Sicilian Defence, Najdorf Variation

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Classical Main line after 6...e6 7.f4

The main move. In the early days of the Najdorf 7.Qf3 was popular, but the reply 7...h6 did not allow White to obtain any advantage. Nowadays, White players almost universally respond with the move: 7. f4. White threatens 8.e5, but Black has several options:

• 7... Be7 8. Qf3 and now:
  • 8... Qc7 9. 0-0-0 Nbd7, this is called the old main line. At this point White usually responds with 10.g4 or 10.Bd3. After each of these moves there is a huge body of opening theory.
  • 8... h6 9. Bh4 g5. This is known as the Argentine/Goteborg Variation. It was first played in round 14 of 1955 Goteborg Interzonal simultaneously by Argentine players Panno, Pilnik and Najdorf who were facing the Soviet grandmasters Geller, Spassky and Keres. The games in question proceeded as follows: 10.fxg5 Nfd7 (Black aims to route a knight to e5, and then back it up by a knight at d7 or c6) 11.Nxe6!? (Efim Geller's discovery) 11...fxe6 12.Qh5+ Kf8 13.Bb5. Here Panno played 13...Ne5, while Pilnik and Najdorf chose 13...Kg7; however, all three Argentine players lost in very short order and the line was, for a while, considered refuted. In 1958 Bobby Fischer played 13...Rh7!, versus Svetozar Gligorić at the Portorož Interzonal, in a critical last-round game. According to modern opening theory, this position is a draw at best for White. A 10,000 node analysis by Leela Lc0 departs from this line with 11. Bg3. Black can route the knight as intended 11... Ne5. White blockades the h pawn 12. Qh5. Black can take the g5 pawn, leading to a knights exchange 12. ... Bxg5 13. Nf3 Nxf3 14. Qxf3
• 7... Qb6 one of the most popular choices at master level.
  • 8. Qd2 the extremely complicated Poisoned Pawn Variation: 8...Qxb2 9.Rb1 (9.Nb3 is the other less common option) 9...Qa3 and here White has played both 10.f5 and 10.e5. Both lead to extremely sharp play where slightest inaccuracy is fatal for either side. Since 2006, when it was played in several high level games, 10.e5 has become very popular. From the standpoint of the theory it is regarded as White's only attempt to play for a win against the Poisoned Pawn Variation since all other variations (and that includes the other pawn move, 10.f5) have been analysed to a draw with best play. An example is the game Vallejo Pons–Kasparov, Moscow 2004,[2] which was called "a model modern grandmaster draw!" by Kasparov himself in Revolution in the 70s (page 164).
  • 8. Nb3 White opts for a quiet game, but Black has nothing to worry about: 8...Be7 9.Qf3 Nbd7 10.0-0-0 Qc7 where we have reached a setup very similar to that of the old main line mentioned above. However, without the d4-knight White will find it very hard to organise an attack.
  • 8. a3 is a more challenging reply for White. It protects the pawn indirectly as 8...Qxb2?? is met by 9.Na4! winning the queen. Black usually plays 8...Nc6, although 8...Nbd7 is also playable. The 8.a3 line has been seen several times at the grandmaster level recently.
• 7... b5 the ultra-sharp Polugaevsky Variation.[3] Black ignores White's threat and expands on the queenside. 8.e5 dxe5 9.fxe5 Qc7 here White either plays 10.exf6 Qe5+ 11.Be2 Qxg5 or 10.Qe2 Nfd7 11.0-0-0 Bb7.
• 7... Qc7 championed by Garry Kasparov before he switched to playing 7...Qb6 exclusively.
• 7... Nbd7 popularised by Boris Gelfand.
• 7... Nc6?! is risky and of a dubious theoretical reputation due to the response: 8.e5!
• 7... h6!? the Poisoned Pawn Deferred. This variation is very popular at the moment. The line 8.Bh4 Qb6 9.a3 was played twice in the 2016 London Chess Classic (Caruana–Nakamura and Nakamura–Vachier-Lagrave[4]), though White won both games.

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Verbeterde List after 6...Nbd7 7.Bc4

Historically speaking, this was the usual reply until the mid-1960s, when the rejoinder 7.Bc4 put the move "out of business". Recently however, ideas have been found by some Dutch players who call this variation De Verbeterde List ("The Improved Stratagem"). The idea for Black is to postpone ...e6 in order to retain more dynamic options (for example, to play ...e7–e5 in one move). The idea was tested by Petrosian, Belov, and others, but received popular attention and developed rapidly after use by Dutch player Lody Kuling in 2007. The most important developments include:

• 7. f4 Qc7 8. Qf3:
  • 8... h6 9. Bh4 e5. A setup discovered by Lody Kuling. (This variation is covered by Ufuk Tuncer and Twan Burg in New In Chess, Yearbook 102.) The idea is to gain time over ...e6 by playing ...e7–e5 in one move. Later on it turned out that 9...g5! is even better.
  • 8... b5 is the Neo Verbeterde List. This is a new way to play the Verbeterde List. It includes fianchetting the bishop to b7. (The variation is covered by Ufuk Tuncer in New In Chess, Yearbook 101.)
• 7. Bc4 Qb6 This is a move introduced by Lenier Dominguez. The idea is to win a tempo by attacking b2, after which Black can finish his development beginning 8...e6. The last word on the line has not yet been given. The whole variation with 6...Nbd7 is covered in the book by Ľubomír Ftáčnik in the chapter "Blood Diamond".
• 7. f4/Qe2 g6 is Grischuk's Verbeterde List, another modern way to meet both 7.f4 and 7.Qe2. The idea is to castle kingside rapidly and then start to attack with ...b5–b4, while wasting no time with the e-pawn.

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English Attack: 6.Be3

This has become the modern main line. Since the early 1990s, the English Attack, 6.Be3 followed by f3, g4, Qd2 and 0-0-0 in some order, has become extremely popular and has been intensively analysed. Four lines are then usual for Black:

• The classical 6... e5:

If White plays 7.Nb3, then Black usually continues 7...Be6, trying to control the d5-square. The most common move is then 8.f3, allowing White to play Qd2 next move. If White had tried to play 8.Qd2, then Black could respond with 8...Ng4.

But if White plays 7.Nf3, then Black's main choices are 7...Be7 and 7...Qc7.

• Trying to transpose to the Scheveningen by playing 6... e6. White can either opt for the standard English Attack by playing 7.f3 or try the even sharper Hungarian Attack (also known as Perenyi Attack) by playing 7.g4.

• The knight move: 6... Ng4. White continues: 7.Bg5 h6 8.Bh4 g5 9.Bg3 Bg7, but the nature of this position is quite different from the ones arising after 6...e6 and 6...e5, so sometimes White tries to avoid the knight jump by playing 6.f3 instead of 6.Be3. However, aside from eliminating the option to play the Hungarian Attack mentioned above, it gives Black other possibilities such as 6...Qb6 and 6...b5.

• The Verbeterde List approach: 6... Nbd7. The idea of this move is to get into the English Attack while avoiding the Perenyi Attack. 7.g4 is less dangerous now because with 6...Nbd7 Black is more flexible as the bishop on c8 can attack g4 now and the knight on d7 can jump to interesting squares.

Introduced by Veniamin Sozin in the 1930s, this received little attention until Fischer regularly adopted it, and it was a frequent guest at the top level through the 1970s. White plays 6. Bc4 with the idea of playing against f7, so Black counters with 6...e6 7.Bb3 b5. The Sozin has become less popular because of 7...Nbd7 where Black intends to follow up with ...Nc5 later. It is possible to avoid the 7...Nbd7 option with 7.0-0, but this cuts out the aggressive possibility of castling long.

Because of the success of various players with these variations, White often plays 6. Be2 and goes for a quieter, more positional game, whereupon Black has the option of transposing into a Scheveningen Variation by playing 6...e6 or keeping the game in Najdorf lines by playing 6...e5. Another option is to play 6...Nbd7, in the spirit of The Verbeterde List; it is for this reason that this variation is called The Verbeterde List Unlimited.

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Amsterdam Variation: 6.f4

Some lines include:

• 6...e5 7.Nf3 Nbd7 8.a4 Be7 9.Bd3 0-0
• 6...Qc7 7.Bd3
• 6...e6 7.Be2

GM Daniel King recommends 6...g6 against the Amsterdam Variation, leading to a more defensive kingside pawn structure. The idea is to eventually counterattack on the g1–a7 diagonal with a move like ...Qb6, preventing White from castling.[5] An example line would be 6...g6 7.Nf3 Bg7 8.a4 Nc6 (note 8...Nc6 as opposed to the usual Najdorf ...Nbd7, as c6 is a more flexible square for the knight with a queen on b6) 9.Bd3 Qb6.

Introduced by Weaver Adams during the middle of the twentieth century, this odd-looking pawn move has mostly been used as a surprise weapon to combat the Najdorf. Should Black continue with 6...e5 anyway, White can respond with 7.Nde2 following up with g4 and Ng3, fighting for the weak light squares by playing g5. It is thus recommended that Black prevents g4 altogether with 7...h5.

Black can also employ a Scheveningen setup with 6...e6 followed by 7.g4 b5 8.Bg2 Bb7, forcing White to lose more time by defending the e4-pawn, since ...b4 is a threat. It was not until early 2008 that an answer to Black was finally found. After 9.0-0 b4, White has the positional sacrifice 10.Nd5!, which gives Black long-term weaknesses and an open e-file for White to play on. Since then, it has been popular on all levels of play.

Beside the main lines mentioned above White has other options: 6.f3, 6.g3, and 6.a4 are less common, but are also respected responses to the Najdorf. Moves such as 6.Bd3, 6.Qf3, 6.Rg1 (the Petronic Attack), 6.Nb3, 6.a3, 6.h4, 6.Qe2, and 6.Qd3 are rarely played, but are not so bad and may be used for surprise value. Other rare moves include 6.g4, 6.Nf3, 6.b3, and 6.Bd2.