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

D80

The 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.

For BlackAdvanced

Grünfeld Defence

D80

Ernst Grünfeld's 1922 bombshell: Black lets White build a giant centre, then chips it apart with the g7 bishop.

For BlackAdvanced

Grünfeld Defence: Exchange Variation

D85

The main battleground: the giant centre versus piece pressure — theory past move thirty.

For BlackAdvanced

Grünfeld, Exchange Variation

D85

The main battleground: White's giant centre versus Black's long-diagonal pressure — dynamite since the 1920s.

For WhiteAdvanced

London System

D02

The 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.

For WhiteEffortless

QGD, Orthodox Defence

D55

The Orthodox: the most respected QGD setup of the 20th century — ...c6, ...dxc4 and the eternal ...e5 freeing move.

For BlackIntermediate

QGD, Orthodox Defence, Main

D60

The classical Orthodox tabiya: the ...Nd5 trade simplifies and the ...e5/...c5 wars begin.

For BlackIntermediate

Queen's Gambit

D06

Not a true gambit but the most respected way to fight for the centre: the c4 offer deflects Black's d5 pawn.

For BlackIntermediate

Queen's Gambit Declined

D30

The 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.

For BlackIntermediate

Queen's Gambit Declined

D30

The classical defence to the Queen's Gambit — a century of world championship battles around Black's c5 break.

For BlackIntermediate

Queen's Gambit Declined: Orthodox Defence

D60

The classical main line of the 20th century: the eternal fight over c5 and e5.

For BlackIntermediate

Queen's Pawn Game, 2.Nf3

D02

The home of the London System: Bf4, e3, c3, Nbd2 — plans over moves, and a kingside attack built at leisure.

For WhiteEffortless

Semi-Slav Defence

D43

A 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.

For BlackAdvanced

Semi-Slav Defence

D43

The theory volcano: the Slav's ...c6 plus the QGD's ...e6 — Meran, Botvinnik and Anti-Moscow wars analyzed twenty moves deep.

For BlackAdvanced

Semi-Slav Defence: Meran Variation

D47

The Meran: mutual pawn grabs and forcing lines evaluated to the endgame.

For BlackAdvanced

Semi-Slav, Meran Variation

D47

The Meran: mutual pawn grabs, a6/...c5 counterplay, and forcing lines evaluated to the endgame.

For BlackAdvanced

Slav Defence

D10

The 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.

For BlackIntermediate

Slav Defence

D10

The Slav keeps the light-squared bishop free while supporting d5 with ...c6 — Botvinnik, Kramnik and modern elites approve.

For BlackIntermediate

Closed Game Deep Lines

D30

The 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.

For WhiteIntermediate

Closed Game Deep Lines: Grünfeld, Exchange 8...Nc6

D85

The ...Nc6 development: full pressure on d4 immediately.

For WhiteAdvanced

Closed Game Deep Lines: Grünfeld, Exchange 9.Be3

D85

The Be3 setup: the classical Exchange battleground.

For WhiteAdvanced

Closed Game Deep Lines: QGD, 4.Bf4 Setup

D37

The Bf4 setup: the modern solid treatment.

For WhiteIntermediate

Closed Game Deep Lines: QGD, Orthodox Main 9...Nd5

D60

The ...Nd5 trade: simplifying into the classic Orthodox endgames.

For WhiteIntermediate

Closed Game Deep Lines: QGD, Tartakower 9...c5

D59

The ...c5 break arrives: the full Tartakower middlegame.

For WhiteIntermediate

Closed Game Deep Lines: Semi-Slav, Meran 8.Bd3 a6 9.e4 Setup

D47

The e4 strike: the Meran's central explosion.

For WhiteAdvanced

Closed Game Deep Lines: Slav, Main 6.e3 Main

D18

The castling decision: the full main-line Slav structure.

For WhiteIntermediate

Grünfeld Defence: Exchange, Spassky System

D87

Spassky's f3 fortress: the kingside attack while ...Na5 strikes the centre.

For BlackExpert

Grünfeld Defence: Fianchetto Variation

D90

The positional antidote: Bg2 joins the fight — plans over tactics.

For BlackIntermediate

Grünfeld, Exchange, Classical

D86

The classical Exchange tabiya: the Bc4/Ne2 setup and the eternal e4-d4 central questions.

For WhiteAdvanced

Grünfeld, Exchange, Spassky Variation

D87

The Spassky system: f3 fortifies the centre and launches the kingside attack while ...Na5 strikes.

For WhiteExpert

Grünfeld, Fianchetto Variation

D90

The Fianchetto Variation: White's Bg2 joins the centre fight — positional antidote to the Exchange fireworks.

For WhiteIntermediate

London System: London, Main Setup

D02

The full pyramid: solid development before Ne5 and the kingside build-up.

For WhiteEffortless

QGA, 4.e3

D25

The main QGA: e3/Bxc4 regains the pawn, and the classic ...c5/...a6/...b5 tension defines the middlegame.

For WhiteBeginner-friendly

QGD, 4.Bg5

D50

The pin-variation family gateway: Bg5 pressures f6 and opens the road to Orthodox, Lasker and Tartakower systems.

For BlackIntermediate

QGD, 4.Nf3

D37

The flexible knight-first move order — avoiding the Bg5 pin structures, keeping Ragozin and Semi-Tarrasch options.

For WhiteIntermediate

QGD, Cambridge Springs Defence

D52

Black's venomous ...Qa5 setup: the Bb4 pin paralyses White's queenside and careless moves lose material by force.

For BlackIntermediate

QGD, Exchange Variation

D35

The structural endgame war: White's minority attack and bind against Black's fortress potential.

For WhiteBeginner-friendly

QGD, Lasker Defence

D56

Lasker's clean defensive masterpiece: ...Ne4 kills the bishop pair and unpins the knight — simplicity as strength.

For BlackIntermediate

QGD, Orthodox, Rubinstein Attack

D64

The classical Rubinstein Attack tabiya: Bd3/Qc2/Rc1 harmony — the minority attack machine.

For WhiteIntermediate

QGD, Ragozin Defence

D38

The Ragozin: QGD structure with Nimzo piece play — the modern elite's favourite imbalance generator.

For BlackAdvanced

QGD, Semi-Tarrasch Defence

D40

The Semi-Tarrasch: Black accepts the isolated structure for free piece play and fast development.

For BlackIntermediate

QGD, Tartakower Variation

D58

The Tartakower's ...b6/...Bb7 solves the eternal light-squared bishop problem — Botvinnik and Kasparov approved.

For BlackIntermediate

QGD, Tartakower, Main Line

D59

The full Tartakower tabiya: the ...c5 break with full piece activity versus White's minority attack.

For BlackIntermediate

Queen's Gambit Accepted

D20

The 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.

For BlackBeginner-friendly

Queen's Gambit Accepted

D20

Black takes the c4 pawn at once and challenges White to prove a development lead — clean, classical chess.

For BlackBeginner-friendly

Queen's Gambit Declined: Cambridge Springs Defence

D52

Black's venomous ...Qa5 setup — the Bb4 pin paralyses White's queenside.

For BlackIntermediate

Queen's Gambit Declined: Exchange Variation

D35

The structural endgame war: minority attack and bind versus Black's fortress.

For BlackBeginner-friendly

Queen's Gambit Declined: Lasker Defence

D56

Lasker's simplified fortress: ...Ne4 kills the bishop pair and unpins the knight.

For BlackIntermediate

Queen's Gambit Declined: QGD, 4.Bf4 Setup

D37

The Bf4 setup: the modern solid treatment avoiding the pin structures.

For BlackIntermediate

Queen's Gambit Declined: QGD, Semi-Tarrasch

D40

The Semi-Tarrasch: the isolated pawn accepted for free piece play.

For BlackIntermediate

Queen's Gambit Declined: Ragozin Defence

D38

The modern hybrid: QGD structure with Nimzo-Indian piece play.

For BlackAdvanced

Queen's Gambit Declined: Tarrasch Defence

D32

Tarrasch's free-piece-play philosophy: accept the IQP and never stop hitting the centre.

For BlackIntermediate

Queen's Gambit Declined: Tartakower Variation

D59

The modern classical solution: ...b6/...Bb7 activates the buried bishop.

For BlackIntermediate

Queen's Pawn Game

D00

The umbrella over 1.d4 d5 lines without 2.c4 or 2.Nf3 — including the enterprising Blackmar-Diemer Gambit.

For WhiteBeginner-friendly

Semi-Slav Defence: Botvinnik Main Line

D44

The full Botvinnik chaos: engines, top GMs and forced wins twenty moves deep.

For BlackExpert

Semi-Slav Defence: Botvinnik Variation

D44

The most explosive pawn-structure battle in chess: material versus the monster centre.

For BlackExpert

Semi-Slav Defence: Meran, Nxb5 Sacrifice

D48

The famous Nxb5! sac — material rains but initiative reigns.

For BlackExpert

Semi-Slav, 5.e3

D45

The classical Semi-Slav development: Bd3/Qc2/e4 plans versus Black's ...dxc4 and ...b5 counterplay.

For WhiteIntermediate

Semi-Slav, 6.Bd3

D46

The Meran precursor: the bishop retreats after ...b5 and the a6/e4 middlegame begins.

For WhiteAdvanced

Semi-Slav, Botvinnik Variation

D44

The most explosive pawn-structure battle in chess: Black grabs material while White builds a monster centre.

For BlackExpert