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1969 Sarajevo - Kovacs vs Korchnoi
Every Move Explained

This game was played in 1969 between Viktor Korchnoi and Laszlo Kovacs during the international tournament at Sarajevo (then Yugoslavia, now Bosnia and Herzegovina). Kovacs had the White pieces, Korchnoi the Black.


Viktor Korchnoi (b.1931) had two chess careers. The first was as an elite grandmaster of the Soviet Union, where four times he won the prestigious national championship. The second was as a Soviet dissident, following his request for political asylum in July 1976, just after the Amsterdam international tournament, where he tied for first place.

So great was Korchnoi's impact on chess history that he was the only non-World Champion to merit a full chapter in Garry Kasparov's opus on his Great Predecessors. Korchnoi played title matches in 1978 and 1981 against arch-rival Anatoly Karpov, as well as an earlier candidates final match in 1974 to choose a challenger for then World Champion Bobby Fischer. That match became a de facto title match when Fischer declined to defend his title in 1975 and was forfeited.

Korchnoi's opponent in this game was Laszlo Kovacs (b.1938) a Hungarian player who earned the International Master (IM) title in 1965. The game was played at the Sarajevo international tournament, in the spring of 1969. Korchnoi finished first (+9-0=6), two points ahead of runnerup Milan Matulovic (YUG), who was a half point ahead of Svetozar Gligoric (YUG) and Wolfgang Uhlmann (DDR). Kovacs finished 15th (+2-8=5) in the field of 16 players.

A few months before the Sarajevo tournament Korchnoi had lost another candidates final match (+1-4=5) to Boris Spassky. Spassky went on to beat Tigran Petrosian for the World Championship, which he lost to Fischer in 1972.

Our notes are based on Korchnoi's in Viktor Korchnoi's Best Games, published in 1977. The book included 60 of Korchnoi's games, most of them annotated by Korchnoi.

Next move: 1.e4 • For more about White's first move, see our tutorial Chess Openings - Initial Position.


This game is the only encounter between Korchnoi and Kovacs recorded in modern chess databases, and was probably their only serious game together. It is unlikely that Korchnoi spent much time preparing for the game, but Kovacs would have had access to many games played by his famous opponent and undoubtedly had some idea what to expect in the opening.

The databases tell us that Kovacs had a preference for 1.e4, although he varied occasionally with 1.d4, 1.c4, and 1.Nf3. Playing White against the strongest player in the tournament, he chose his favorite initial move.

Next move: 1...e6 • For more about Black's responses to 1.e4, see our tutorial Chess Openings - King's Pawn Openings.


Like Emanuel Lasker, who was one of his own models, Korchnoi had a long chess career and never retired from active play. He transformed his playing style several times after starting to play in the 1940s, making it difficult to discuss an opening repertoire for a player who was active more than 60 years.

If we look at Korchnoi's games played before leaving the USSR in 1976, we see that his favorite responses to 1.e4 were 1...c5, 1...e6, and 1...e5, in that order, plus an occasional stab at variety with 1...Nf6 or 1...g6. Many strong players have had a preference for 1...c5 and/or 1...e5, but fewer have been adherents to 1...e6, the French Defense.

Unlike both 1...c5 and 1...e5, the French Defense is not played to prevent 2.d4. Its objective is to let White play that move, then counterattack immediately in the center with 2...d5. This strategy melded well with Korchnoi's characteristic strength, which was tenacious defense against an aggressive attack.

Also like Em.Lasker, Korchnoi was one of the great masters of defense. He had an impressive positive score against Mikhail Tal, the master of attack, and once remarked that he found Tal's style 'stereotyped'.

By playing 1...e6, which has the disadvantage of blocking Black's light squared Bishop on the very first move, Black announces the intention to play a strategic game. The lines will most likely remain closed throughout the opening and Black will seek to open them only after the initial development of both sides.

Next move: 2.d4

For more about White's play against the French Defense, see our tutorial Chess Openings - French Defense.


Against the French Defense, White plays 2.d4 in something like 90% of all games, perhaps more. The chief alternative is 2.d3, leading to an opening system called the King's Indian Reversed or King's Indian Attack. If then 2...d5, White closes the d-file with 3.Nd2, avoiding the exchange of Queens.

Kovacs also played 2.Qe2, a rarely played, eclectic move named the Chigorin Variation, after its original proponent, Mikhail Chigorin. Its purpose is to prevent 2...d5, because of 3.exd5, when the recapture by Black's e-Pawn is impossible.

In playing 2.d4, White thinks, 'You are letting me get a strong center with d4-e4 already on the second move? Thank you, I accept.'

Next move: 2...d5


If White plays 2.d4 in 90% of all games against the French Defense, then Black answers 2...d5 in 99% of those games. An alternative is 2...c5, which is a transposition into a little played sideline (1.e4 c5 2.d4 e6) of the Sicilian Defense. White can continue into a mainstream Sicilian with 3.Nf3, or head into Benoni-like variations (1.d4 c5 2.d5) with 3.d5.

Why is 2...d5 so popular? Black challenges the strong d4-e4 center immediately, places a Black Pawn in the center, and threatens 3...dxe4. The threat can't be ignored.

Next move: 3.exd5


Now White makes an important decision. The most popular moves in the diagrammed position are 3.Nc3 and 3.Nd2, developing a minor piece and defending the attacked e-Pawn. Somewhat less popular, but often favored by strategically minded players, is 3.e5, setting up a blockade of Black's center and attempting to shut in the light squared Bishop permanently.

Against 3.Nc3, Korchnoi's preferred move was 3...Bb4, although he occasionally used 3...Nf6. Against 3.Nd2, he preferred 3...c5, again with an occasional 3...Nf6, to keep his opponents guessing.

The move played, 3.exd5, is known as the Exchange Variation. It has a drawish reputation, confirmed by Korchnoi in his notes to the game: 'In making this move, White as it were announces that he is thinking only of a draw. The Exchange Variation, gives the Pawn structure a symmetrical character.' The most important aspect of the Pawn exchange is that it frees Black's problem piece, the light squared Bishop, allowing it to participate immediately in the action.

The Exchange Variation is used most frequently by players facing a stronger opponent, in situations where a draw is an acceptable result. In the current game, White was an IM facing a strong GM. A draw would have been more than acceptable.

Next move: 3...exd5


Just because a position is drawish doesn't mean it's an automatic draw. Korchnoi wrote

The open e-file foreshadows exchanges and a quick draw. This is what the authors of opening books assert. But there are few concrete variations to support this conclusion, and this is an important advantage in Black's favor. Modern opening theory helps the weak, strange as it may seem. One can learn and even understand a variation without having a high chess qualification, but true strength manifests itself in positions which have been studied little or not at all.

In playing 3.exd5, White, in contrast to the positions in fashionable variations, quickly moves away from the well-trodden paths. As early as the next few moves, he is forced to think for himself, and this, as is well known, is the most difficult.

Database statistics for the diagrammed position show a surprising result. Yes, the percentage of draws is high, approaching 50%. The surprise is with decisive games, where Black wins more often than White. In an open, symmetrical position we might expect White, who has the advantage of being on move, to score slightly more often than Black, but it is Black who scores more often.

The reason for this is undoubtedly because the players of the White pieces, who chose the exchange of Pawns on d5, are often weaker players than their opponents. As Korchnoi mentioned, 'true strength manifests itself itself in positions which have been studied little', whether those positions are drawish or not.

Next move: 4.Bd3


Now that White has embarked on a drawish course, how to continue? Because of the perfect symmetry, both players have the same choice of plans. Let's look at the strategic options that apply to both sides.

Pawns: The Pawn structure is not likely to change dramatically. Playing c2-c4 (or ...c5) is risky because it leaves the d-Pawn isolated. There are no other possibilities to position the Pawns for mutual exchange. • The blocked d-Pawns have a small influence on the Bishops. Each limits the movement of its own Queen's Bishop to some extent.

Minor pieces: Neither player has any obvious problem with the further development of the minor pieces. All eight pieces can be deployed immediately to a variety of squares. • The Knights all have a choice of two reasonable squares: Nc3/Nd2 (...Nc6/Nd7), and ditto for the King's Knights. Any Knight moving to its third rank is prone to a pin by an opposing Bishop. • The Bishops have a choice of several squares each, but a Bishop developed to the e-file will interfere with the action of its own major pieces on that file.

Castling: Castling O-O-O is not ruled out, but c2-c3 (...c6) might be needed to defend the d-Pawn. Since the move of the c-Pawn would loosen the castled position, castling O-O looks more likely.

Major pieces: The Rooks will come head-to-head on the e-file, while the best squares for the Queens are not yet decided.

It is possible that the game proceeds with a perfect symmetry rarely seen in chess: 4.Nf3 Nf6 5.Bd3 Bd6 6.O-O O-O 7.Bg5 Bg4 8.Nbd2 Nbd7 9.c3 c6 10.Qc2 Qc7 11.Rfe1 Rfe8.

After all of the preceding factors have been taken into account, three moves stand out: 4.Nf3, 4.Bf4, and the move played, 4.Bd3.

Next move: 4...Nc6


Black follows classic development of Knights before Bishops. Unless White decides to forfeit a tempo, the Knight will not be pinned by a Bishop.

Korchnoi judged 4...Nc6, 'Without doubt stronger than the routine 4...Bd6. White has to defend his d-Pawn.' He had played 4...Bd6 in two previous games, once meeting 5.Nf3, and once 5.c3, which was played by Tal.

Next move: 5.c3


White defends the d-Pawn in the most direct way. The move 5.c3 determines the following development of the White Queenside. The Knight will play to d2, but only after the Bishop has moved, to prevent it from being blocked.

Next move: 5...Bd6


The best square for the King's Bishop is now obvious. It can't go to b4, while on e7 it interferes, not only with the development of the Rooks to the e-file, but also with a possible development of the Knight to the same square. Once a move becomes obvious, it is often best to play it immediately. Let the opponent play one more move before making any further strategic decisions.

The Bishops on d3 (d6) prevent their opposite numbers from moving to f5 (f4). The move Bc1-f4 (...Bf5) now requires preparation.

Next move: 6.Qf3


As Korchnoi noted on this move,

There was not a great deal of choice. Apart from the move made, White could have played 6.Nf3. Nimzovitch used to recommend Black to answer 6.Nf3 by 6...Nge7, and 6.Ne2 by 6...Nf6.

Both 6.Qf3 and 6.Ne2 prepare a subsequent Bc1-f4. The Queen on f3 implies that White will continue Ng1-e2. The future of White's three undeveloped minor pieces have been determined : Bc1-f4, Ng1-e2, and Nb1-d2.

Black, however, still has choices to make. How should Black continue?

Next move: 6...Nce7


Already on the sixth move, Black makes a strong move that many players would never consider. We could easily call it a 'master move' or even a 'grandmaster move'. Korchnoi:

Black moves an already developed piece for the second time! The point here is not in a breaking of the symmetry -- it is worth trying to exploit the early development of White's Queen.

From e7, the Knight has no direct attack on White's Queen, so what is Korchnoi talking about? The reason behind 6.Qf3 was to play 7.Bf4. After 7...Bxf4 8.Qxf4, Black can play 8...Ng6, attacking the Queen.

What do you do when your opponent plays an unexpected move like 6...Nce7? A good reaction is to determine the reason for the move. In the diagrammed position, White should have done exactly that. Having found the reason, which is not hidden too deeply, he could then have looked for another plan for his own pieces. Of White's next move, Korchnoi noted

From the point of view of playing for simplification, this is consistent. But 7.Bg5 was stronger, hindering the development of Black's King's Knight. I was intending to reply 7...h6 8.Bh4 Be6, preparing Queenside castling.

He also noted that 7.Ne2 would have been better than the move in the game. It prepares a recapture by the Knight on f4; if 7...Nf6, then 8.Bg5 keeps Black guessing.

Next move: 7.Bf4


White continues with the plan prepared by 6.Qf3, which has one bright point. It exchanges the dark squared Bishops, thereby eliminating White's 'bad Bishop', restricted in its movements by the Pawns on c3 and d4.

Now Black could continue with 7...Bxf4 8.Qxf4 Ng6, but first makes an intermediate move.

Next move: 7...Nf6


Black completes development of the Kingside and prepares to castle O-O. The Knight move also threatens ...Bg4, developing the Bishop with a gain of tempo by an attack on the Queen. On this, Korchnoi noted

White wishes to prevent ...Bg4, but in doing so loses time. However, after the natural 8.Ne2 Bg4 his Queen would be somewhat uncomfortably placed. On 9.Qe3 it would be open to attack along the e-file, while on 9.Qg3 he would have to reckon with 9...Bxe2 10. Bxe2 Bxf4 11.Qxf4 O-O and ...Ng6, as well as with the sharper 10...Ne4.

Black isn't concerned if White avoids the Bishop exchange on f4 by exchanging first on d6. After the recapture 8...Qxd6, the Black Queen is developed to a comfortable square and Black takes the lead in overall development. The Queen would be well positioned to start creating mischief with ...Qb6.

Next move: 8.h3


White stops ...Bg4. The move 8.h3 also prepares a safety square for the Queen on h2. This might be useful if the threats from Black's minor pieces become too intense for the Queen.

In his note Korchnoi mentioned that White's move 'loses time'. A count of the undeveloped pieces adds up to five pieces for both sides, with Black to move. The advantage of the first move has passed from White to Black.

On 6...Nce7, Black lost a move by moving a piece for the second time. How is it possible that Black is now leading in development? Black may have spent one tempo repositioning the Knight, but White has spent two tempi on nondeveloping Pawn moves : 5.c3 and 8.h3.

Also worth noting is that Black's 6...Nce7 was for an aggressive purpose, attacking the enemy Queen. White's two Pawn moves were for defensive purposes.

Next move: 8...Bxf4


Black continues with the plan of swinging the Queen's Knight to the Kingside. The Bishop exchange will be followed by ...Ng6, attacking the White Queen.

Black had to play 8...Bxf4 before White played Ng1-e2, setting up a recapture on f4 by the Knight.

Next move: 9.Qxf4


To avoid losing a piece, White is forced to recapture the Bishop immediately. The King's Knight might now be developed on f3, a more active position than on e2.

Next move: 9...O-O


Black moves the King to safety and prepares to develop the Rook on the open e-file. The move ...Ng6, attacking the Queen, will still be available next move. Better to castle first, avoiding a Queen check on e3.

Next move: 10.Ne2


Why not develop the King's Knight on f3? This is, after all, the natural square for the piece.

One reason is strategical. White is still considering the future placement of the other Knight and decides that it would be equally well placed on f3. After White castles O-O, the King's Knight can take up an active post on f4 or g3, depending on circumstances.

Another reason is tactical. After 10.Nf3 Ng6, Black is simultaneously attacking the Queen and threatening a check on the e-file. White could avoid the worst with 11.Bxg6, but wants to keep the light squared Bishop. Otherwise its opposite number would rule the b1-h7 diagonal.

Next move: 10...Ng6


Four moves after playing 6...Nce7, Black carries out the plan initiated with that move. Not only does 10...Ng6, attack the Queen, it also opens the e-file for Black's major pieces.

It is worth noting how careful Black has been to keep the e-file unobstructed. Neither Bishop was developed there and the Knight that landed on e7 was only passing through on its way to a better post.

Where should White now retreat the Queen? Korchnoi rejected 11.Qf3 Nh4 and 11.Qc1 Qd6 12.O-O Nh5 13.Nd2 Nh4. He considered the best plan to be 11.Qg5 h6, and only now 12.Qc1, because pushing the h-Pawn has strengthened 13.Bxg6.

Next move: 11.Qh2


'Weak', according to Korchnoi, who noted that even 11.Bxg6 might have been better. The problem with 11.Qh2 is that it moves the Queen out of play. White, already lagging in development, will need a tempo to reactivate the piece later.

Why not play 11.Qg3 instead? After preparation by ...Re8, the Queen would be subject to further harrassment by ...Ne4. As for 11.Qd2, White needs to keep that square free for the development of the Knight.

Next move: 11...Re8


Black activates the first major piece, occupies the open e-file, and pins the Knight on e2. Given the right circumstances, Black might even be able to triple the major pieces on the e-file with ...Re6, ...Qe7, and ...Re8. As for White, since the Queen's Knight is still blocking its neighboring Rook and the Queen is out of action, White will have difficulty opposing any buildup on the e-file.

Surprisingly, Korchnoi thought that the similar plan with 11...Qe7 was 'more accurate' than 11...Re8. We'll see why in a few moves.

Next move: 12.O-O


White finally gets the King into safety, unpinning the Knight at the same time. Given a free hand, White will spend the next few moves activating both Knights.

On the other side of the board, Black needs to develop the last minor piece, but where? The only unattacked squares are d7 and e6. On e6, the Bishop blocks the important e-file, while on d7 the Bishop is doing nothing useful. Black finds another solution.

Next move: 12...Bf5


At first glance, 12...Bf5 looks like a blunder; the Bishop is under attack, but undefended. A second glance shows that the Bishop is under attack by the only piece defending the Knight on e2, and that Knight is attacked by the Rook on e8.

The Bishop move, then, is a complicated offer to exchange minor pieces. White might get an impressive piece on f5, but Black will get a Rook on its seventh rank.

Next move: 13.Bxf5


Korchnoi considered this 'probably the decisive mistake', and suggested 13.Nc1 instead. If then 13...Bxd3 14.Nxd3 Re2 15.Na3. This variation explains why Korchnoi considered 11...Qe7 more accurate than 11...Re8. If the Queen were on e7, Black would be able to play 14...Qe2, when 15.Na3 would leave the Knight on d3 unprotected.

Next move: 13...Rxe2


Black recaptures the piece, getting a Rook on the seventh rank at the same time. A 'Rook on the seventh' is often thought to be roughly equivalent to the advantage of a Pawn. The Rook simultaneously attacks targets on both the Queenside and Kingside.

In this game, as in many others, the Rook moving to the seventh rank vacates the first rank, giving the other Rook an available square on that file. That means doubled Rooks on an open file, another big positional advantage, might follow shortly.

The Rook on e2 has two immediate effects. The White b-Pawn is now under attack and the square d2 is no longer available to White's Knight. White risks falling further behind in development.

Next move: 14.b3


White moves the b-Pawn out of danger. Given the opportunity, the Knight will be developed to a3 and then via c2 to e3. This will close the e-file to Black's heavy pieces.

Next move: 14...Qe7


Black makes another multi-purpose move. The move 14...Qe7 doubles the heavy pieces on the e-file, opens the back rank for tripling with ...Re8, and prevents the White Knight from moving to a3. With all three of its developing squares unavailable, the Knight can't get into the game. Furthermore, the Knight's inability to move prevents the Queen's Rook from coming into the game.

Next move: 15.Bd3


Black's pressure is building and White needs to counteract it immediately. White wants to kick the Rook off the seventh rank, to e6, for example. This would allow the Knight to come into the game with Nb1-d2, followed by the Rook. This won't solve all of White's problems, but it would eliminate the most immediate.

Next move: 15...Rb2


Black decides that the Rook is safe on the seventh rank and moves it to the only square not attacked by a White piece. The Rook now has no squares to which it can safely move and may look vulnerable, but there are no pieces in a position to threaten it.

Meanwhile, White is still unable to develop the remaining Queenside pieces. The two squares available to the Knight remain controlled by Black.

Next move: 16.Qg3


The White Queen sees a path to the Rook on b2 and sets out to capture it. Perhaps Black has overlooked this.

White might have considered 16.c4. After 16...bxc4 17.bxc4 Rd8, Black has all pieces in the game and a target in the hanging Pawns on c4/d4. White has three pieces to be developed and a Queen out of play.

Next move: 16...Re8


Black brings the last undeveloped piece into play and doubles the heavy pieces on the open file. White still has three pieces to be developed : two Rooks and a Knight.

Next move: 17.Qg5


Did Korchnoi flinch here?

This looks strong, since White threatens to trap the venturesome Rook by Qc1. To be honest, I had overlooked this possibility. However, Black's position is extremely strong, and he finds an effective counter.

What makes Black's position 'extremely strong'? First, all of Black's pieces are developed. Second, one Rook has reached the seventh rank. Third, the other Rook forms a battery with the Queen on the e-file which Black can't oppose.

To contrast to Black's strengths, note White's weaknesses. Three pieces remain to be developed and the Queenside is completely blocked.

Was Black lucky to find 'an effective counter' to White's threat of Qg5-c1. Perhaps, but as the saying goes, 'Tactics flow from a superior position.' Put your pieces on the right squares and your game will play itself.

Next move: 17...Ne4


A Knight jumps to the center, attacking the Queen twice and forcing it to move. Black dares White to continue with the plan of trapping the Rook on b2. The key to Black's 17...Ne4 is the attack on the f-Pawn.

If now 18.Qxe7, then 18...Rxe7 heads for an endgame with Black retaining the big lead in development. If 18.Qxd5, Black can reply with the same move as in the game, but 18...Nxf2 looks even stronger; 19.Rxf2 loses to 19...Rxf2.

Next move: 18.Qc1


White attacks the Black Rook, which has no safe squares of retreat. Black's next move looks flashy, but it s forced. It must have been Black's intention on playing 17...Ne4. Korchnoi wrote

When my opponent made the move 3.exd5, it was not difficult to guess that he would be happy with half a point. But I must admit that the Hungarian master surprised me when, after trapping my Rook, he then offered a draw. After all, a quick glance at the position is sufficient to realize that any result is possible, only not a draw!

No grandmaster draws for Viktor Korchnoi!

Next move: 18...Rxf2


Black puts the attacked Rook to work by sacrificing it, desperado style. The sacrifice opens the White King's castled position.

How much material is Black sacrificing? Although the Rook leads the way, it will be swapped for the White Rook on f1. That Rook will be recaptured by the Knight, which will in turn be captured by the King. In return for the Knight, Black gets the Pawn on f2. The sacrifice then is a Knight for a Pawn.

As with all good sacrifices of material, the compensation is in the form of intangible positional advantages. After the dust has settled, the Black Queen and Rook will control the e-file, while the Queen having other useful squares on f6 and h4. The Black Knight can move closer to the enemy King on either f4 or h4. Meanwhile, White's pieces will be huddled uselessly in the Queenside corner.

For the next few moves, after the immediate piece trades, Black will effectively be playing with Queen, Rook, and Knight against Queen and Bishop. On top of that, White's King will be exposed to attack, especially on the dark squares.

Next move: 19.Rxf2


If White doesn't capture the invading Rook, the f-Pawn will simply have been lost. White would be a Pawn behind in material with the same positional disadvantages as on the previous moves. The move 19.Rxf2 and Black's response are both forced.

Next move: 19...Nxf2


Black continues with the real sacrifice, a Knight. This is the only move that justifies 18...Rxf2. Although White now accepts the Knight sacrifice, there was an alternative. Korchnoi noted

Better chances were offered by 20.Bxg6. If 20...fxg6 then 21.Kxf2 and Black's heavy pieces have no squares on which to intrude. Therefore Black would have to make the sacrifice 20...Nxh3+ 21.gxh3 hxg6 with excellent attacking chances.

In Korchnoi's last line, the straightforward 22.Nd2 fails to 22...Qg5+ 23.Kh1 Re2. A better continuation would be 22.Qd2 Qh4 23.Na3 Re4, but even here White can't cope with the Queen and Rook bearing down on the exposed King.

Next move: 20.Kxf2


White accepts the sacrificed Knight. Korchnoi noted an alternative

The other possibility was 20...Qh4+. I rejected this because of 21.g3 Qxh3 22.Bf1 Qh2+ 23.Bg2 and there is apparently no way for Black to include his Knight in the attack.

In the line Korchnoi rejected, the Pawn on g3 prevents the Knight from moving closer to the King by f4 or h4. The move 22...Qf5+, however, would have let Black continue the attack. It appears that 20...Qh4+ would also have given Black an excellent game.

Next move: 20...Qf6+


The Queen check 20...Qf6+ expands Black's avenues of attack. The Rook will still operate on the e-file, while the Queen attacks other squares. One result of the Queen move is to protect the f4-square, letting the Knight move there.

If now 21.Kg3, Black has 21...Re1, when the Rook can't be captured because of 21...Qf4+ checkmate. If then 22.Qd2, escaping the Rook's attack, Black continues 22...Rd1 23.Qe3 Rxd3.

Next move: 21.Kg1


Of the four moves to escape check, 21.Kg1 is the only move that gives White a playable game. Interposing with 21.Bf5 or 21.Qf4 just throws away material, while 21.Kg3 loses by the sequence explained in the previous note.

Next move: 21...Nf4


Black brings the last piece into the King hunt. The Knight attacks the Bishop on d3, which is undefended. Now Korchnoi gave two alternative defenses for White.

Protecting the Bishop by 22.Qd2 allows 22...Nxd3 23.Qxd3 Re1+ 24.Kh2 Qf4+ 25.Qg3 Rh1+, winning the Queen. This illustrates a common tactical trick in attacks against the King.

Protecting the piece by 22.Qf1 gives Black two continuations. After 22...Nxd3 23.Qxf6 (23.Qxd3 Re1+ is the same as the previous line) 23...gxf6, Korchnoi judged that White has drawing chances. He didn't say why, but Black's extra Pawn is part of a crippled Pawn majority on the Kingside that can't be straightened out. He suggested instead 22...Re3 23.Bb5 Rg3 as 'more energetic'. White carries on bravely with 24.Qe1 Rxg2+ 25.Kh1, but after 25...h6, Black's attack should win.

Next move: 22.Bf1


Protecting the Bishop doesn't work, so White moves it out of danger. The move 22.Bf1 also protects White's sensitive g-Pawn whose role is to provide shelter to the King.

One of White's problems is the weakness of the dark squares on the Kingside. The light squared Bishop can't guard any of the dark squares, while the two Pawns also protect only light colored squares.

Next move: 22...Re2


Black lands another powerful blow, bringing the Rook to its seventh rank. The Rook can't be taken with 23.Bxe2 because of 23...Nxe2+, forking the King and Queen.

The Rook move 22...Re2 has one drawback. Black's own first rank is left vulnerable to back rank mates, but White is nowhere near getting a major piece into a threatening position.

Next move: 23.Nd2


White finally develops the Queen's Knight! If the Knight can get to f3, it might be able to help with the defense of the King.

Next move: 23...Nxh3+


Black delivers one powerful blow after another. The Knight can't be taken with 24.gxh3, because 24...Qf2+ 25.Kh1 Qh2 is mate. The escape by 24.Kh1 loses to 24...Nf2+ 25.Kg1 Nd3 26.Qd1 Qf2+ 27.Kh1 (or 27.Kh2) 27...Re6.

Next move: 24.Kh2


White escapes the Knight check with the only move that doesn't lose by a forced sequence. Black, however, doesn't need a forced sequence to carry on with the attack.

The Knight is no longer attacked by the Pawn, which is now pinned by the Rook. It is, however, attacked by the King. White could now play 24...Qh6 to protect the Knight, but there is a better move.

Next move: 24...Nf4


Black's move threatens mate in various ways like 25...Qh4+ 26.Kg1 Nh3+. Covering h4 with 25.Nf3 loses to 25...Qh6+ 26. Kg1 Rxg2+ 27. Bxg2 Ne2+, when the Queen is attacked twice and defended only once.

Next move: 25.Kg3


White escapes the threatened mate by protecting h4 with the King. This also loses. At this point everything loses.

Next move: 25...Nd3


Black has a choice of winning moves. The move chosen, 25...Nd3, attacks the Queen and threatens mate in two moves starting 26...Qf4+. White resigns.

The conclusion to the game was a masterful attack stemming from a lead in development. The conclusion to this article is that you don't get a draw against a good player without earning it.

Next move: 0-1

For all games in the 'Every Move Explained' series, see
Improve Your Game.