than the moves. White attacks on the kingside while Black expands on the other wing; understanding beats memorisation every time.
QGD, Orthodox Defence
D55The Orthodox: the most respected QGD setup of the 20th century — ...c6, ...dxc4 and the eternal ...e5 freeing move.
QGD, Orthodox Defence, Main
D60The classical Orthodox tabiya: the ...Nd5 trade simplifies and the ...e5/...c5 wars begin.
Queen's Gambit
D06Not a true gambit but the most respected way to fight for the centre: the c4 offer deflects Black's d5 pawn.
Queen's Gambit Declined
D30The Queen's Gambit Declined is the most respected defence in chess history — every world champion has defended it and attacked it. Black accepts slight cramping for a rock-solid structure, and the middlegames test deep understanding: minority attacks versus c5 breaks, light-square wars and endgame technique.
Queen's Gambit Declined
D30The classical defence to the Queen's Gambit — a century of world championship battles around Black's c5 break.
Queen's Gambit Declined: Orthodox Defence
D60The classical main line of the 20th century: the eternal fight over c5 and e5.
Queen's Pawn Game, 2.Nf3
D02The home of the London System: Bf4, e3, c3, Nbd2 — plans over moves, and a kingside attack built at leisure.
Semi-Slav Defence
D43A hybrid fortress: the Slav's ...c6 plus the QGD's ...e6 create the most theory-heavy triangle in chess. Meran, Botvinnik and Anti-Moscow lines are analyzed twenty moves deep — the Semi-Slav is where opening preparation became a profession.
Semi-Slav Defence
D43The theory volcano: the Slav's ...c6 plus the QGD's ...e6 — Meran, Botvinnik and Anti-Moscow wars analyzed twenty moves deep.
Semi-Slav Defence: Meran Variation
D47The Meran: mutual pawn grabs and forcing lines evaluated to the endgame.
Semi-Slav, Meran Variation
D47The Meran: mutual pawn grabs, a6/...c5 counterplay, and forcing lines evaluated to the endgame.
Slav Defence
D10The Slav keeps Black's light-squared bishop free while supporting the d5 stronghold with ...c6 — a defence that carried Botvinnik, Kramnik and modern elite players to the top. Rock solid with real counterpunch.
Slav Defence
D10The Slav keeps the light-squared bishop free while supporting d5 with ...c6 — Botvinnik, Kramnik and modern elites approve.
Closed Game Deep Lines
D30The deep-line archive of Volume D: named sub-variations of the QGD, Slav, Semi-Slav, QGA, Tarrasch and Grünfeld — the lines that decide real games once both players know the first ten moves.
Closed Game Deep Lines: Grünfeld, Exchange 8...Nc6
D85The ...Nc6 development: full pressure on d4 immediately.
Closed Game Deep Lines: Grünfeld, Exchange 9.Be3
D85The Be3 setup: the classical Exchange battleground.
Closed Game Deep Lines: QGD, 4.Bf4 Setup
D37The Bf4 setup: the modern solid treatment.
Closed Game Deep Lines: QGD, Orthodox Main 9...Nd5
D60The ...Nd5 trade: simplifying into the classic Orthodox endgames.
Closed Game Deep Lines: QGD, Tartakower 9...c5
D59The ...c5 break arrives: the full Tartakower middlegame.
Closed Game Deep Lines: Semi-Slav, Meran 8.Bd3 a6 9.e4 Setup
D47The e4 strike: the Meran's central explosion.
Closed Game Deep Lines: Slav, Main 6.e3 Main
D18The castling decision: the full main-line Slav structure.
Grünfeld Defence: Exchange, Spassky System
D87Spassky's f3 fortress: the kingside attack while ...Na5 strikes the centre.
Grünfeld Defence: Fianchetto Variation
D90The positional antidote: Bg2 joins the fight — plans over tactics.
Grünfeld, Exchange, Classical
D86The classical Exchange tabiya: the Bc4/Ne2 setup and the eternal e4-d4 central questions.
Grünfeld, Exchange, Spassky Variation
D87The Spassky system: f3 fortifies the centre and launches the kingside attack while ...Na5 strikes.
Grünfeld, Fianchetto Variation
D90The Fianchetto Variation: White's Bg2 joins the centre fight — positional antidote to the Exchange fireworks.
London System: London, Main Setup
D02The full pyramid: solid development before Ne5 and the kingside build-up.
QGA, 4.e3
D25The main QGA: e3/Bxc4 regains the pawn, and the classic ...c5/...a6/...b5 tension defines the middlegame.
QGD, 4.Bg5
D50The pin-variation family gateway: Bg5 pressures f6 and opens the road to Orthodox, Lasker and Tartakower systems.
QGD, 4.Nf3
D37The flexible knight-first move order — avoiding the Bg5 pin structures, keeping Ragozin and Semi-Tarrasch options.
QGD, Cambridge Springs Defence
D52Black's venomous ...Qa5 setup: the Bb4 pin paralyses White's queenside and careless moves lose material by force.
QGD, Exchange Variation
D35The structural endgame war: White's minority attack and bind against Black's fortress potential.
QGD, Lasker Defence
D56Lasker's clean defensive masterpiece: ...Ne4 kills the bishop pair and unpins the knight — simplicity as strength.
QGD, Orthodox, Rubinstein Attack
D64The classical Rubinstein Attack tabiya: Bd3/Qc2/Rc1 harmony — the minority attack machine.
QGD, Ragozin Defence
D38The Ragozin: QGD structure with Nimzo piece play — the modern elite's favourite imbalance generator.
QGD, Semi-Tarrasch Defence
D40The Semi-Tarrasch: Black accepts the isolated structure for free piece play and fast development.
QGD, Tartakower Variation
D58The Tartakower's ...b6/...Bb7 solves the eternal light-squared bishop problem — Botvinnik and Kasparov approved.
QGD, Tartakower, Main Line
D59The full Tartakower tabiya: the ...c5 break with full piece activity versus White's minority attack.
Queen's Gambit Accepted
D20The QGA takes the c4 pawn at once and challenges White to prove a development lead — clean, classical, and full of famous endgame structures. Honest chess with no forced draws and no cheap traps.
Queen's Gambit Accepted
D20Black takes the c4 pawn at once and challenges White to prove a development lead — clean, classical chess.
Queen's Gambit Declined: Cambridge Springs Defence
D52Black's venomous ...Qa5 setup — the Bb4 pin paralyses White's queenside.
Queen's Gambit Declined: Exchange Variation
D35The structural endgame war: minority attack and bind versus Black's fortress.
Queen's Gambit Declined: Lasker Defence
D56Lasker's simplified fortress: ...Ne4 kills the bishop pair and unpins the knight.
Queen's Gambit Declined: QGD, 4.Bf4 Setup
D37The Bf4 setup: the modern solid treatment avoiding the pin structures.
Queen's Gambit Declined: QGD, Semi-Tarrasch
D40The Semi-Tarrasch: the isolated pawn accepted for free piece play.
Queen's Gambit Declined: Ragozin Defence
D38The modern hybrid: QGD structure with Nimzo-Indian piece play.
Queen's Gambit Declined: Tarrasch Defence
D32Tarrasch's free-piece-play philosophy: accept the IQP and never stop hitting the centre.
Queen's Gambit Declined: Tartakower Variation
D59The modern classical solution: ...b6/...Bb7 activates the buried bishop.
Queen's Pawn Game
D00The umbrella over 1.d4 d5 lines without 2.c4 or 2.Nf3 — including the enterprising Blackmar-Diemer Gambit.
Semi-Slav Defence: Botvinnik Main Line
D44The full Botvinnik chaos: engines, top GMs and forced wins twenty moves deep.
Semi-Slav Defence: Botvinnik Variation
D44The most explosive pawn-structure battle in chess: material versus the monster centre.
Semi-Slav Defence: Meran, Nxb5 Sacrifice
D48The famous Nxb5! sac — material rains but initiative reigns.
Semi-Slav, 5.e3
D45The classical Semi-Slav development: Bd3/Qc2/e4 plans versus Black's ...dxc4 and ...b5 counterplay.
Semi-Slav, 6.Bd3
D46The Meran precursor: the bishop retreats after ...b5 and the a6/e4 middlegame begins.
Semi-Slav, Botvinnik Variation
D44The most explosive pawn-structure battle in chess: Black grabs material while White builds a monster centre.