Editing Encyclopaedia of Chess Openings

{{Short description|Reference work on chess openings}}
{{Italic title}}
[[File:Encyclopaedia of Chess Openings (volume E; 1978 edition).jpg|right|thumb|First edition of ''ECO'' volume E. The title is given in eight languages. In the center are the two openings included in the volume: 1.d4 Nf6 2.c4 e6; and  1.d4 Nf6 2.c4 g6 without (symbol ┘) an early ...d7–d5.]]

The '''''Encyclopaedia of Chess Openings''''' ('''''ECO''''') is a reference work describing the state of [[Chess theory#Opening theory|opening theory]] in [[chess]], originally published in five volumes from 1974 to 1979 by the [[Socialist Federal Republic of Yugoslavia|Yugoslavian]] company Šahovski Informator ([[Chess Informant]]). It is currently undergoing its fifth edition. ''ECO'' may also refer to the opening classification system used by the encyclopedia.
{{AN chess|pos=toc}}

==Overview==
Both ''ECO'' and ''[[Chess Informant]]'' are published by the [[Belgrade]]-based company [[Chess Informant|Šahovski Informator]]. The moves are taken from thousands of master games and from published analysis in ''Informant'' and compiled by the editors, most of whom are [[Grandmaster (chess)|grandmasters]], who select the lines which they consider most relevant or critical. The chief editor since the first edition has been [[Aleksandar Matanović]] (1930-2023). The openings are provided in an [[chess opening theory table|''ECO'' table]] that concisely presents the opening lines considered most critical by the editors. ''ECO'' covers the openings in more detail than rival single volume publications such as ''[[Modern Chess Openings]]'' and ''[[Nunn's Chess Openings]]'', but in less detail than specialized opening books.

The books are intended for an international audience and contain only a small amount of text, which is in several languages. The bulk of the content consists of diagrams of positions and chess moves, annotated with [[Chess annotation symbols|symbols]], many of them developed by Chess Informant. [[Chess Informant]] pioneered the use of [[Algebraic notation (chess)#Naming the pieces|Figurine Algebraic Notation]] to avoid the use of initials for the names of the pieces, which vary between languages.

Instead of the traditional names for the openings, ''ECO'' has developed a coding system that has also been adopted by other [[chess publications]]. There are five main categories, "A" to "E", corresponding to the five volumes of the earlier editions, each of which is further subdivided into 100 subcategories, for a total of 500 codes. The term "''ECO''" is often used as a shorthand for this coding system. ''ECO'' code is a registered trademark of [[Chess Informant]].

==Openings covered==

===Volume A: [[Flank opening]]s===
* [[English Opening]]
* [[Benoni Defence]]
* [[Dutch Defence]]
* [[Réti Opening]]
* [[Benko Gambit]]
* [[Old Indian Defence]]
* [[Bird's Opening]]
* Anti-[[Indian Defence|Indian]] systems ([[Trompowsky Attack]], [[Torre Attack]], [[Richter–Veresov Attack]])
* [[Irregular chess opening|Irregular openings]], etc.

===Volume B: [[Semi-Open Game]]s other than the French Defence===
* [[Sicilian Defence]]
* [[Caro-Kann Defence]]
* [[Pirc Defence]]
* [[Alekhine's Defence]]
* [[Modern Defence]]
* [[Scandinavian Defence]], etc.

===Volume C: [[Open Game]]s and the French Defence===
* [[Ruy Lopez]]
* [[French Defence]]
* [[Petrov's Defence]]
* [[Vienna Game]]
* [[Centre Game]]
* [[King's Gambit]]
* [[Philidor Defence]]
* [[Italian Game|Italian]] ([[Giuoco Piano]], [[Evans Gambit]], [[Hungarian Defence]], and [[Two Knights Defence|Two Knights]])
* [[Scotch Game]]
* [[Four Knights Game]], etc.
* [[King's Pawn Opening]], etc. (covers unusual/rare 1. e4 openings such as the [[Elephant Gambit]] and [[Ponziani Opening]]).

===Volume D: [[Closed Game]]s and [[Semi-Closed Game]]s===
:(''including Grünfeld Defence but not other Indian Defenses'')
* [[Queen's Gambit]]
** [[Queen's Gambit Accepted|Accepted]]
** [[Queen's Gambit Declined|Declined]] ([[Slav Defense|Slav]], [[Queen's Gambit Declined|Orthodox]], [[Tarrasch Defense|Tarrasch]], [[Tartakower Defense|Tartakower]], [[Albin Countergambit]], etc.)
* [[Grünfeld Defence]]
* [[Queen's Pawn Game]], etc.

===Volume E: [[Indian Defence]]s===
:(''other than Grünfeld Defence and Old Indian Defence'')
* [[Nimzo-Indian Defence]]
* [[Queen's Indian Defence]]
* [[King's Indian Defence]]
* [[Catalan Opening]]
* [[Bogo-Indian Defence]], etc.

== Main ''ECO'' codes ==
{{main|List of chess openings}}

===A===
* White first moves other than 1.e4, 1.d4 (A00–A39)
* 1.d4 without 1...d5, 1...Nf6 or 1...f5: Atypical replies to 1.d4 (A40–A44)
* 1.d4 Nf6 without 2.c4: Atypical replies to 1...Nf6 (A45–A49)
* 1.d4 Nf6 2.c4 without 2...e6, 2...g6: Atypical [[Indian Defence|Indian systems]] (A50–A79)
* 1.d4 f5: [[Dutch Defence]] (A80–A99)

===B===
* 1.e4 without 1...c6, 1...c5, 1...e6, 1...e5 (B00–B09)
* 1.e4 c6: [[Caro–Kann Defence]] (B10–B19)
* 1.e4 c5: [[Sicilian Defence]] (B20–B99)

===C===
* 1.e4 e6: [[French Defence]] (C00–C19)
* 1.e4 e5: [[Open Game|Double King Pawn games]] (C20–C99)

===D===
* 1.d4 d5: [[Closed Game|Double Queen Pawn]] games (D00–D69)
* 1.d4 Nf6 2.c4 g6 with 3...d5: [[Grünfeld Defence]] (D70–D99)

===E===
* 1.d4 Nf6 2.c4 e6: [[Indian Defence|Indian systems]] with ...e6 (E00–E59)
* 1.d4 Nf6 2.c4 g6 without 3...d5: Indian systems with ...g6 (except Grünfeld) (E60–E99)

==First edition==
The first edition was published in the following years:
* Volume A: 1979
* Volume B: 1975
* Volume C: 1974
* Volume D: 1976
* Volume E: 1978

{| <!-- meta-table to contain the tables for each volume -->
|-valign="top"
|
{| class="wikitable sortable"
|+ Volume D (1976)
! Code !! Author
|-
| 00–01 || [[Vladimir Bagirov|Bagirov, Vladimir]]
|-
| 94–95 || [[Vladimir Bagirov|Bagirov, Vladimir]]
|-
| 60–65 || [[Gedeon Barcza|Barcza, Gedeon]]
|-
| 60–65 || [[Tibor Flórián (chess player)|Florian, Tibor]]
|-
| 70–79 || [[Mikhail Botvinnik|Botvinnik, Mikhail]]
|-
| 98–99 || [[Mikhail Botvinnik|Botvinnik, Mikhail]]
|-
| 70–79 || [[Lev Abramov|Abramov, Lev]]
|-
| 98–99 || [[Lev Abramov|Abramov, Lev]]
|-
| 56–57 || [[Enver, Bukić|Bukić, Enver]]
|-
| 02–05 || [[Srđan Cvetković|Cvetković, Srđan]]
|-
| 02–05 || [[Vladimir Sokolov (chess player)|Sokolov, Vladimir]]
|-
| 31–32 || [[Max Euwe|Euwe, Max]]
|-
| 50–55 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 45–46 || [[Florin Gheorghiu|Gheorghiu, Florin]]
|-
| 45–46 || [[Sergiu Samarian|Samarian, Sergiu]]
|-
| 38–39 || [[Aivars Gipslis|Gipslis, Aivars]]
|-
| 80 || [[Aivars Gipslis|Gipslis, Aivars]]
|-
| 90–91 || [[Aivars Gipslis|Gipslis, Aivars]]
|-
| 58–59 || [[Vlastimil Hort|Hort, Vlastimil]]
|-
| 66–69 || [[Mihail Judovič|Judovič, Mihail]]
|-
| 85–89 || [[Anatoly Karpov|Karpov, Anatoly]]
|-
| 43–44 || [[Viktor Korchnoi|Korchnoi, Viktor]]
|-
| 47–49 || [[Viktor Korchnoi|Korchnoi, Viktor]]
|-
| 15–19 || [[Alexander Kotov|Kotov, Alexander]]
|-
| 33–34 || [[Bent Larsen|Larsen, Bent]]
|-
| 30 || [[Aleksandar Matanović|Matanović, Aleksandar]]
|-
| 35–36 || [[Aleksandar Matanović|Matanović, Aleksandar]]
|-
| 30 || [[Dragan Ugrinović|Ugrinović, Dragan]]
|-
| 35–36 || [[Dragan Ugrinović|Ugrinović, Dragan]]
|-
| 25 || [[Milan Matulović|Matulović, Milan]]
|-
| 25 || [[Zdenko Krnić|Krnić, Zdenko]]
|-
| 06–09 || [[Nikolay Minev|Minev, Nikolay]]
|-
| 37–38 || [[Nikolay Minev|Minev, Nikolay]]
|-
| 40–42 || [[Bruno Parma|Parma, Bruno]]
|-
| 26–29 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 96–97 || [[Vasily Smyslov|Smyslov, Vasily]]
|-
| 10–14 || [[Alexey Suetin|Suetin, Alexey]]
|-
| 20–24 || [[Mark Taimanov|Taimanov, Mark]]
|-
| 81–84 || [[Wolfgang Uhlmann|Uhlmann, Wolfgang]]
|-
| 92–93 || [[Wolfgang Uhlmann|Uhlmann, Wolfgang]]
|-
|} <!-- end of Volume D -->
|
{| class="wikitable sortable"
|+ Volume E (1978)
! Code !! Author
|-
| 00–05 || [[Yuri Averbakh|Averbakh, Yuri]]
|-
| 00–05 || [[Yakov Neishtadt|Neishtadt, Yakov]]
|-
| 32–37 || [[Vladimir Bagirov|Bagirov, Vladimir]]
|-
| 67–69 || [[Isaac Boleslavsky|Boleslavsky, Isaac]]
|-
| 67–69 || [[Vladimir Lepeshkin|Lepeshkin, Vladimir]]
|-
| 27–29 || [[Mikhail Botvinnik|Botvinnik, Mikhail]]
|-
| 47–49 || [[Mikhail Botvinnik|Botvinnik, Mikhail]]
|-
| 27–29 || [[Lev Abramov|Abramov, Lev]]
|-
| 47–49 || [[Lev Abramov|Abramov, Lev]]
|-
| 97–99 || [[Robert Byrne (chess player)|Byrne, Robert]]
|-
| 97–99 || [[Edmar Mednis|Mednis, Edmar]]
|-
| 90–92 || [[Max Euwe|Euwe, Max]]
|-
| 46 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 56–59 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 10–11 || [[Aivars Gipslis|Gipslis, Aivars]]
|-
| 20–23 || [[Aivars Gipslis|Gipslis, Aivars]]
|-
| 95–96 || [[Vlastimil Hort]]
|-
| 54–55 || [[Borislav Ivkov|Ivkov, Borislav]]
|-
| 52 || [[Mihal Judovič|Judovič, Mihail]]
|-
| 83–84 || [[Anatoly Karpov|Karpov, Anatoly]]
|-
| 83–84 || [[Yuri Razuvayev|Razuvayev, Yuri]]
|-
| 43 || [[Alexander Kotov|Kotov, Alexander]]
|-
| 50–51 || [[Alexander Kotov|Kotov, Alexander]]
|-
| 06–07 || [[Zdenko Krnić|Krnić, Zdenko]]
|-
| 93–94 || [[Zdenko Krnić|Krnić, Zdenko]]
|-
| 06–07 || [[Srđan Cvetković|Cvetković, Srđan]]
|-
| 93–94 || [[Srđan Cvetković|Cvetković, Srđan]]
|-
| 85–86 || [[Bent Larsen|Larsen, Bent]]
|-
| 87–89 || [[Andor Lilienthal|Lilienthal, Andor]]
|-
| 87–89 || [[Tibor Flórián (chess player)|Florian, Tibor]]
|-
| 08–09 || [[Aleksandar Matanović|Matanović, Aleksandar]]
|-
| 15–19 || [[Aleksandar Matanović|Matanović, Aleksandar]]
|-
| 08–09 || [[Dragan Ugrinović|Ugrinović, Dragan]]
|-
| 15–19 || [[Dragan Ugrinović|Ugrinović, Dragan]]
|-
| 70–72 || [[Nikolay Minev|Minev, Nikolay]]
|-
| 76–79 || [[Nikolay Minev|Minev, Nikolay]]
|-
| 24–26 || [[Bruno Parma|Parma, Bruno]]
|-
| 53 || [[Bruno Parma|Parma, Bruno]]
|-
| 14 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 73–75 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 80–82 || [[Yuri Razuvayev|Razuvayev, Yuri]]
|-
| 12–13 || [[Alexey Suetin|Suetin, Alexey]]
|-
| 30–31 || [[Mark Taimanov|Taimanov, Mark]]
|-
| 40–45 || [[Mark Taimanov|Taimanov, Mark]]
|-
| 60–63 || [[Wolfgang Uhlmann|Uhlmann, Wolfgang]]
|-
| 38–39 || [[Wolfgang Unzicker|Unzicker, Wolfgang]]
|-
| 64–66 || [[Robert Wade (chess player)|Wade, Robert]]
|-
|} <!-- end of Volume E -->

|} <!-- end of meta-table -->

==Second edition==
The second edition was published in the following years:
* Volume A: 1996
* Volume B: 1984
* Volume C: 1981
* Volume D: 1987
* Volume E: 1991

{| class="wikitable sortable"
|+ Volume B (1984)
! Code !! Author
|-
| 04–05 || [[Vladimir Bagirov|Bagirov, Vladimir]]
|-
| 18–19 || [[Vladimir Bagirov|Bagirov, Vladimir]]
|-
| 13–14 || [[Mikhail Botvinnik|Botvinnik, Mikhail]]
|-
| 13–14 || [[Lev Abramov|Abramov, Lev]]
|-
| 10 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 12 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 15 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 17 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 36–39 || [[Miroslav Filip|Filip, Miroslav]]
|-
| 70–79 || [[Efim Geller|Geller, Efim]]
|-
| 95–99 || [[Aivars Gipslis|Gipslis, Aivars]]
|-
| 20–21 || [[Eduard Gufeld|Gufeld, Eduard]]
|-
| 23–26 || [[Eduard Gufeld|Gufeld, Eduard]]
|-
| 02–03 || [[Vlastimil Hort|Hort, Vlastimil]]
|-
| 80–85 || [[Garry Kasparov|Kasparov, Garry]]
|-
| 30–31 || [[Viktor Korchnoi|Korchnoi, Viktor]]
|-
| 34–35 || [[Viktor Korchnoi|Korchnoi, Viktor]]
|-
| 28–29 || [[Zdenko Krnić|Krnić, Zdenko]]
|-
| 87 || [[Zdenko Krnić|Krnić, Zdenko]]
|-
| 28–29 || [[Srđan Cvetković|Cvetković, Srđan]]
|-
| 00–01 || [[Bent Larsen|Larsen, Bent]]
|-
| 16 || [[Bent Larsen|Larsen, Bent]]
|-
| 60–69 || [[Aleksandar Matanović|Matanović, Aleksandar]]
|-
| 60–69 || [[Dragan Ugrinović|Ugrinović, Dragan]]
|-
| 06 || [[Nikolay Minev|Minev, Nikolay]]
|-
| 11 || [[Nikolay Minev|Minev, Nikolay]]
|-
| 57 || [[John Nunn|Nunn, John]]
|-
| 88–89 || [[John Nunn|Nunn, John]]
|-
| 07–09 || [[Bruno Parma|Parma, Bruno]]
|-
| 44 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 50–53 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 86 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 90–94 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 96 || [[Lev Polugaevsky|Polugaevsky, Lev]]
|-
| 27 || [[Alexey Suetin|Suetin, Alexey]]
|-
| 54–56 || [[Alexey Suetin|Suetin, Alexey]]
|-
| 58–59 || [[Alexey Suetin|Suetin, Alexey]]
|-
| 22 || [[Evgeny Sveshnikov|Sveshnikov, Evgeny]]
|-
| 33 || [[Evgeny Sveshnikov|Sveshnikov, Evgeny]]
|-
| 40–43 || [[Mark Taimanov|Taimanov, Mark]]
|-
| 45–49 || [[Mark Taimanov|Taimanov, Mark]]
|-
| 32 || [[Wolfgang Uhlmann|Uhlmann, Wolfgang]]
|}

==Third edition==
The third edition was published in the following years:
* Volume A: 1999
* Volume B: 1997 
* Volume C: 1997 
* Volume D: 1998 
* Volume E: 1998

==Fourth edition==
The fourth edition was published in the following years:
* Volume A: 2001
* Volume B: 2002  
* Volume C: 2000
* Volume D: 2004 
* Volume E: 2008

==Fifth edition==
The fifth edition was published in the following years:
* Volume C: 2006
* Volume B part 1 [ECO codes: B00–B49]: 2020
* Volume B part 2 [ECO codes: B50-B99]: 2021

==See also==
* [[Chess annotation symbols]] – ''ECO'' uses symbols instead of text
* [[Chess Informant]]
* [[List of chess books]]
* [[List of chess openings]] – for all ''ECO'' codes
* [[Opening book]]

==References==
{{Reflist}}

'''Bibliography'''
* {{Cite book
 | last1=Matanović | first1=Aleksandar | author-link1=Aleksandar Matanović
 | last2=Molorović | first2=Milivoje | last3=Božić | first3=Aleksandar
 | title=Classification of Chess Openings | publisher=Chess Informant
 | year=1971
}}
* {{cite book
 | author1=Abramov, Lev
 | author-link2=Vladimir Bagirov| author2=Bagirov, Vladimir| author-link3=Mikhail Botvinnik| author3=Botvinnik, Mikhail| author4=Cvetkovic, Srdan| author-link5=Miroslav Filip| author5=Filip, Miroslav| author-link6=Efim Geller| author6=Geller, Efim| author-link7=Aivars Gipslis| author7=Gipslis, Aivars| author-link8=Eduard Gufeld| author8=Gufeld, Eduard| author-link9=Vlastimil Hort| author9=Hort, Vlastimil| author-link10=Garry Kasparov| author10=Kasparov, Garry| author-link11=Viktor Korchnoi| author11=Korchnoi, Viktor| author12=Krnic, Zdenko| author-link13=Bent Larsen| author13=Larsen, Bent| author-link14=Aleksandar Matanović| author14=Matanović, Aleksandar| author-link15=Nikolay Minev| author15=Minev, Nikolay| author-link16=John Nunn| author16=Nunn, John| author-link17=Bruno Parma| author17=Parma, Bruno| author-link18=Lev Polugaevsky| author18=Polugaevsky, Lev| author-link19=Alexey Suetin| author19=Suetin, Alexey| author-link20=Evgeny Sveshnikov| author20=Sveshnikov, Evgeny| author-link21=Mark Taimanov| author21=Taimanov, Mark| author22=Ugrinovic, Dragan| author-link23=Wolfgang Uhlmann| author23=Uhlmann, Wolfgang
 | year=1984
 | title=Encyclopedia of Chess Openings, volume B
 | edition=2nd | location=[[Belgrade]] | publisher=[[Chess Informant]]
 | isbn=0-7134-3716-2}}
* {{cite book
 |last1=Hooper
 |first1=David 
 |author-link1=David Vincent Hooper
 |last2=Whyld
 |first2=Kenneth
 |author-link2=Kenneth Whyld
 |title=[[The Oxford Companion to Chess]]
 |publisher=[[Oxford University Press]]
 |edition=2nd
 |year=1996
 |orig-year=First pub. 1992
 |contribution=Encyclopedia of Chess Openings
 |page=123
 |isbn=0-19-280049-3 }}

==External links==
* {{cite web
 | url=http://sahovski.com
 | title=Chess Informant}} Publisher's site
* {{cite web
 | url=http://www.chessarch.com/library/0000_eco/index.shtml
 | title=Openings
 | publisher=Chess Archaeology}} ''ECO'' codes with names

{{Chess|state=collapsed}}

[[Category:Chess openings|*Encyclopedia of Chess Openings]]
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[[Category:Chess in Yugoslavia]]
[[Category:Chess in Serbia]]
[[Category:20th-century encyclopedias]]