"notrump has been made, a bid of five notrump asks for additional high card ""features"". A king or doubleton king-queen not already shown in response to four notrump counts as one feature; a guarded king-queen combination not already shown count as two features. The responses are: Byzantine Blackwood convention Byzantine Blackwood is a bidding in the game of bridge. Devised by Jack Marx, it is a complex version of the (by which a four notrump (4NT) asks about 's holdings). Its premise is that both aces and kings may safely be shown in response to a Blackwood-type 4NT enquiry; provided"
"usually proceeds 3.Nc3 Nf6. The main line runs 4.Bg5, first played by Howard Staunton against Bernhard Horwitz in London, 1846. After 4.Bg5, a common trap is 4...d5? 5.Bxf6 exf6 6.Qh5+ g6 7.Qxd5 Qxd5 8.Nxd5 when White has regained his pawn, and since his knight is attacking the pawns on both c7 and f6, will come out a pawn ahead. Instead, Black usually tries to develop quickly and fortify his kingside, giving back the pawn if necessary, with 4...Nc6 5.d5 (White can regain the pawn with 5.Bxf6 exf6 6.Nxe4, but after 6...Qe7, White has no good way to defend the knight."
"and preparing for d2–d4. Black's most common reply is , which usually leads to the Ruy Lopez (3.Bb5), Italian Game (3.Bc4), or Scotch Game (3.d4), though 3.Nc3 Nf6 (the Four Knights Game), often played in the late 19th to early 20th century, or, less commonly, 3...g6 or ...Bb4, (the Three Knights Game), are other possibilities. If Black instead maintains symmetry and counterattacks White's center with then the Petrov's Defense will usually result, though White can avoid the extensive theory of the Petrov by playing 3.Nc3 if he wishes. The Philidor Defence, (2...d6), largely fell out of use after World War"
"few independent variations. This form has never attracted serious interest in high-level play, though Alexander Alekhine defeated Efim Bogoljubow with it in one game of their second match, in 1934. The Old Benoni is sometimes called the Blackburne Defense, after Englishman Joseph Henry Blackburne, the first player known to have used it successfully. In the Czech Benoni, also known as the Hromadka Benoni, after Karel Hromádka, Black plays 1.d4 Nf6 2.c4 c5 3.d5 e5. The Czech Benoni is more than the Modern Benoni, but also more passive. The middlegames arising from this line are characterised by much manoeuvring; in most"
"c4 e5 3. dxe5 Ng4 4. Bf4 Nc6 5. Nf3 Bb4+ 6. Nbd2 Qe7 7. a3 Ngxe5 8. axb4?? Nd3# (final position at left). Note that the knight cannot be taken because the pawn on e2 is pinned to the white king by the black queen on e7. Another notorious example is the so-called ""Blackburne Shilling Gambit"" (named after the 19th century English player Joseph Henry Blackburne, supposedly because he used it to win shillings from amateurs). It goes: 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nd4?! 4. Nxe5!? Qg5! 5. Nxf7?? Qxg2 6. Rf1 Qxe4+ 7. Be2 Nf3#"
"San Francisco convention The San Francisco convention (sometimes called the Warren convention after an otherwise-unknown American bridge player with that surname) is a slam seeking convention in the game of contract bridge. It was devised in the 1930s, but soon became obsolete. The convention is of the type where one partner bids four notrump as an artificial inquiry, and the other partner shows high cards (aces and kings) using an agreed set of codified responses. (The Blackwood convention and its variants have since the 1930s been the best-known example of this type.) In the Blackwood convention family, aces (and in"
"plays ...g6; alternatively, Black can play Qa5 and e5 to challenge White's centre, or expand on the with b5. A common deviation by Black in recent practice is 1.e4 d6 2.d4 Nf6 3.Nc3 e5. This has been tried by many GMs over the years, including Zurab Azmaiparashvili and Christian Bauer. White's 4.dxe5 is known to be equal, and play normally continues 4...dxe5 5.Qxd8+ Kxd8 6.Bc4 Be6 7.Bxe6 fxe6. Instead, White normally transposes to the Philidor Defence with 4.Nf3. An unusual but quite reasonable deviation for White is 1.e4 d6 2.d4 Nf6 3.f3. At the 1989 Barcelona World Cup event, former"
"by Black against any opening move from White, the corresponding move is playable by White as well. Black has many reasonable responses, such as 1...e5, 1...d5, 1...c5, 1...Nf6, and 1...g6. The most famous use of this opening was in the third game in the Deep Blue versus Garry Kasparov match in 1997. Kasparov believed that the computer would play the opening poorly if it had to rely on its own skills rather than on its opening book. The game was drawn. It had been previously used by David Levy in a prize match against Cray Blitz, where White won. Garry"
"including the Grand Prix Attack against the Sicilian Defense (1.e4 c5 2.Nc3 Nc6 3.f4), the Indian Opening (1.e4 e5 2.d3), and the Hanham Variation of the French Defense (1.e4 e6 2.d3), often referred to today as the King's Indian Attack. In this game from the Sixth American Chess Congress (at New York in 1889), Hanham (playing Black) uses his eponymous variation to defeat Joseph Henry Blackburne, one of the world's leading players: 1.e4 e5 2.Nf3 d6 3.Bc4 Be7 4.Nc3 c6 5.d4 Nd7 6.O-O Ngf6 7.Qe2 O-O 8.Be3 Qc7 reaching the typical setup of the Hanham Variation of Philidor's Defense. 9.Bb3"
"common move. The line 4.dxc6? Nxc6, described by Emms as ""a miserly pawn grab"", gives Black too much central control and development. Furthermore, after 4.dxc6 Black can play 4...e5, the Ross Gambit, which after 5.cxb7 Bxb7 resembles a reversed Danish Gambit. Most common after 3...c6 is 4.d4 cxd5, transposing to the Panov–Botvinnik Attack of the Caro–Kann Defence. 3...e6!? is the sharp Icelandic Gambit or Palme Gambit, invented by Icelandic masters who looked for an alternative to the more common 3...c6. Black sacrifices a pawn to achieve rapid development. The most critical line in this double-edged variation is thought to be"
"of his wide open and highly tactical style of play. His large black beard and aggressive style earned him the nickname of ""der Schwarze Tod"" (""the Black Death"", based on the plague of the same name) after his performance in the 1873 Vienna tournament. In 1881, according to one retrospective rating calculation, he was the second most successful player in the world. He was especially strong at endgames and had a great combinative ability which enabled him to win many brilliancy prizes, but he will be best remembered for his popular simultaneous and blindfold displays which captured the imagination of"
"(the Adams Attack, named after Weaver Adams), which was used several times by Bobby Fischer. In the Dragon Variation, Black fianchettoes a bishop on the h8–a1 diagonal. It was named by Fyodor Dus-Chotimirsky in 1901, who noticed a resemblance between Black's kingside pawn structure (pawns on d6, e7, f7, g6 and h7) and the stars of the Draco constellation. White's most dangerous try against the Dragon is the Yugoslav Attack, characterised by 6.Be3 Bg7 7.f3 0-0 8.Qd2 Nc6, when 9.0-0-0, 9.Bc4 and 9.g4 are White's most common moves. This variation leads to extremely sharp play and is ferociously complicated, since"
"Garry Kasparov used it to great effect against Anatoly Karpov in their 1985 World Championship match. Kasparov played 4.Nf3 six times, scoring three wins and three draws. Today as White, this is a favourite weapon of GM Alexei Barsov and former Women's Champion Nona Gaprindashvili. White develops the knight to a natural square and waits to see Black's reply. 4...d5 transposes to the Ragozin Defence of the Queen's Gambit Declined and 4...b6 5.Bg5 Bb7 transposes to the Nimzo/Queen's Indian hybrid line, so 4...c5 is the most common move that stays within Nimzo-Indian territory. Now 5.e3 transposes to the Rubinstein System,"
"adopt the Dilworth. In the Howell Attack (""ECO"" C81), 9.Qe2, White aims for play against d5 after Rd1. The game usually continues 9...Be7 10.Rd1 followed by 10...Nc5 or 10...0-0. Keres played this line several times in the late 1940s, and it is sometimes named after him. Karpov's move, 9.Nbd2, limits Black's options. In the 1978 Karpov–Korchnoi World Chess Championship match, following 9.Nbd2 Nc5 10.c3 d4 (10...Be7 is an old move that remains popular) Karpov introduced the surprising 11.Ng5, a move suggested by his trainer, Igor Zaitsev. If Black takes the knight with 11...Qxg5 White regains the material with 12.Qf3. This"
"possible. Black also seems to get a good game with 4...g6, and 4...Bb4+ has been played successfully as well. Postponing recapture of the queen pawn is a standard idea in the Scandinavian Defense (1.e4 d5 2.exd5 Nf6), but 3.Nf3 is less commonly played in the Center Game. Black can safely transpose to the Scotch Game, Petrov's Defense or the Philidor Defense, or play a line recommended by Alexander Alekhine, 3...Bc5 4.Nxd4 Nf6 and now 5.e5 would be met with 5...Qe7. Similar ideas are possible after 3.Bc4, which is also uncommon. The Halasz Gambit (3.f4?!) is another rare try. Although the"
"this is nowadays a common tactic, it was a relatively new idea at the time. Despite this anti-computer tactic, the game was drawn. ""May 7"". In this game Kasparov played the Caro–Kann Defence. Kasparov got into time trouble late in the game. The sub-optimal moves he played in a hurry may have cost him the victory. ""May 10"". In this game, the King's Indian Attack opening was played. As in the previous game, Deep Blue played a brilliant endgame that secured a draw, when it was looking as if Kasparov would win. If White plays 50.g8=Q then Black can force"
"in the center with 3...e5, or with ...e6 and ...d5. The opening has some distinct variations but it is highly transpositional, and may transpose to the King's Indian Defense, Nimzo–Indian Defense, Bogo–Indian Defense, Chigorin Defense, Ragozin System, Catalan Opening, and English Opening. The most common move, preventing 3...e5. Black usually responds with 3...e6, although 3...d6, intending a kind of Old Indian Defense, is also possible. After 3...e6, White can play 4.Nc3 Bb4 (transposing to the Nimzo–Indian Defense); 4.a3, when Black can either play 4...d5 (reaching a kind of Queen's Gambit Declined or Ragozin System), or 4...d6 preparing 5...e5 or even"
"in the 1840s, and the earliest game with it was probably played in 1843. The first game with the gambit accepted may be Meek vs Morphy, New York 1857. Carl Theodor Göring introduced it into master play in 1872, but while Göring's name is most often associated with the one-pawn gambit (5.Nxc3) Göring invariably used the double-pawn gambit with 5.Bc4. The gambit has been played by Ljubomir Ljubojević, David Bronstein, Frank Marshall, and Jonathan Penrose. In casual games Alexander Alekhine often transposed to it via the move order 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Nxc3, when ...Nc6 for Black and"
"to the slow movements of infantry advocated by Philidor (this fact is also confirmed by Witthalm). Only in his writings, he is closer to Philidor, whose ideas were prevailing at the time. From this perspective, it is probably not a coincidence that the variant of the King's Gambit named after him (1.e4 e5 2.f4 exf4 3.Nf3 g5 4.h4 g4 5.Ng5, the so-called Allgaier's Gambit) is a particularly sharp opening. After 5... h6, in fact, White must sacrifice the knight with 6.Nxf7, leading to a very tactical game (the author's analysis on this opening line is contained in the fourth edition"
"these games began as a King's Indian, with Black only later playing ...c5 and ...b5. Possibly the first to use the now-standard move order 1.d4 Nf6 2.c4 c5 3.d5 b5 was Thorvaldsson–Vaitonis, Munich Olympiad 1936. In many countries, particularly in the Eastern Bloc, the opening is known as the Volga Gambit. This name is derived from the Volga River after an article about 3...b5 by B. Argunow written in Kuibyshev (Samara since 1991), Russia, that was published in the second 1946 issue of the magazine ""Shakhmaty v SSSR"". Beginning in the late 1960s, this opening idea was also promoted by"
"Defence) and 6...Be7, once the most common line. 6...Nc6?! is inferior as it is favourably met by 7.c5!, after which White plans on seizing the e5-square by advancing the b-pawn to b5, or by exchanging the black knight on c6 after Bb5. The Tartakower or Fantasy Variation, 1.e4 c6 2.d4 d5 3.f3, somewhat resembles the Blackmar–Diemer Gambit. 3...e6 is probably the most solid response, preparing to exploit the dark squares via ...c5, though 3...g6 has been tried by Yasser Seirawan. GM Lars Schandorff and GM Sam Shankland both prefer 3...dxe4 4.fxe4 e5 5.Nf3 Bg4 6.Bc4 Nd7 7.0-0 Ngf6 8.c3 Bd6"
"to strongly favour White until a seminal game (Taimanov-Najdorf 1953) where Black introduced the maneuver Rf8-f7, Bg7-f8, Rf7-g7. When the chain arises in the Ruy Lopez, play is much slower with tempo being of little value and featuring piece maneuvering by both sides, Black focusing on the c7-c6 break and White often trying to play on the kingside with the f2-f4 break. Openings: Primary: French. Other: Nimzowitsch Defence. Character: Closed/semi-open but sharp game. Themes for White: kingside mating attack, f2-f4-f5 break. Themes for Black: Exchanging the hemmed-in QB, c7-c5 and f7-f6 breaks. Due to White's kingside space advantage and development"
"Nf6 3. b3 d5 4. Bb2 c5 5. e3 Nc6 6. a3 a6 7. Bd3 Bd6 8. Qe2 0-0 9. g4 Nxg4? Imprudently allowing White to attack Black's king along the g-file. 10. Qg2 Nf6 11. h4 h6 12. h5 Kh8 13. 0-0-0 Ne8 14. Rdg1 Rg8 15. Bh7!! f6 (15...Kxh7 16.Qg6+!! fxg6 17.hxg6+ Kh8 18.Rxh6#) 16. Bxg8 Kxg8 17. Qg6 Kh8 18. Ng5! hxg5 19. fxg5 Ne7 20. gxf6!! Nxg6 21. hxg6+ Kg8 22. Rh8+! Kxh8 23. f7 1–0 There is no defense against mate. If 23...Qh4 (stopping the threatened 24.Rh1+), 24.fxe8(Q)+ Bf8 25.Qxf8#. Francis J. Wellmuth calls this"
"in the early 1890s. The main line Englund Gambit (2...Nc6, 3...Qe7) was introduced by Kārlis Bētiņš (1867–1943), who also established the Latvian Gambit. The Swedish player Fritz Carl Anton Englund (1871–1933) sponsored a thematic tournament in which all games had to begin with the position after 4.Qd5; the 1.d4 e5 gambit complex was later named after him. The Blackburne–Hartlaub Gambit, 2...d6, was Charlick's original idea to avoid the closed openings, aiming for compensation for a pawn after 3.exd6 Bxd6. A sample continuation is 4.Nf3 Nf6 5.Bg5 h6 6.Bh4, when White remains a pawn up with some advantage. White can also"
"of this central breakthrough include Ojanen–Keres, Estonia–Finland match, Helsinki 1960 and Korchnoi–Tal, USSR championship, Yerevan 1962. The half-open e-file gives Black a certain degree of influence over the kingside. A rook on e8 puts pressure on White's e-pawn and restrains it from advancing. Tactics involving ...Nxe4 are not uncommon—the games Averbakh–Tal, USSR championship, Riga 1958, and Uhlmann–Fischer, Interzonal, Palma de Mallorca 1970, are well-known examples. Black can initiate further kingside activity by playing ...Nd7-e5 followed by ...g7-g5. The pawn move prevents White from driving away the knight with f2-f4, and sets up the possibility of Black bringing a knight on"
"...d5), or b4 (the latter is most often seen if White plays c4 before castling). Play often runs 2.g3 Nf6 3.Bg2 e6 4.Nf3 (4.Nh3!? is also possible, intending Nf4–d3 to control the e5-square if Black plays the Stonewall Variation) Be7 5.0-0 0-0 6.c4 and now Black chooses between 6...d5 (the characteristic move of the Stonewall), 6...d6, the Ilyin–Zhenevsky System (less popular today), or Alekhine's move 6...Ne4!? retaining the option of moving the d-pawn either one or two squares. The opening's attacking potential is shown in the Polish Immortal, in which Miguel Najdorf, using the Stonewall Variation, sacrificed all of his"
"level, giving White chances to seize a middlegame initiative. In recent years it has also been used against Black's kingside fianchetto pawn structure. A variation of East Indian Defence, after 1.d4 Nf6 2.Nf3 g6 3.Bg5, is often also called Torre Attack. After 3...Bg7, White usually plays 4.Nbd2 but can also play 4.c3. After 4.Nbd2, common lines include 4...0-0 5.c3 and 4...d5 5.e3 0-0. Loek Van Wely–Peter Leko, 1996 1.d4 Nf6 2.Nf3 g6 3.Bg5 Bg7 4.Nbd2 0-0 5.c3 d6 6.e4 c5 7.dxc5 dxc5 8.Bc4 Nc6 9.0-0 Qc7 10.Qe2 h6 11.Bh4 Nh5 12.Rfe1 Ne5 13.Nxe5 Bxe5 14.g3 Bh8 15.f4 Ng7 16.Qf3 Be6"
"Defence, and he often played what is now known as the Petrosian System: 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 6.Be2 e5 7.d5. This variation closes the center early in the game. One of the tactical ideas for White is to play Bg5, pinning Black's knight to his queen. Black can respond by either moving his queen (usually ...Qe8) or by playing ...h6, though the latter move weakens Black's kingside pawn structure. Two of Black's responses to the Petrosian Variation were developed by grandmasters Paul Keres and Leonid Stein. The Keres Variation arises after 7...Nbd7 8.Bg5 h6"
"was played successfully by Joseph Blackburne on at least one occasion, but is thought to be unsound (after 3.dxc6), and is almost never seen in master-level play. After 2...Qxd5, the most commonly played move is 3.Nc3 because it attacks the queen with gain of tempo. Against 3.Nc3, Black has a few choices. This is considered the ""classical"" line, and is currently the most popular option. White can choose from multiple setups. A common line is 4.d4 c6 (or 4...e5) 5.Nf3 Nf6 6.Bc4 Bf5 (6...Bg4 is a different option. Even though Black has shown that ...Bf5 can be an excellent move,"
"successfully is the game Mikhail Botvinnik versus Samuel Reshevsky from the 1948 World Chess Championship, which reached the position in the diagram after White's 24th move. Earlier in the game, Reshevsky was able to block White's attack by playing Nf6–e8 and f7–f5. Now, both White's bishops are reduced to defence, and White's queen is reduced to passivity at the a2-square to defend the pawns on a3 and c4. Without prospects for counterplay, White's game is strategically hopeless, and Black ultimately exchanged queens and won the endgame. The Rubinstein System (named after Akiba Rubinstein) is White's most common method of combating"
"Attack style with g3 and Bg2; this line was used by Fischer to crush Oscar Panno in a famous game (Fischer–Panno, Buenos Aires 1970). 3.c3 will transpose to lines of the Alapin Variation after 3...Nf6, or the French Defence after 3...d5 4.e5 Nc6 5.d4, though 4...d4 is stronger, as after 5.cxd4 cxd4 6.Qa4+ Nc6 7.Bb5 Bd7 8.Bxc6 Bxc6 9.Qxd4 Bxf3 is a strong pawn sacrifice, giving Black excellent compensation. 3.b3, intending Bb2, is a rare independent try, occasionally essayed by Heikki Westerinen in the 1970s. In ""Foxy Openings Vol. 30"", IM Danny Kopec suggests the move 3.Bd3 against any of"
"methods of declining the gambit—the classical variation (2...Bc5) and the Falkbeer Counter Gambit (2...d5)—are also popular. If Black accepts with , the two main continuations for White are: 3.Nf3 is the most common as it develops the knight and prevents 3...Qh4+. The Classical Variation arises after 3.Nf3 g5. Black defends his extra pawn, and threatens to kick the f3-knight with ...g4. The main continuations traditionally have been 4.h4 (the Paris Attack), and 4.Bc4. However, recently 4.Nc3 (the Quaade Gambit or Quaade Attack) has been recommended by Scottish grandmaster John Shaw as a less explored alternative to 4.h4 (he considers 4.Bc4"
"is the fork trick 4. Nxe5. Few games have been played with this line, but there is no clear refutation for Black. The name derives from White's play if Black captures the knight: 4...Nxe5 5. d4. The Berlin Defence, 3...Nf6, has long had a reputation for solidity and drawishness and is sometimes called ""the Berlin Wall"". The Berlin Defence was played in the late 19th century and early 20th century by Emanuel Lasker and others, who typically answered 4.0-0 with 4...d6 in the style of the Steinitz Variation. This approach ultimately fell out of favour, as had the old form"