Ruy Lopez

The Ruy Lopez is named after Ruy López de Segura, a 16th-century Spanish priest who systematically studied this and other openings in his 150-page chess book, Libro del Axedrez, written in 1561.^[1][4] Lopez advocated 3.Bb5 as superior to 3.Bc4, and was of the opinion that Black should play 2...d6 (the Philidor Defence) to avoid it. Although it bears his name, this particular opening was included in the Göttingen manuscript, which dates from c. 1490.^[5][6] The Ruy Lopez did not gain widespread popularity until the mid-19th century, when Finnish-Russian^{[7][further explanation needed]} theoretician Carl Jaenisch published a detailed article on 1.e4 e5 in the December 1847 issue of Le Palamède,^[8] the world’s first chess periodical. An abridged version appeared in the Chess Player's Chronicle in 1848,^[9] followed by a supplementary article in the same publication in 1849.^[10]

The Ruy Lopez has long been regarded as the most important opening among the Open Games at master level. Nearly every player has employed it at some point in their career, often with both colours.^[11] Due to the difficulty for Black in achieving equality, a common nickname for the opening is "The Spanish Torture".^[12][13]

The Morphy Defence (3...a6), the most popular reply, was played by Paul Morphy in the second game^[14] (a draw) and fourth game^[15] (a win for Morphy) of his 1858 match against Adolf Anderssen.^[16] The move gained widespread popularity and was subsequently named after him, although he was not its originator. Charles Henry Stanley played 3...a6 twice in his 1845 match, held in Morphy's hometown of New Orleans, against Eugène Rousseau for the United States Chess Championship. Stanley lost both games, although he won the match.^[17] Howard Staunton also mentioned 3...a6 in his Chess-Player's Handbook, first published in 1847.^[18] The first author to mention the move was Ercole del Rio, in his 1750 treatise Sopra il giuoco degli Scacchi, Osservazioni pratiche dell'anonimo Modenese (On the game of Chess, practical Observations by an anonymous Modenese).^[19] The late 19th century World Champion Wilhelm Steinitz did not approve of the move, writing in 1889 "on principle this ought to be disadvantageous as it drives the bishop where it wants to go". Steinitz's opinion did not prevail, however; 3...a6 is played in about two thirds of all games beginning with the Ruy Lopez.^[20]

The Berlin Defence (3...Nf6), the second most popular reply, has a reputation as a solid drawing weapon. It gained widespread popularity in the 2000s after Vladimir Kramnik demonstrated its viability in the 2000 Classical World Championship match against Garry Kasparov, successfully using it to draw in four of Kasparov's eight games with white.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

After 3...a6 4.Bxc6 dxc6 5.Nxe5 Qd4

At the most basic level, White's third move attacks the knight that defends the e5-pawn from the attack by the f3-knight. White's apparent threat to win Black's e-pawn with 4.Bxc6 dxc6 5.Nxe5 is illusory because Black can respond 5...Qd4 (diagram), forking the knight and e4-pawn, winning back the material with a good position.^[21] White's 3.Bb5 is still a good move, however; it develops a piece, prepares castling, and sets up a potential pin against Black's king. Since White's third move carries no immediate threat, Black can respond in a wide variety of ways.

An immediate choice for Black is whether to play 3...a6 or not. The point of the move is to force White to either retreat or exchange the bishop for Black's knight; thus the move "puts the question"^[21] to the white bishop, a traditional usage attributed to Aron Nimzowitsch.^[22][23] White must decide between exchanging the bishop for the knight with 4.Bxc6, or the more common retreat 4.Ba4. If 4.Ba4, Black will have the possibility of breaking a future pin on the queen knight by playing ...b5. White must take some care not to fall into the Noah's Ark Trap, in which Black traps White's king bishop on the b3-square with ...a6, ...b5, and ...c4 pawn advances on the queenside.

If Black decides not to play 3...a6, by far the most common alternative is the developing move 3...Nf6, the Berlin Defence. Less common alternatives are listed in the section Black's third move alternatives.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Morphy Defence: 3...a6

4.Bxc6 is the Exchange Variation.

After 4.Ba4, the most common response is 4...Nf6. A distant second is 4...d6, the Modern Steinitz Defence, which is generally regarded as stronger than its third-move equivalent, the Steinitz Defence.

• 4...d6 (Modern Steinitz Defence)
• 4...Bc5 (Classical Defence Deferred)
• 4...Nge7 (Cozio Defence Deferred)
• 4...g6 (Fianchetto Defence Deferred)
• 4...f5 (Jaenisch Gambit Deferred)
• 4...b5 5.Bb3 Na5 (Norwegian Defence)

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Morphy Defence after 4.Ba4 Nf6

After 4...Nf6, Morphy's choice in his games with 3...a6, Black appears to threaten the e4-pawn. However, White can eventually regain it and 5.0-0 is by far the most common response. The main alternative is 5.d3, the Anderssen Variation, which defends the pawn immediately.

• 5.d3 (Anderssen Variation)
• 5.Bxc6 (Bayreuth Variation)
• 5.Qe2 (Wormald Variation)
• 5.Nc3 (Tarrasch Variation)
• 5.d4 (Mackenzie Variation)

After 5.0-0, Black faces a major choice. The most common continuation is the solid 5...Be7, the Closed Defence, while 5...Nxe4, the Open Defence, and 5...b5, the Arkhangelsk Defence, represent important alternative systems.

• 5...Be7 (Closed Defence)
• 5...Nxe4 (Open Defence)
• 5...b5 (Arkhangelsk Defence)
• 5...Bc5 (Møller Defence)
• 5...d6 (Russian Defence)

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Closed Defence: 5.0-0 Be7

After 5...Be7, Black genuinely threatens to win a pawn with 6...b5 followed by 7...Nxe4, so White must respond. The usual continuation is 6.Re1, while the main alternative is 6.d3, the Martinez Variation, a modern line that has grown in popularity.

• 6.d3 (Martinez Variation)
• 6.Bxc6 (Steenwijker Variation)
• 6.Qe2 (Worrall Attack)
• 6.Nc3 (Morphy Attack)
• 6.d4 (Centre Attack)

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Closed Defence: 6.Re1

After 6.Re1, White threatens to win a pawn with 7.Bxc6 followed by 8.Nxe5. Black can defend the e5-pawn with 6...d6, the Averbakh Variation, but the far more popular response is 6...b5, chasing White's bishop away. After 7.Bb3, Black may choose 7...Bb7, the Trajković Variation, but far more common are 7...0-0, leading to the Marshall Attack and Anti-Marshall Systems, and 7...d6, which typically continues with 8.c3 (addressing Black's threat of 8...Na5, which would exchange the white bishop; 8.a4 is an interesting alternative^[24]). Following 8...0-0, possible continuations are 9.d4 (Yates Variation) or 9.d3 (Pilnik Variation), but 9.h3, preventing the pin 9...Bg4, is by far the most common move, reaching the main line of the Ruy Lopez.

• 6.Re1
  • 6...d6 (Averbakh Variation)
  • 6...b5 7.Bb3
    • 7...Bb7 (Trajković Variation)
    • 7...0-0 (Marshall Attack and Anti-Marshall Systems)
    • 7...d6 8.c3 0-0
      • 9.d4 (Yates Variation)
      • 9.d3 (Pilnik Variation)
      • 9.h3 (Main line)

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Modern line: 6.d3

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Modern line tabiya: 6.d3 b5 7.Bb3 d6 8.a3 0-0 9.Nc3

By playing 6.d3, often called the Martinez Variation,^[25] White steers clear of the Marshall Attack and any of the Anti-Marshall lines. White threatens 7.Bxc6 winning the e5-pawn leaving Black a choice of either 6...d6 or 6...b5. After 6...d6 the e5-pawn is firmly defended and Black threatens to trade off White's Ruy Lopez bishop with 7...b5 and 8...Na5. White normally continues with 7.c3, and after 8...0-0 White can choose between 9.Nbd2 or 9 Re1. More common is 6...b5 7.Bb3 d6 (7...0-0 is a viable alternative), after which White must address the threat of 8...Na5. Following 8.a3 (the alternatives 8.c3 0-0 and 8.a4 Bd7 are equally playable), Black typically continues with 8...0-0, though the immediate 8...Na5 is also feasible. After 9.Nc3, we arrive at a modern tabiya of the Ruy Lopez (second diagram). This position was first reached in a high-level encounter between Viswanathan Anand and Michael Adams at the Grenke Chess Classic in 2013.^[26]

This variation can transpose into 6.Re1 lines but with a potentially advantageous move order. For example, in the 8.a4 Anti-Marshall which can ensue after 6.Re1, one of the main lines is 8...Bb7 9.d3, which can also be reached by way of 6.d3 b5 7.Bb3 0-0 8.a4 Bb7 9.Re1. A perhaps more challenging response to the Anti-Marshall is 8...b4, after which White may wish to ambitiously play 9.a5 (preventing ...Na5) d6 10.d3 Be6!, where White cannot avoid the trade of bishops (the main moves being either 11.Bxe6 or 11.Nbd2 Bxb3). If Black elects not to exchange, however, we may see 11.Nbd2 Rb8 12.Nc4 where White may retain some pull in the position. On the other hand, to be considered is 6.d3 b5 7.Bb3 0-0 8.a4 b4 9.a5 d6 10.Nbd2 Be6 11.Nc4!, where White has avoided the exchange and can transpose directly to the Anti-Marshall line if desired by playing Re1 later. Play may also in some rare cases transpose to a traditional closed Spanish (with 7...d6) after something like 6.d3 d6 7.c3 0-0 8.Re1 b5 9.Bc2 Bb7 10.Nbd2 Re8 11.h3 Bf8 12.d4, reaching a reasonably well-trodden position in the Zaitsev system, though both players may deviate at many points in this line.

It is also possible to transpose to the Pilnik Variation after 6...b5 7.Bb3 d6 8.c3 0-0 and 9.Re1, thereby successfully avoiding the Marshall Attack (which the Pilnik Variation itself does not do). In general, if 6...b5 7.Bb3 d6 8.c3, positions could resemble a traditional closed Spanish such as the Zaitsev, Flohr, Smyslov, Karpov, Breyer, or Chigorin where White has played 10.d3 (or in the case of the Chigorin, 11.d3 with 10.Bc2 c5 included) instead of 10.d4 (in the case of the Chigorin, 11.d4) if White plays Re1 and h3. In every case, 10.d3 is far less popular than 10.d4 (again, 11.d4 for Chigorin), but is the only move besides d4 to ever be seriously considered. 10.d3 in those variations are often referred to as the 'quiet' variation of that variation (quiet Breyer, quiet Flohr, quiet Chigorin, etc). In the case of Flohr–Zaitsev-type setups, White may quickly push d3–d4 without h3 and lose a tempo compared to the traditional Zaitsev, but the move h3 is what would be lost, which is not so relevant with the bishop already committed to b7, so the only thing h3 provides is luft (an idea shared with the Pilnik).

6.d3 has gained wide popularity among the top players and has become a frequent alternative to the Ruy Lopez main line with 6.Re1.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Worrall Attack: 6.Qe2

In the Worrall Attack (ECO C86), White replaces 6.Re1 with 6.Qe2. The idea is that the queen will support the e-pawn, leaving the rook free to move to d1 to support the advance of the d-pawn, although there is not always time for this. Play normally continues 6...b5 7.Bb3 followed by 7...0-0 8.c3 and 8...d5 or 8...d6.

Paul Keres played the line several times. More recently, Sergei Tiviakov has played it, as has Nigel Short, who essayed it twice in his 1992 match against Anatoly Karpov and won both games.^[27][28]

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Morphy Attack: 6.Nc3

The Morphy Attack (ECO C84) is named after Paul Morphy, who introduced the idea in a 1859 blindfold simul.^[29] It is aggressive and may lead to a slight edge for White, but less than in 6.Re1 and 6.d3. Similar to those two moves, White's defence of the e4-pawn compels Black to drive away White's bishop with 6...b5 (6...d6 is also possible, but less popular). After 7.Bb3, Black can play 7...0-0 or 7...d6. Note that Marshall attack-style ideas of 7...0-0 and playing ...d5 next, sacrificing a pawn, make little sense when White's knight on c3 both controls d5 and means White has a more developed queenside, one of the upsides of the Marshall usually being White's underdeveloped queenside. The main line of 7...d6, 8.Nd5 Na5 9.Nxe7 Qxe7 10.d3 0-0, with Black eventually relinquishing White of the bishop pair with ...Nxb3, shows a common attacking idea in the Morphy Attack; Nd5. In the main line, 8...Nxd5? is wrong because 9.Bxd5! leaves White with a strong bishop on the outpost square d5, exerting a troublesome pin on the undefended c6-knight. After 7...0-0, 8.d3 transposes to one of the main lines of 6.d3, with 6...b5 7.Bb3 0-0 8.Nc3. Paul Keres and Boris Spassky have both played the line a few times throughout their careers (both playing it against one another once), and Siegbert Tarrasch played it three times in his 1911 match against Schlechter (scoring 1 win, 1 draw, 1 loss in that order), but it remains the least popular option for White on move 6.

6.Bxc6 is known as the Steenwijker Variation, Delayed Exchange Variation Deferred, or Exchange Variation Doubly Deferred (ECO C85). It loses a tempo compared to the Exchange Variation, though in compensation, the black knight on f6 and bishop on e7 are awkwardly placed. The knight on f6 prevents Black from supporting the e-pawn with ...f7–f6, and the bishop is somewhat passively posted on e7.

6.d4 is the Centre Attack^[30] or Centre Variation (ECO C84). It leads to sharp play. After 6...exd4 (6...Nxe4 and 6...b5 are viable alternatives) 7.Re1 b5 (7...0-0 8.e5 Ne8 is a playable alternative) White can play either 8.Bb3 or the sharp 8.e5. In case of the immediate 7.e5 Black takes advantage of the absence of the white rook from e1 and plays 7...Ne4 with the idea of 8...Nc5.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Averbakh Variation: 6.Re1 d6

In the Averbakh Variation (C87), named for Yuri Averbakh, Black defends the threatened e-pawn with 6...d6 instead of driving away the white bishop with the more common 6...b5. This defence shares some similarities with the Modern Steinitz Defence and Russian Defence as Black avoids the ...b5 advance that weakens the queenside. White can reply with either 7.Bxc6 bxc6 8.d4 or 7.c3 Bg4 (it is too late for Black to transpose into the more usual lines of the Closed Defence, because 7...b5 would allow 8.Bc2, saving White a tempo over the two-move sequence Bb3–c2 found in other variations). The pin temporarily prevents White from playing d2–d4. In response, White can either force d4 with 8.h3 Bh5 9.Bxc6 bxc6 10.d4, or postpone d4 for the time being and play 8.d3 followed by manoeuvering the queen knight to the kingside with Nbd2–f1–g3.

After 6.Re1 b5 7.Bb3, an alternative to 7...0-0 and 7...d6 is 7...Bb7. This is known as the Trajković Variation.^{[citation needed]} Black may sacrifice a pawn in the style of the Marshall Attack with 8.c3 d5 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 Nf4 (11...0-0 transposes to a line in the Marshall Attack). 8.d3 transposes to the Arkhangelsk Defence with 6...Bb7.

White may also avoid 9.h3, most often with 9.d4 or the quieter 9.d3.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Bogoljubow Variation: 9.d4 Bg4

After 9.d4, the most common continuation is 9...Bg4 (the Bogoljubow Variation). The pin of White's knight on f3 is troublesome. The variation takes its name from the game Capablanca–Bogoljubow, London 1922.^[31]

After 9...Bg4, White usually plays 10.Be3, reinforcing the pawn on d4. The main line continues 10...exd4 11.cxd4 Na5 12.Bc2 c5 13.h3 (13.d5?! allows 13...Nc4 with a tempo on the e3-bishop) Bh5. The main alternative is 10.d5, with the most common continuation being 10...Na5 11.Bc2 c6 12.h3 Bc8 13.dxc6 Qc7 14.Nbd2 Qxc6 15.Nf1.

The Yates Variation can also be reached via the 8.d4 Anti-Marshall move order: 7...0-0 8.d4 d6 9.c3.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Pilnik Variation: 9.d3

The Pilnik Variation, named for Hermann Pilnik, is also known as the Teichmann Variation from the game Teichmann–Schlechter, Karlsbad 1911.^[32] White plays 9.d3 intending to later advance to d4 under favourable circumstances. Although d2–d3–d4 appears to lose a tempo compared to d2–d4, White may be able to omit h3 regaining the tempo, especially if Black plays ...Bb7.

The Pilnik has seen a small resurgence in recent years, but that is mainly by transposition through 6.d3 (or 8.d3), which avoids the Marshall Attack. The line starting with 6.d3 leading to the Pilnik is 6.d3 b5 7.Bb3 d6 8.c3 0-0 9.Re1.

• 9.a4, after 9...b4 10.a5, transposes to a line in the 8.a4 Anti-Marshall that goes 8.a4 b4 9.a5 d6 10.c3.
• 9.a3 is the Suetin Variation.
• 9.Bc2 is the Lutikov Variation.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Main line: 6.Re1 b5 7.Bb3 d6 8.c3 0-0 9.h3

This is the traditional main line of the Closed Defence and is usually regarded as the main line of the Ruy Lopez as a whole. Thousands of top-level games have reached this position. With 8.c3, White prepares the central break d4 and plans the typical knight manoeuvre Nbd2–f1–g3, firmly reinforcing e4 while activating the bishops on open diagonals and directing both knights toward Black's kingside. Black, in turn, seeks to counter this plan by expanding on the queenside, challenging the centre, or increasing pressure on e4.

Black has several common moves, including 9...Na5 (Chigorin Variation), 9...Nb8 (Breyer Variation), 9...Bb7 (Zaitsev Variation), 9...Nd7 (Karpov Variation), 9...Be6 (Kholmov Variation), and 9...h6 (Smyslov Variation). For decades, the Chigorin Variation was Black's principal choice, but alternative lines rose to prominence in the second half of the twentieth century as players like Boris Spassky and Anatoly Karpov sought ways to avoid the necessity of repositioning Black's awkwardly placed knight.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Chigorin Variation: 9.h3 Na5 10.Bc2 c5 11.d4 Qc7

The Chigorin Variation was refined by Mikhail Chigorin around the turn of the 20th century and became the primary Black defence to the Ruy Lopez for more than fifty years. With 9...Na5 Black chases the white bishop from the a2–g8 diagonal and frees the c-pawn for queenside expansion. After 10.Bc2 c5 11.d4, the classical follow-up is 11...Qc7, reinforcing e5 and placing the queen on the c-file, which may later become open after ...cxd4. Other Black moves in this position are 11...Bb7 and 11...Nd7; the latter was adopted by Paul Keres a few times in the 1960s. The Chigorin Variation has declined in popularity because Black must spend time bringing the offside knight on a5 back into the game. 10...d5 is the Gajewski Gambit, sacrificing the e-pawn for open lines. This is less sound than 10...c5, but can be good in practical play.

The Chigorin is divided into four ECO classifications. In C96, Black or White deviate after 10.Bc2, and do not reach the classical main line position 10...c5 11.d4 Qc7. In C97, White proceeds from the diagram with 12.a4, 12.d5, 12.b4, or the main line 12.Nbd2 when Black responds with ...Be6, ...Rd8, ...Re8, ...Bb7, or ...Bd7. The C98 classification covers 12.Nbd2 Nc6, while C99 covers 12.Nbd2 cxd4 13.cxd4.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Breyer Variation: 9.h3 Nb8 10.d4 Nbd7

With 9...Nb8, Black frees the c-pawn and intends to route the knight to d7 where it supports e5. If White fortifies the centre with 10.d3, the opening is classified ECO code C94. The more common continuation, 10.d4, is ECO C95.

The Breyer Variation was recommended by Gyula Breyer as early as 1911,^[33] but there are no known game records in which Breyer employed this line. The Breyer Variation did not become popular until the 1960s when it was adopted by Boris Spassky and others. In particular, Spassky's back to back wins over Mikhail Tal at Tbilisi in 1965 did much to enhance its reputation, and Spassky had a career-plus score with the Breyer. The variation was the choice of many top level players as White has had trouble proving an advantage against it. Nowadays, however, this variation is considered too passive, and players seeking a draw with Black against 1.e4 often prefer to play the Berlin Defence (3...Nf6) or Petrov's Defence (2...Nf6) instead.

After 10.d4, the main line continues 10.d4 Nbd7 11.Nbd2 Bb7 12.Bc2 Re8 13.Nf1 Bf8. Black is threatening to win the e4-pawn via ...exd4 uncovering an attack on the pawn, so White plays 14.Ng3. Black generally plays 14...g6 to stop White's knight from going to f5. White then usually tries to attack the Black queenside via 15.a4. Black seeks counterplay in the centre via 15...c5. White can attack either the kingside or the queenside. This forces resolution of the centre via 16.d5. Black can exploit the weak squares on the queenside via 16...c4. White will try to attack on the kingside via 17.Bg5, moving forces to the kingside. Black will kick the bishop with 17...h6. The logical retreat is 18.Be3, which is met by 18...Nc5. White plays 19.Qd2, forcing 19...h5, the point of the manoeuver being to weaken Black's kingside.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Zaitsev Variation, main line: 9.h3 Bb7 10.d4 Re8 11.Nbd2 Bf8

The Zaitsev Variation (also called the Flohr–Zaitsev Variation) was advocated by Igor Zaitsev, who was one of Anatoly Karpov's trainers for many years. A Karpov favourite, the Zaitsev remains one of the most important variations of the Ruy Lopez. With 9...Bb7 Black prepares to put more pressure on e4 following 10.d4 Re8. One drawback of this line is that White can force a draw by repetition with 11.Ng5 Rf8 12.Nf3.

The main line continues with 11.Nbd2 Bf8. Here, White has 12.a4 and 12.a3 as the main moves, alongside 12.d5 and 12.Bc2. 12.Nf1? loses a pawn after 12...exd4 13.cxd4 Na5 14.Bc2 Nxe4, where White has insufficient compensation.

Along with the Breyer Variation, the Zaitsev Variation is one of the most common lines being played in the traditional main line of the Ruy Lopez. It has a high draw rate.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Karpov Variation: 9.h3 Nd7 10.d4 Bf6

Karpov tried 9...Nd7 several times in the 1990 World Championship match, but Kasparov achieved a significant advantage against it in the 18th game. It is solid but slightly passive. Confusingly, 9...Nd7 is also called the Chigorin Variation, so there are two Ruy Lopez variations with that name, but 9...Na5 is the move more commonly associated with Chigorin. This defence is also known as the Keres Variation, after Paul Keres.

With 9...Nd7, Black frees up f6 for the bishop, aiming for a setup with ...Bf6, ...Nd7–Nb6, and ...Bb7. Play continues with 10.d4 Bf6 11.a4 Bb7. Now, White continues with 12.Na3; in the Karpov Ruy Lopez the knight usually goes to Na3 instead of Nbd2–f1–g3 to put more pressure on Black's queenside, and it can also be transferred to c2, preventing Black's knight from moving to b4 and where it can move to e3 or b4 if the situation calls for it. The main line continues 12...exd4 13.cxd4 Re8 14.axb5 axb5 15.Bf4 Na5 16.Bc2 b4 17.Nb5 Bc6 18.Qd3 b3 19.Bb1 Qb8 20.Nc3, where White has a space advantage.

White can opt for 12.d5 instead of 12.Na3 for closed positions, where play continues 12...Ne7 13.axb5 axb5 14.Rxa8 Qxa8 15.Na3 Ba6 16.Nc2 Nc5 17.Nb4 and either 18.Nb4 or 18.Bc2.

The Kholmov Variation, 9...Be6, was popular in the 1980s but is now played less often at the master level. The main line runs 10.d4 Bxb3 11.axb3 (11.Qxb3 is another option) exd4 12.cxd4 d5 13.e5 Ne4 14.Nc3 f5 15.exf6 Bxf6 16.Nxe4 dxe4 17.Rxe4 Qd5 18.Rg4, when it has been shown that White's extra pawn is more valuable than Black's more active and harmonised pieces.

The Smyslov Variation (ECO C93) is a plan similar to that of the Zaitsev Variation. With 9...h6, Black prepares to play 10...Re8 and 11...Bf8 without fear of 10.Ng5. The loss of a tempo with 9...h6 gives White enough time to complete the Nbd2–f1–g3 manoeuver, and the pawn move can also weaken Black's kingside. The Zaitsev can be considered to be an improved Smyslov in which Black tries to save a tempo by omitting ...h6. Black sometimes plays ...h6 later in the Zaitsev, however.

Kasparov played the Smyslov Variation in a loss to the Deep Blue chess computer in Game 2 of their 1997 Man vs Machine match.^[34]

Svetozar Gligorić has been the most prolific C93 player.^[35]

• 9...Qd7 is another variation by Vasily Smyslov.
• 9...Re8 10.d4 transposes either into the Zaitsev Variation after 10...Bb7 or the Smyslov Variation after 10...h6.

Black may depart from the main line after 6.Re1 b5 7.Bb3 by castling with 7...0-0. Black then intends to meet 8.c3 with 8...d5, offering a pawn in exchange for active play against White’s king. To avoid this highly theoretical gambit, White often chooses one of the eighth-move alternatives (8.a4, 8.h3, 8.d4, or 8.d3), collectively known as the Anti-Marshall Systems, which aim to discourage Black from executing the ...d5 break. When White chooses 8.c3, Black may also transpose to the main line with 8...d6, a practical option for players who do not mind facing an Anti-Marshall variation but still prefer the main line to the Marshall Attack.

Marshall Attack

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h 7...0-0 8.c3 d5 a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Main line: 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 c6; in 1918 Marshall played 11...Nf6 instead.[36]

One of Black's more aggressive alternatives, the Marshall Attack is a gambit as 8...d5 sacrifices a pawn. The line beginning with 9.exd5 e4 is known as the Steiner Variation^[37], named after the American chess player Herman Steiner. The main line of the Marshall Attack begins with 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 c6 (Marshall's original moves, 11...Nf6, and 11...Bb7, are also playable). To the casual observer it might seem that Black has been careless and lost a pawn, but the sacrifice has also stripped off White's kingside defenders, given Black a lead in development, and rendered White's 8.c3 irrelevant. Black generally goes all-in with a massive kingside attack, which has been analysed to great depth (sometimes beyond move 30) with no definite conclusion as to the Marshall's soundness. It is a sharp opening system in which a great amount of theoretical knowledge is vital, and many White players, including Garry Kasparov, avoid it by playing one of the Anti-Marshall systems: 8.d3, 8.d4, 8.a4, or 8.h3 instead of 8.c3.^[38][39] In these lines, attempting to play similarly to the Marshall with 8...d5 allows White's knight on b1 to eventually develop to c3, while it is blocked from doing so by White's own pawn in the Marshall.

This gambit became famous when Frank James Marshall used it as a prepared variation against José Raúl Capablanca in 1918; nevertheless, Capablanca found a way through the complications and won.^[36][40] It is often said that Marshall had kept this gambit a secret for use against Capablanca since his defeat in their 1909 match.^[41] The most common counterclaim is that Marshall had used a similar approach in 1917, playing the Steiner Variation against Walter Frere.^[42] However, chess historian Edward Winter found no clear evidence of the date for the Frere game; several games between 1910 and 1918 where Marshall passed up opportunities to use the Marshall Attack against Capablanca; and a game by Carl Walbrodt from 1893^[43] that used the same line as in Frere vs Marshall.^[44]

The Marshall Attack has been adopted by top players including Boris Spassky, John Nunn, and Michael Adams. In the Classical World Chess Championship 2004, challenger Peter Leko used the Marshall to win an important game against World Champion Vladimir Kramnik.^[45] Currently, Armenian grandmaster Levon Aronian is one of the main advocates for the Marshall Attack.^[46]

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

8.a4 Anti-Marshall, main line: 8.a4 b4 9.d3 d6 10.a5 Be6

The 8.a4 Anti-Marshall is the most popular way for White to avoid the Marshall after 7...0-0. The main line is 8...b4 9.d3 d6 10.a5 Be6. After this, 11.Nbd2 and 11.Bxe6 are the best moves for White.

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

8.h3 Anti-Marshall, main line: 8.h3 Bb7 9.d3

8.h3 aims to transpose back into the main line with 8...d6 9.c3. The typical central break 8...d5 is less effective: 9.exd5 Nxd5 10.Nxe5 Nxe5 11.Rxe5 c6 (or 11...Bb7 12.d3, which transposes to 8.h3 Bb7 9.d3 d5 10.exd5 Nxd5 11.Nxe5 Nxe5 12.Rxe5) 12.Re1!; the c3-square is available to the knight, giving White a significant advantage.

The main continuation is 8...Bb7 9.d3, whereas 9.c3 is inaccurate because after 9...d5 10.exd5 Nxd5, White cannot continue with the Marshall-like 11.Nxe5? Nxe5 12.Rxe5 due to the strong move 12...Nf4.

After 8.h3 Bb7 9.d3, Black can play the solid 9...d6, posing the positional threat of 10...Na5. White should respond with 10.a3, 10.a4 or 10.c3 to create space for the light-squared bishop.

After 8.h3 Bb7 9.d3, Black can also play 9...d5 in typical Marshall Attack style. Following 10.exd5 Nxd5 11.Nxe5, Black targets White's light-squared bishop with 11...Nd4 (11...Nxe5 12.Rxe5 Qd6 is a viable alternative). With active piece play and a lead in development, Black gains sufficient compensation for White's extra pawn. This position was reached in game six of the 2016 World Championship match between Sergey Karjakin and Magnus Carlsen.^[47]