The Modern Defense (also known as the Robatsch Defence after Karl Robatsch) is a hypermodern

chess opening A chess opening or simply an opening is the initial stage of a chess game. It usually consists of established theory; the other phases are the middlegame and the endgame. Many opening sequences have standard names such as the "Sicilian Defens ...

in which Black allows White to occupy the with pawns on d4 and e4, then proceeds to attack and undermine this "ideal" center without attempting to occupy it. The opening has been most notably used by British grandmasters Nigel Davies and

Colin McNab Colin Anderson McNab (born 3 February 1961) is a Scottish chess player. He is Scotland's second player to be awarded the title of Grandmaster (GM), fulfilling its requirements in 1992 just after Paul Motwani. After achieving his three norms ...

. The Modern Defense is closely related to the

Pirc Defence The Pirc Defence (pronounced ) is a chess opening characterised by the response of Black to 1.e4 with 1...d6 and 2...Nf6, followed by ...g6 and ...Bg7, while allowing White to establish a with pawns on d4 and e4. It is named after the Slovenian ...

, the primary difference being that in the Modern, Black delays developing the knight to f6. The delay of ...Nf6 attacking White's pawn on e4 gives White the option of blunting the g7-bishop with c2–c3. There are numerous transpositional possibilities between the two openings. The ''

Encyclopaedia of Chess Openings The ''Encyclopaedia of Chess Openings'' () is a reference work describing the state of opening theory in chess, originally published in five volumes from 1974 to 1979 by the Serbian company Šahovski Informator (Chess Informant). It is current ...

'' (''ECO'') classifies the Modern Defense as code B06, while codes B07 to B09 are assigned to the Pirc. The tenth edition of ''

Modern Chess Openings ''Modern Chess Openings'' (usually called ) is a reference book on chess openings, first published in 1911 by the British players Richard Clewin Griffith (1872–1955) and John Herbert White (1880–1920). The fifteenth edition was published in ...

'' (1965) grouped the Pirc and Robatsch together as the "Pirc–Robatsch Defense".

2.d4

Main line: 2.d4 Bg7

White's strongest response to the Modern Defense is 2.d4, to which Black typically responds 2...Bg7. The main continuations are: * 3. Nc3 d6 4. f4 c6 5. Nf3 Bg4 (the Standard Line, ''ECO'' B06) * 3. c4 (''ECO'' A40) d6 4. Nc3 Nc6 5. Be3 e5 6. d5 Nce7 (7.g4 will be answered by 7...f5 8.gxf5 gxf5 9.Qh5+ Ng6 10.exf5 Qh4 11.Qxh4 Nxh4 12.Nb5 Kd8) Other possibilities include: * 3.Bc4 (Bishop Attack) * 3.Bd2 (Westermann Gambit) * 3.Bd3 (Wind Gambit) * 3.f4 (Three Pawns Attack) * 3.g3 * 3.Nf3

Fischer's 3.h4!?

Bobby Fischer Robert James Fischer (March 9, 1943January 17, 2008) was an American chess grandmaster and the eleventh World Chess Champion. A chess prodigy, he won his first of a record eight US Championships at the age of 14. In 1964, he won with an 11� ...

suggested the move 3.h4!? as an unorthodox try against 1...g6 2.d4 Bg7, in his annotation to a game against

Pal Benko Pál C. Benkő ( hu, Benkő Pál; July 15, 1928 – August 26, 2019) was a Hungarian-American chess player, author, and composer of endgame studies and chess problems. Early life Benko was born on July 15, 1928 in Amiens, France, where his ...

. (Fischer played 3.Nc3 in the actual game.) The idea is to pry open Black's by h4–h5 followed by hxg6, as ...gxh5 would greatly weaken the cover to Black's king.

Averbakh System

The ''Modern Defense, Averbakh System'' (''ECO'' A42) can be reached by the lines: * 1.e4 g6 2.d4 Bg7 3.c4 d6 4.Nc3 (diagram) * 1.d4 g6 2.c4 Bg7 3.Nc3 d6 4.e4 (diagram) Possible moves for Black at this point include 4...Nf6, 4...Nc6, 4...e5, and 4...Nd7. The move 4...Nf6 leads to a position of the

King's Indian Defence The King's Indian Defence is a common chess opening. It is defined by the following moves: :1. d4 Nf6 :2. c4 g6 Black intends to follow up with 3...Bg7 and 4...d6 (the Grünfeld Defence arises when Black plays 3...d5 instead, and is cons ...

, where White has options 5.Nf3, 5.f3, 5.Be2, 5.f4, and so on.

Unusual White responses

The flexibility and toughness of the Modern Defense have provoked some very aggressive responses by White, including the crudely named

Monkey's Bum The Monkey's Bum is a variation of the Modern Defense, a chess opening. Although it may also be loosely defined as any approach against the Modern Defense involving an early Bc4 and Qf3, threatening "Scholar's mate", it is strictly defined by the ...

, a typical sequence being 1.e4 g6 2.Bc4 Bg7 3.Qf3. (A more refined version is the Monkey's Bum Deferred, where White plays Bc4 and Qf3 only after developing the .)

Unusual Black responses

Other unusual openings can be reached after 1.e4 g6. The

Hippopotamus Defence The Hippopotamus Defence refers to various irregular chess openings in which Black moves a number of pawns to the sixth , often developing pieces to the seventh rank, and does not move any pawns to the fifth rank in the opening. As an , it can also ...

is one such system. Another is the Norwegian Defence (also known as the North Sea Defence) which begins 1.e4 g6 2.d4 Nf6 3.e5 Nh5. (If White plays 4.g4, Black retreats the knight with 4...Ng7. On 4.Be2, Black can retreat the knight or

gambit A gambit (from Italian , the act of tripping someone with the leg to make them fall) is a chess opening in which a player sacrifices with the aim of achieving a subsequent advantage. The word '' gambit'' is also sometimes used to describe sim ...

a pawn with 4...d6!? If White plays 3.Nc3 instead of 3.e5, Black can transpose to the Pirc Defence with 3...d6 or continue in unconventional fashion with 3...d5!?)

Transpositions

Transpositions are possible after 2.c4, for example a

Maróczy Bind In chess, the Maróczy Bind () is a term alternately used to refer to an opening or its associated pawn structure, named for the Hungarian grandmaster Géza Maróczy. When the Bind is discussed as an opening, it is defined as 1. e4 c5 2. Nf3 ...

results after 2...c5 3.Nf3 Bg7 (or Nc6) 4.d4 cxd4 5.Nxd4 and the Averbakh system is reached after 2...Bg7 3.d4 d6 4.Nc3. After 2.Nf3, Black can play 2...c5, transposing to the

Sicilian Defense The Sicilian Defence is a chess opening that begins with the following moves: :1. e4 c5 The Sicilian is the most popular and best-scoring response to White's first move 1.e4. Opening 1.d4 is a statistically more successful opening for White b ...

, or 2...Bg7. Following 2.Nc3, Black can transpose to a closed Sicilian with 2...c5 or play 2...Bg7.

Kavalek vs. Suttles

In the following game played at the Nice

Olympiad An olympiad ( el, Ὀλυμπιάς, ''Olympiás'') is a period of four years, particularly those associated with the ancient and modern Olympic Games. Although the ancient Olympics were established during Greece's Archaic Era, it was not until ...

in 1974, Canadian GM

Duncan Suttles Duncan Suttles (born 21 December 1945) is a Grandmaster of chess who was the strongest Canadian player between the eras of Abe Yanofsky and Kevin Spraggett. He is one of the few over-the-board grandmasters who also holds the title of Grandmas ...

, one of the Modern's leading exponents, defeats Czech-American GM

Lubomir Kavalek Lubomir (Lubosh) Kavalek ( cz, Lubomír Kaválek, August 9, 1943 – January 18, 2021) was a Czech-American chess player. He was awarded both the International Master and International Grandmaster titles by FIDE in 1965.Hooper & Whyld 1992, p. 19 ...

:
:1. e4 g6 2. d4 d6 3. Nf3 Bg7 4. Be2 Nf6 5. Nc3 (Pirc Defence by transposition) 5... a6 6. a4 0-0 7. 0-0 b6 8. Re1 Bb7 9. Bc4 e6 10. Bf4 Nbd7 11. Qd2 b5! (initiating a deep combination; Suttles later remarked that Kavalek has occupied the center and developed his pieces in the manner advocated by Fred Reinfeld, yet now stands worse) 12. axb5 axb5 13. Rxa8 Qxa8 14. Bxb5 Bxe4 15. Nxe4 Nxe4 16. Rxe4 Qxe4 17. Bxd7 Ra8 18. h4 Qb7! (despite his advantage, White is in trouble; note that his

bishop A bishop is an ordained clergy member who is entrusted with a position of authority and oversight in a religious institution. In Christianity, bishops are normally responsible for the governance of dioceses. The role or office of bishop is ca ...

on d7 is nearly trapped) 19. d5 e5 20. Bh6 Qxb2 21. h5 Ra1+ 22. Kh2 Qb1 23. Bxg7 Qh1+ 24. Kg3 Kxg7 25. Bh3 Qc1 26. h6+ Kf6 27. c4 Qxd2 28. Nxd2 Kg5 29. Ne4+ Kxh6 30. Bd7 f5 31. Nf6 Ra7 32. Bb5 g5 33. Ng8+ Kg7 34. Ne7 Kf6 35. Nc6 Ra3+ 36. Kh2 h5 37. Nb8 h4 38. Na6 g4 39. Nxc7 Ra2 40. Kg1 g3 41. fxg3 hxg3 42. Kf1 e4 0–1