B00–C44WhiteKing's Pawn Game1. e4 38 named linesWayward Queen AttackGunderam GambitDamiano DefenseLeonardis Variation
A40–D05WhiteQueen's Pawn Game1. d4 59 named linesZukertort VariationSymmetrical VariationModern DefenseColle System
A43–E60BlackIndian Defense1. d4 Nf6 52 named linesNormal VariationWest Indian DefenseAnti-Nimzo-IndianKnights Variation
B20–B99BlackSicilian Defense1. e4 c5 370 named linesModern VariationsOld SicilianNajdorf VariationFrench Variation
E60–E99WhiteKing's Indian Defense1. d4 Nf6 2. c4 g6 3. Nc3 112 named linesNormal VariationNormal VariationOrthodox VariationOrthodox Variation
C60–C99WhiteRuy Lopez1. e4 e5 2. Nf3 Nc6 3. Bb5 230 named linesMorphy DefenseMorphy DefenseClosedClosed
D02–D69BlackQueen's Gambit Declined1. d4 d5 2. c4 e6 163 named linesQueen's Knight VariationNormal DefenseThree Knights VariationModern Variation
A10–C20WhiteEnglish Opening1. c4 146 named linesSymmetrical VariationKing's English VariationSymmetrical VariationAnglo-Indian Defense
C00–C19BlackFrench Defense1. e4 e6 191 named linesNormal VariationPaulsen VariationTarrasch VariationWinawer Variation
C50–C59WhiteItalian Game1. e4 e5 2. Nf3 Nc6 3. Bc4 171 named linesTwo Knights DefenseGiuoco PianoEvans GambitClassical Variation
E12–E59BlackNimzo-Indian Defense1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 100 named linesRubinstein SystemNormal VariationClassical VariationNormal Variation
A40–A79BlackBenoni Defense1. d4 Nf6 2. c4 c5 53 named linesModern VariationKing's Pawn LineClassical VariationOld Benoni
B10–B19BlackCaro-Kann Defense1. e4 c6 103 named linesMain LineExchange VariationPanov AttackClassical Variation
D10–D19BlackSlav Defense1. d4 d5 2. c4 c6 48 named linesModern LineThree Knights VariationTwo Knights AttackAlapin Variation
A04–A41WhiteZukertort Opening1. Nf3 47 named linesSicilian InvitationDutch VariationLisitsyn GambitTennison Gambit
A56–E60BlackGrünfeld Defense1. d4 Nf6 2. c4 g6 3. Nc3 d5 59 named linesThree Knights VariationThree Knights VariationExchange VariationCounterthrust Variation
A80–A99BlackDutch Defense1. d4 f5 68 named linesNormal VariationFianchetto VariationClassical VariationClassical Variation
E12–E19BlackQueen's Indian Defense1. d4 Nf6 2. c4 e6 3. Nf3 b6 48 named linesFianchetto VariationTraditional VariationClassical VariationPetrosian Variation
D20–D29BlackQueen's Gambit Accepted1. d4 d5 2. c4 dxc4 51 named linesNormal VariationNormal VariationClassical DefenseShowalter Variation
C33–C39BlackKing's Gambit Accepted1. e4 e5 2. f4 exf4 136 named linesKing's Knight's GambitKing's Knight's GambitKing's Knight's GambitKing's Knight's Gambit
D30–D49BlackSemi-Slav Defense1. d4 d5 2. c4 c6 3. Nf3 Nf6 4. Nc3 e6 59 named linesMain LineNormal VariationMain LineSemi-Meran Variation
B02–B05BlackAlekhine Defense1. e4 Nf6 56 named linesNormal VariationModern VariationFour Pawns AttackExchange Variation
C46WhiteThree Knights Opening1. e4 e5 2. Nf3 Nc6 3. Nc3 6 named linesSteinitz DefenseWinawer DefenseSchlechter VariationSteinitz-Rosenthal Variation
C44–C45WhiteScotch Game1. e4 e5 2. Nf3 Nc6 3. d4 53 named linesScotch GambitClassical VariationSteinitz VariationHorwitz Attack
C25–C29WhiteVienna Game1. e4 e5 2. Nc3 41 named linesFalkbeer VariationMax Lange DefenseStanley VariationVienna Gambit
C47–C50BlackFour Knights Game1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 45 named linesSpanish VariationScotch VariationScotch Variation AcceptedHalloween Gambit
B01BlackScandinavian Defense1. e4 d5 45 named linesModern VariationMieses-Kotroc VariationModern VariationMain Line
B07–B09BlackPirc Defense1. e4 d6 28 named linesClassical VariationClassical VariationAustrian AttackAustrian Attack
C42–C43BlackPetrov's Defense1. e4 e5 2. Nf3 Nf6 48 named linesModern AttackClassical AttackModern AttackStafford Gambit
C23–C43WhiteBishop's Opening1. e4 e5 2. Bc4 40 named linesBerlin DefenseBoi VariationPonziani GambitUrusov Gambit
D32–D34BlackTarrasch Defense1. d4 d5 2. c4 e6 3. Nc3 c5 26 named linesTwo Knights VariationRubinstein SystemPrague VariationClassical Variation
A04–B27BlackModern Defense1. e4 g6 39 named linesStandard LineAverbakh SystemStandard DefenseModern Pterodactyl
A02–B21WhiteBird Opening1. f4 29 named linesDutch VariationFrom's GambitWilliams GambitWagner-Zwitersch Gambit
D00WhiteBlackmar-Diemer Gambit1. d4 d5 2. e4 18 named linesvon Popiel GambitLemberger CountergambitZeller DefenseBlackmar Gambit
C41BlackPhilidor Defense1. e4 e5 2. Nf3 d6 44 named linesNimzowitsch VariationLion VariationExchange VariationHanham Variation
A57–A59BlackBenko Gambit1. d4 Nf6 2. c4 c5 3. d5 b5 8 named linesZaitsev SystemFianchetto VariationNd2 VariationMutkin Countergambit
D70–D79BlackNeo-Grünfeld Defense1. d4 Nf6 2. c4 g6 3. g3 d5 13 named linesClassical VariationDelayed Exchange VariationUltra-Delayed Exchange VariationExchange Variation
A45WhiteTrompowsky Attack1. d4 Nf6 2. Bg5 10 named linesEdge VariationClassical DefenseRaptor VariationPoisoned Pawn Variation
A05–A08WhiteKing's Indian Attack1. Nf3 d5 2. g3 17 named linesSicilian VariationSicilian VariationFrench VariationSymmetrical Defense
A57–A59BlackBenko Gambit Accepted1. d4 Nf6 2. c4 c5 3. d5 b5 4. cxb5 a6 10 named linesFully Accepted VariationYugoslavKing Walk VariationFianchetto Variation
B00BlackNimzowitsch Defense1. e4 Nc6 43 named linesDeclined VariationScandinavian VariationKennedy VariationWilliams Variation
A00–C31WhiteVan Geet Opening1. Nc3 33 named linesReversed NimzowitschBerlin GambitDougherty GambitNowokunski Gambit
A00–A05WhitePolish Opening1. b4 24 named linesKing's Indian VariationTartakower GambitOutflank VariationGerman Defense
E11BlackBogo-Indian Defense1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 17 named linesNimzowitsch VariationRetreat VariationGrünfeld VariationRetreat Variation
C20–C22WhiteCenter Game1. e4 e5 2. d4 19 named linesNormal VariationPaulsen Attack VariationBerger VariationKieseritzky Variation
C40–C44BlackLatvian Gambit1. e4 e5 2. Nf3 f5 17 named linesMayet AttackCorkscrew CountergambitMason CountergambitDiepstraten Countergambit
D00BlackBlackmar-Diemer Gambit Accepted1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 21 named linesRyder GambitBogoljubow DefenseEuwe DefenseTeichmann Defense
A00–A07WhiteHungarian Opening1. g3 20 named linesReversed AlekhineDutch DefenseParis GambitIndian Defense
A41–A55WhiteOld Indian Defense1. d4 d6 2. c4 14 named linesUkrainian VariationTwo Knights VariationNormal VariationJanowski Variation
A00WhiteGrob Opening1. g4 20 named linesGrob GambitKeene DefenseGrob Gambit DeclinedRomford Countergambit
A09–A14WhiteRéti Opening1. Nf3 d5 2. c4 17 named linesAdvance VariationRéti AcceptedZilbermints GambitPenguin Variation
C30–C32BlackKing's Gambit Declined1. e4 e5 2. f4 d5 53 named linesFalkbeer Countergambit AcceptedClassical VariationClassical VariationPanteldakis Countergambit
C44WhitePonziani Opening1. e4 e5 2. Nf3 Nc6 3. c3 16 named linesJaenisch CounterattackPonziani CountergambitJaenisch CounterattackSpanish Variation
C25WhiteVienna Gambit, with Max Lange Defense1. e4 e5 2. Nc3 Nc6 3. f4 15 named linesKnight VariationPierce GambitSteinitz GambitHamppe-Allgaier Gambit
A00WhiteKádas Opening1. h4 9 named linesKádas GambitKoola-Koola VariationSchneider GambitBeginner's Trap
B00BlackSt. George Defense1. e4 a6 4 named linesZilbermints GambitPolish VariationSan Jorge Variation
A01–A06WhiteNimzo-Larsen Attack1. b3 18 named linesClassical VariationModern VariationModern VariationDutch Variation
A40BlackEnglund Gambit1. d4 e5 9 named linesMain LineStockholm VariationHartlaub-Charlick GambitMosquito Gambit
B00BlackOwen Defense1. e4 b6 8 named linesMatovinsky GambitGuatemala DefenseNaselwaus GambitSmith Gambit
A40BlackMikenas Defense1. d4 Nc6 4 named linesCannstatter VariationLithuanian VariationPozarek Gambit
D01WhiteRichter-Veresov Attack1. d4 Nf6 2. Nc3 d5 3. Bg5 8 named linesTwo Knights SystemBoyce DefenseRichter VariationVeresov Variation
C21BlackDanish Gambit Accepted1. e4 e5 2. d4 exd4 3. c3 dxc3 7 named linesClassical DefenseSvenonius DefenseChigorin DefenseCopenhagen Defense
A40BlackEnglish Defense1. d4 b6 7 named linesEastbourne GambitPerrin VariationHartlaub Gambit DeclinedHartlaub Gambit Accepted
E10BlackBlumenfeld Countergambit1. d4 Nf6 2. c4 e6 3. Nf3 c5 4. d5 b5 3 named linesDuz-Khotimirsky VariationSpielmann Variation
D00BlackBlackmar-Diemer Gambit Declined1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 Bf5 8 named linesWeinsbach DefenseBrombacher CountergambitElbert CountergambitGedult Defense
A41–C00WhiteRat Defense1. e4 d6 2. f4 11 named linesEnglish RatPetruccioli AttackSpike AttackAntal Defense
D05WhiteRubinstein Opening1. d4 Nf6 2. Nf3 e6 3. e3 c5 4. Bd3 d5 5. b3 6 named linesSemi-Slav DefenseSemi-Slav DefenseBogoljubow DefenseClassical Defense
C40BlackElephant Gambit1. e4 e5 2. Nf3 d5 4 named linesMaróczy GambitPaulsen CountergambitWasp Variation
A57WhiteBenko Gambit Declined1. d4 Nf6 2. c4 c5 3. d5 b5 4. Nf3 6 named linesBishop AttackHjørring CountergambitPseudo-SämischQuiet Line
A40WhiteEnglund Gambit Declined1. d4 e5 2. d5 7 named linesReversed AlekhineReversed KrebsReversed FrenchReversed Brooklyn
C40WhiteLatvian Gambit Accepted1. e4 e5 2. Nf3 f5 3. exf5 9 named linesMain LineBilguer VariationFoltys-Leonhardt VariationFoltys Variation
A04–A40BlackColle System1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 Qa5+ 3 named linesRhamphorhynchus VariationSiroccopteryx Variation
A00WhiteFormation1. a3 e5 2. b3 d5 3. c3 Nf6 4. d3 Nc6 5. e3 Bd6 6. f3 O-O 7. g3 2 named linesShy Attack
E10BlackBlumenfeld Countergambit Accepted1. d4 Nf6 2. c4 e6 3. Nf3 c5 4. d5 b5 5. dxe6 fxe6 6. cxb5 d5 1 named line