ECO → PSCC correspondence


Here I'll write PSCC (Pawn Structure Classification Codes) for all basic ECO codes. The inverse correspondence is more interesting. It will regroup openings by pawn structures and I'll post it later. peshka.png The initial pawn structure will be denoted by I. Notice also that PSCC can be divided into white and black parts. settings.png


N.B. √ denotes the (pawn structure of the) root of the opening tree of a given type. For example: √(A01) = 1B.


A01 1B [1B vs I] Nimzo-Larsen attack [√: Hippo vs Hippo]

A02 2F [2F vs IBird's opening [√: Normal vs Hippo]

A03 2Fd [2F vs 2dBird's opening: Dutch variation [√: Normal vs Normal]

A04-05 I [vs IRéti opening [√: Hippo vs Hippo]

A06 2d [vs 2dRéti: Queen's pawn [√: Hippo vs Normal]

A07 2d1G [1G vs 2dKing's Indian attack (KIA) [√: Hippo vs Normal]

A08 2cd1G [1G vs 2cdKIA: Sicilian variation [√: Hippo vs Normal]

A09 2Cd [2C vs 2dRéti: English attack [√: Normal vs Normal]

A10 2C [2C vs I] English opening [√: Normal vs Hippo]

A11 2C1c [2C vs 1cEnglish: Caro-Kann system [√: Normal vs Hippo]

A12 2Cd1Bc [2C1B vs 2d1cAnglo-Slav: Bogoljubov variation III [√: Normal vs Normal]

A13 2C1e [2C vs 1eEnglish: Agincourt defense [√: Normal vs Hippo]

A14 2Cd1Ge [2C1G vs 2d1eEnglish: Neo-Catalan declined [√: Normal vs Normal]

A15-16 2C [2C vs IAnglo-Indian [√: Normal vs Hippo]

A17 2C1e [2C vs 1eAnglo-Indian: Hedgehog system [√: Normal vs Hippo]

A18 2CE1e [2CE vs 1eAnglo-Indian: Mikenas-Carls variation [√: Normal vs Hippo]

A19 2CEc1e [2CE vs 2c1eAnglo-Indian: Mikenas-Carls: Sicilian variation [√: Normal vs Normal]

A20-22 2Ce [2C vs 2eKing's English  [√: Normal vs Normal]

A23 2Ce1Gc [2C1G vs 2e1cKing's English: Bremen system: Keres variation [√: Normal vs Normal]

A24 2Ce1Gg [2C1G vs 2e1gKing's English: Bremen system with g6 [√: Normal vs Normal]

A25 2Ce [2C vs 2eReversed Closed Sicilian [√: Normal vs Normal]

A26 2Ce [2C vs 2eKing's English: closed system [√: Normal vs Normal]

A27 2Ce [2C vs 2eKing's English: Three Knights system [√: Normal vs Normal]

A28 2Ce [2C vs 2eKing's English: Four Knights system [√: Normal vs Normal]

A29 2Ce [2C vs 2e1GKing's English: Four Knights system: kingside fianchetto [√: Normal vs Normal]

A30 2Cc [2C vs 2cSymmetrical English [√: Normal vs Normal]

A31 2CDc [2CD vs 2cSymmetrical English: Benoni formation [√: Normal vs Normal]

A32-33 6Dc2C1e [6D2C vs 6c1eSymmetrical English: Anti-Benoni [√: Normal vs Normal, Dc-Exchange]

A34 2Cc [2C vs 2cSymmetrical English: Normal variation [√: Normal vs Normal]

A35 2Cc [2C vs 2cSymmetrical English: Two Knights variation [√: Normal vs Normal]

A36 2Cc1G [2C1G vs 2cSymmetrical English: Fianchetto variation [√: Normal vs Normal]

A37-38 2Cc1Gg [2C1G vs 2c1g] Symmetrical English: Symmetrical Fianchetto [√: Normal vs Normal]

A39 2CDc1Gg [2CD1G vs 2c1gSymmetrical English: Mecking variation [√: Normal vs Normal]

A40 2D [2D vs IQueen's Pawn (QP) opening [√: Normal vs Hippo]

A41 2D1d [2D vs 1dQP: Loewe defense [√: Normal vs Hippo]

A42 2CDE1dg [2CDE vs 1dgModern defense: Averbakh system [√: Normal vs Hippo]

A43 2Dc [2D vs 2cOld Benoni [√: Normal vs Normal]

A44 3D2ce [3D vs 2ceOld Benoni: Advance variation with e5 [√: Advance vs Normal]

A45-46 2D [2D vs IIndian game [√: Normal vs Hippo]

A47 2D1b [2D vs 1bQueen's Indian defense (QID) [√: Normal vs Hippo]

A48 2D1g [2D vs 1g East Indian defense [√: Normal vs Hippo]

A49 2D1Gg [2D1G vs 1gIndian game: Przepiorka variation [√: Normal vs Hippo]

A50 2CD [2CD vs IIndian game: Normal variation [√: Normal vs Hippo]

A51 2CDe [2CD vs 2eBudapest gambit [√: Normal vs Normal]

A52 6d3E*2C0D [3E*2C0D vs 6dBudapest gambit accepted with Ng4 [√: Advance vs Normal]

A53 2CD1d [2CD vs 1dOld Indian defense [√: Normal vs Hippo]

A54 2CDe1d [2CD vs 2e1dOld Indian defense: Ukrainian variation [√: Normal vs Normal]

A55 2CDEe1d [2CDE vs 2e1dOld Indian defense: main line [√: Normal vs Normal]

A56 2CDc [2CD vs 2dBenoni defense [√: Normal vs Normal]

A57 3D2Cbc [3D2C vs 2bcBenko gambit [√: Advance vs Normal]

A58 6ab4A*3D2c0C [4A*3D0C vs 6ab2cBenko gambit: Fully Accepted variation [√: Advance vs Normal]

A59 6Cab3D2Ec1d [6C3D2E vs 6ab2c1dBenko gambit: Fully Accepted variation #2 [√: Advance vs Normal]

A60 3D2Cc1e [3D2C vs 2c1e] Benoni defense [√: Advance vs Normal]

A61 6Ce3D2c1dg [6C3D vs 6e2c1dg] Benoni defense [√: Advance vs Normal, Ce-exchange]

A62-63 6Ce3D2c1Gdg [6C3D1G vs 6e2c1dg] Benoni defense: fianchetto variation [√: Advance vs Normal, Ce-exchange]

A64 6Ce3D2Ac1Gadg [6C3D2A1G vs 6e2c1dg] Benoni defense: fianchetto variation [√: Advance vs Normal, Ce-exchange]

A65 6Ce3D2Ec1d [6C3D2E vs 6e2c1d] Benoni defense with 6. e4 [√: Advance vs Normal, Ce-exchange]

A66 6Ce3D2EFc1dg [6C3D2EF vs 6e2c1dg] Benoni defense: pawn storm [√: Advance vs Normal, Ce-exchange]

A67 6Ce3D2EFc1dg [6C3D2EF vs 6e2c1dg] Benoni defense: Taimanov variation [√: Advance vs Normal, Ce-exchange]

A68 6Ce3D2EFc1dg [6C3D2EF vs 6e2c1dg] Benoni defense: four pawns attack [√: Advance vs Normal, Ce-exchange]

A69 6Ce3D2EFc1dg [6C3D2EF vs 6e2c1dg] Benoni defense: four pawns attack: main line [√: Advance vs Normal, Ce-exchange]

A70-73 6Ce3D2Ec1dg [6C3D2E vs 6e2c1dg] Benoni defense with e4 and Nf3 [√: Advance vs Normal, Ce-exchange]

A74 6Ce3D2AEc1adg [6C3D2AE vs 6e2c1adg] Benoni defense with 9...a6 and 10. a4 [√: Advance vs Normal, Ce-exchange]


(to be continued)


All right, it progresses smoothly, I've just finished English variations. happy.png The main opening systems, that appeared so far, is 2Cc-hierarchy (Symmetrical English) and 2Ce-hierarchy (King's English). settings.png


A40-A59 are added. settings.png


Complex codes can be divided into white and black parts in order to be more readable.


Example 1. The PSCC of fully accepted Benko gambit #2 (A59):

6Cab3D2Ec1d = 6C3D2E vs 6ab2c1d.

Here the symbol 6 corresponds to files with missing pawns, each such pawn contributes +6 to the total pawn height. peshka.png



I started to indicate the division of PSCC codes into white and black parts as well as Hippo/Normal/Advance categories of roots of opening trees with given ECO codes. settings.png


I started to indicate Exchange variations, corresponding to PSCC [6... vs 6...], for example, A32-33. settings.png


A61 gives the first example of Ce-exchange. peshka.png




A01-A70 are converted. openings.png