Editing Irregular chess opening (section)

==Examples==

===Unusual first moves by White===
The vast majority of high-level chess games begin with either [[King's Pawn Game|1.e4]], [[Queen's Pawn Game|1.d4]], [[Zukertort Opening|1.Nf3]], or [[English Opening|1.c4]].<ref name=ChessBase>Randy Olson, [https://en.chessbase.com/post/popularity-of-chess-openings-over-time ''Popularity of chess openings over time''], ChessBase, 24 June 2014</ref> Also seen occasionally are [[King's Fianchetto Opening|1.g3]], [[Larsen's Opening|1.b3]], and [[Bird's Opening|1.f4]]. Other opening moves by White, along with a few non-[[transposition (chess)|transposing]] lines beginning 1.g3, are classified under the code "A00" by the ''[[Encyclopaedia of Chess Openings]]'' and described as "uncommon" or "irregular".<ref name="chessinformant">{{cite web | url=http://www.chessinformant.org/content/eco-codes.pdf | title=Encyclopaedia of Chess Openings Classification Code Index | publisher=chessinformant | access-date=6 July 2016 | archive-url=https://web.archive.org/web/20170829000056/http://www.chessinformant.org/content/eco-codes.pdf | archive-date=29 August 2017 | url-status=dead }}</ref><ref name="chessarch">{{cite web | url=http://www.chessarch.com/library/0000_eco/a00_a99.shtml | title=A00-A99 | publisher=chessarch | access-date=5 July 2016}}</ref> Although they are classified under a single code, these openings are unrelated to each other.

The openings classified as A00 are:
*1.[[b:Chess Opening Theory/1. a3|a3]] – [[Anderssen's Opening]]
*1.[[b:Chess Opening Theory/1. a4|a4]] – [[Ware Opening]]
*1.[[b:Chess Opening Theory/1. b4|b4]] – [[Sokolsky Opening]], also known as the Polish Opening or Orangutan Opening
*1.[[b:Chess Opening Theory/1. c3|c3]] – [[Saragossa Opening]]
*1.[[b:Chess Opening Theory/1. d3|d3]] – [[Mieses Opening]]
*1.[[b:Chess Opening Theory/1. e3|e3]] – [[Van 't Kruijs Opening]]
*1.[[b:Chess Opening Theory/1. f3|f3]] – [[Barnes Opening]], also known as Gedult's Opening
*1.[[b:Chess Opening Theory/1. g3|g3]] – [[King's Fianchetto Opening|King's Fianchetto Opening or Benko's Opening]]
*1.[[b:Chess Opening Theory/1. g4|g4]] – [[Grob's Attack]]
*1.[[b:Chess Opening Theory/1. h3|h3]] – [[Clemenz Opening]], or Basman's Attack
*1.[[b:Chess Opening Theory/1. h4|h4]] – [[Desprez Opening]], or Kadas Opening
*1.[[b:Chess Opening Theory/1. Na3|Na3]] – [[Durkin Opening]], also known as Durkin's Attack or the Sodium Attack
*1.[[b:Chess Opening Theory/1. Nc3|Nc3]] – [[Dunst Opening]]
*1.[[b:Chess Opening Theory/1. Nh3|Nh3]] – [[Amar Opening]], also known as the Paris Opening, Ammonia Opening, or Drunken Knight Opening

The [[Nimzowitsch-Larsen Attack]] (1.b3, ECO code A01) and [[Bird's Opening]] (1.f4, ECO codes A02–A03) have also been described as "irregular", particularly in older books.<ref name=Tartakower>[[Savielly Tartakower]] & Jules du Mont, [https://books.google.com/books?id=HW4WAwAAQBAJ&pg=PA651 ''500 Master Games of Chess''], Dover, 1952, p651</ref><ref name=Staunton />

===Unusual responses by Black===
Openings in which Black makes an unconventional response to 1.e4 are classified as B00 ([[King's Pawn Game]]).<ref name="chessinformant" /> Included in this code are:
*1.e4 a6 – [[St. George Defence]]
*1.e4 b6 – [[Owen's Defence]]
*1.e4 f6 – [[Barnes Defence]]
*1.e4 h6 – [[Carr Defence]]
*1.e4 Na6 – [[Lemming Defence]]
*1.e4 Nc6 – [[Nimzowitsch Defence]]
*1.e4 Nh6 – [[Adams Defence]]
*1.e4 a5 – [[Cornstalk Defence]]
*1.e4 b5 – O'Neill Gambit (loses pawn to 2. Bxb5)
*1.e4 f5 – [[Fred Defence]]
*1.e4 g5 – [[Borg Defence]]
*1.e4 h5 – [[Goldsmith Defence]]

Of these, 1...Nc6, 1...b6, 1...a6, and 1...g5 have received the most theoretical attention.<ref name=MCO>Nick de Firmian, [https://books.google.com/books?id=3xS_CAAAQBAJ&pg=PA543 ''Batsford's Modern Chess Openings''], 2014</ref> [[Tony Miles]] famously used 1...a6 to defeat [[Anatoly Karpov]].<ref name=Ottawa>Les Bunning, [https://news.google.com/newspapers?nid=2194&dat=19800628&id=MaMyAAAAIBAJ&sjid=g-4FAAAAIBAJ&pg=5891,3880942&hl=en Miles known for unorthodox style of play], Ottawa Citizen, 28 June 1980</ref>