Friday, August 30, 2013

All the best everyone!

It's the big day tomorrow, guys!

I know some of you might be nervous, and some others may be intimidated by the difficulty of the playing field in your category. Nevertheless, my orders to every team and individual are the same. Give every game your best shot, and strive to win as many games as you can. For no matter how great the odds are, I will always maintain my trust in y'all that every one of you will your best, regardless of whatever position we get in the end.

All the best for tomorrow everyone! Ride on to Rulang, ride on to victory!


Sunday, August 25, 2013

The art of successful defence: Part 1

It comes to my mind that while you are busy learning how to attack, it is equally important that you know how to defend successfully against an attack. Even if you are the sort who has a to-hell-with-it attitude about your own position and prefers to launch all-out attacks (aka the Mihail Tal style), there will always be times when you have to defend your own base against an even more aggressive opponent, in order to stave off defeat.

Get your a**es back to base, they're gonna capture our flag before we capture theirs!

Steinitz, the first World Champion, was also the first player to perfect defensive technique. He introduced the art of positional play in the late 19th century, showing that it was superior to the all-out attacking style that was the norm at the time. Subsequently, his teachings were expounded by many other leading players of the early 20th century such as Siegbert Tarrasch and Emanuel Lasker, his successor as World Champion.

After the rise of the Hypermodern school, Nimzowitsch introduced several new concepts into defensive play. A notable one were the ideas of overprotection and prophylaxis, which we will discuss later on.

Today, chess literature tends to classify the art of defence into two categories: Active and passive defence. Passive defence refers to one where one makes direct responses to the enemy's attacks, but with no other ideas in mind. Active defense, on the other hand, is one where one responds to the enemy threats by making threats of his own.

Not surprisingly, active defense is considered to be more dangerous for the attacker, for should the attack fail, then the new threats set up by the defender will enable him to launch his own counterattack. Passive defence, on the other hand, is also possible but not as threatening-- if the attacker's assault fails, he still has a chance to regroup his forces for a fresh assault, assuming that he still has enough strength to do so.

The following are a few defensive techniques that you will encounter frequently in tournament play:

  • Defence by prohpylaxis: Setting up your position in such a way that it is difficult for the attacker to penetrate with his pieces.
  • Defense by repulsion: Through the usage of force to capture, exchange or eject enemy pieces that have found their way into the position. This may lead to Defence by Elimination:
  • Defence by elimination: Trading off important attacking pieces of the opponent helps to reduce the strength of his attack, and (if possible) simplify the position into a winning endgame.
  • Defence by overprotection: A subset of prophylactic defence, but a very strong one. The defender piles the protection of many pieces onto threatened squares, such that it is difficult for the attacker to overpower and seize these squares.
  • Defence by blockade: Blockading the opponent's pieces or pawns, thus closing off his avenues of attack.
  • Defence by king flight: Steinitz called this the "king's self-defense". The king leaves the castled position, usually to move over to the other wing where the fighting is not so hot. Similar to evacuating your house when it's on fire.
  • Defence by counterattack: When the attacker attacks on one wing, the defender launches a parallel attack on another wing. The most common representative of an active defense.
Today we will revise our foundations by looking at the 3 most basic forms of defence: Prophylaxis, repulsion and simplification.


Defence by prophylaxis

The idea of prophylaxis (Greek for "guarding" or "preventing beforehand") was first introduced by Aaron Nimzowitsch as part of the hypermodern theory. As its name suggests, a prophylactic move is one made to guard against a possible threat made by the opponent. Such moves are often aimed not just to improve one's position, but also to prevent the opponent from improving his.

One example of prophylaxis occurs in the Sicilian game after 1. e4 c5 2. Nf3 d6 3. d4 exd4 4. Nxd4 Nf6 5. Nf3. Now, if Black wants to prevent White from posting a piece on b5 (e.g. 6. Nb5 or 6. Bb5+, which can be problematic for Black), he can play the prophylactic move 5... a6, controlling the b5 square.

Another common form of prophylaxis takes place in the advance of the rook pawn, thus preventing an embarrassing back-rank mate.

As we can see, this art of "looking ahead" is very important if you are looking towards perfecting your defensive play; only by spotting your opponent's threats and making preventive moves against them can you ward off his tactical blows, and make your own position better in the process. It is this concept of prophylaxis that has bred many successful positional players such as Anatoly Karpov and Tigran Petrosian

In the two examples that follow up, put yourself in the position of the player whose turn it is to move. Try to identify what possible threats your opponent can make, and think of possible prophylactic moves to ward off these threats.

Example 1:

White to move after 1... Rc8
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Threat: 2... Nb4, and White cannot respond to the multiple threats against c2 and e4 at the same time

The best prevention against this will be 2. Ng3! (The knight was already on the maneuver Nb1-d2-f1-g3 anyways), and after 2... Nb4, 3. Bb1 address the multiple threats effectively. 2. a3 and 2. Bd2 are also possible but not as strong-- a3 forces White to waste tempo in the moving of pawns, while the dark-squared bishop is only a temporary defender of the b4 square (since it can be chased away easily).

Example 2:

Black to move after 1. f5
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Threat: 2. f6! cutting off the g7 bishop from the rest of the game

Best prevention will be 1...f6; although White is still slightly better after 2. Nd5, at least it is still better than 2. f6 Bh8, where Black is effectively a piece down.

Note that 1... Re8, giving the bishop the f8 square, is not so effective as much tempo will have to be spent to get the bishop back into the game.


Defence by repulsion

Despite all preventive effort, it is sometimes inevitable that enemy pieces may still find a way into your camp. When that happens, the most direct way to defend against their threats will be to repulse these pieces-- either by capturing, exchanging or chasing them away.

A simple example of forceful repulsion occurs after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4, after which White can try to eject Black's bishop by 4. a3. Black now has to choose between retreating the bishop with 4... Be7 (and wasting tempo), or capturing the knight with 4... Bxc3 (and giving up the bishop pair).

I can show you another example from one of my games played last semester:

Opponent - Checkerboard 5
Thomson CC Chess Challenge 2013
Position after 16. Qd6
With his last move my opponent's Queen invaded via Qa3-d6. Now to let her Majesty sit there with such impunity will be really brave and really rash indeed, for the Queen exerts a dominating influence over many of the squares within Black's position! It is thus obligatory for Black to find a way to eject the Queen from his position, which is done with precision:

16... Rad8! 17. f5

If 17. Qa3, then 17... Nxd4 also wins for Black

18. Nxe5!

Repulsing the invading Queen with a discovered attack, and winning a pawn in the process. I went on to win the game several moves later.


Defence by simplification

In the face of an aggressive attack the general rule for defenders is to trade off as many of the pieces as possible, especially the key pieces which the attacker relies on for his attack to succeed. Each time an exchange is made, a hostile piece of the attacker is removed, and the strength of his attack is drained by a certain degree. This makes the task of the defender a much easier one.

Similarly, when you are the one attacking the important rule is always NEVER to trade off your attacking pieces unless absolutely necessary (e.g. exchanging pieces to clear a square for your other pieces). The following example shows how a simple exchange can stem the flow of an attack:

Checkerboard 5 - Checkerboard 28
Black Knights Internal Tournament 2013, Round 9
Position after 20. Rd7
White's situation is critical-- his f1 bishop is pinned, the light-coloured squares around his camp are under enemy control, and the blockading rook on d7 is a shaky one that can be easily undermined. Black could have won easily with 20... Bb4+! after which 21. Qxb4 Rxd7 wins material and seizes control of the open d-file. Instead, Black played

20... Bh4?!

A hasty attempt to find a quick checkmate. White now forces the repulsion of the dark-squared bishop:

21. Bg3 Bxg3?

A second mistake, and one that violates the general rule that I have stated just now: When attacking, do not exchange your pieces unnecessarily! Trading the dark squared bishops only serves to make White's defensive task easier; he can continue to maintain his blockade on the 7th rank, and bring in his a1 rook to aid in the defence.

22. hxg3

White's troubles are not over yet (his pinned f1 bishop and light-squared weaknesses still exist), but at least he can find solace in the fact that his game is not totally lost.

In the next example, Black is up in material, but faces a difficult problem: His d1 rook is under attack, which is in turn guarding the e7 bishop that is also under attack! How is he going to solve the multiple threats to his position?

Black to move
If he tries 1... Be6??, then there follows 2. Qxd8+ Nxd8 3. Rxd8#. If he instead tries 1... Ne7, then 2. Qd6 Nf5 3. Qxd7+ Rxd7 4. Rc8+ also loses.


The best solution to this will be a drastic simplifying move:
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1... Qxd1! 2. Qxd1 Bg4!

With the threats to his position warded off, Black can now use his material advantage to win the game.

...

In Part 2, we will talk about a few more techniques used in defensive play

Sources:
http://www.wpcentral.com/world-of-tanks-e3
http://www.chess.com/article/view/simplify-to-victory
"Looking for Trouble: Recognizing and meeting threats in chess" by Dan Heisman

Friday, August 23, 2013

How to attack: Part 3

Ranks, files and diagonals in the attack against the castled king

In the attack against a particular focal point in the castled position, it is important that the attacker utilize as many pieces as he can to achieve his goal. In the case that there are open files or diagonals that lead the way into the enemy camp, however, the attacker's strength lies in the usage of his long range pieces-- namely the rooks, bishops and queen.

It's like playing an first-person shooter-- if you see your enemy charging towards you across an open corridor (which probably only easy AIs will do so), will you run back at him with a knife? Or will you rather mow him down with your SMG?

You'd do more damage throwing the knife butt at him
Every gamer I've known will choose the latter (unless he or she is so skilled at dodging bullets and running at the same time with a mouse and keyboard alone), simply because long-range weapons work better than short-ranged ones in an open battleground.

Similarly, in a chess game, long-range pieces are the ones who help to seize control of the open files or diagonals. They are the ones who will control the entire rank, file or diagonal from a distance, while the line is being cleared of enemy influence. Knights and pawns, on the other hand, can be used as supporting pieces (e.g. sacrificing a knight to clear a square and open a file) but never as the protagonists in such actions.

Today, we will consider the roles played by ranks, files and diagonals, and how they are involved in the attacker's plans to break into the opponent's castled position.


The open/semi-open files involved in the attack on the castled king

Of all the long range actions, the most commonly seen are operations involving open files. This is because it is easier to clear an open file than a rank or a diagonal; and the file, rather than the rank, is the first line from which a rook begins its attack.

There are 4 ways upon which a major piece can be established on an open or semi-open file:

  1. The file is already open and all that needs to be done is to bring the rook/queen onto it
  2. The rook is maneuvered such that it stands in front of its own pawns (e.g. the King's rook being lifted onto the 3rd rank via Rh1-Re1-Re3-Rh3)
  3. The pawn in front of the rook makes a capture and moves to an adjacent file, thus opening up the original file
  4. The pawn in front of the rook advances and is sacrificed to open up the file.

So what happens when one has gained control of an open file, and wants to use it to attack his opponent? Nimzowitsch has the answer for this:

"The idea which lies at every root of operation in a file is the ultimate penetration into the 7th or 8th rank"
-Aaron Nimzowitsch

Nimzowitsch expounded on these ideas in Chapters 2 and 3 ("Open files" and "The 7th and 8th ranks") in his work "My System".

To get a better understanding of how to exploit an open file, here's a simple position for you:

Anand - Ivanchuk
Amber Rapids 2001
Position after 33...Ne8
In the following diagram, White utilizes a pawn sac to clear the fle and pave the way for his rooks to the 7th rank:

34. e5! dxe5 35. Rd7+ Kf6 36. Ra7 Kg6 37. Rdd7 (D)


The rooks have penetrated into the 7th rank, and Anand was quick to finish off his opponent:

37... f6 38. Rd8 h5 39. Rda8 h4 40. Rxa6 Nc7 41. Rxe6 Nxe6 42. a6 Nc7 43. Ra7 1-0

When attacking a castled position, opening up the files close to the king is one of the typical ways of which the attacker's rooks gain access into the enemy camp. In the Sicilian Dragon, for example, White's main plan is to open up the h-file by sacrificing a couple of his kingside pawns, followed by an intrusion of his major pieces into Black's kingside. Black, on the other hand, wants to build a battery of major pieces on his semi-open c-file, where he can then attempt to break into White's queenside castled position. If either side is able to successfully execute his plan, the game often proves decisive.

Let's take a look at a typical Sicilian Dragon game and see how these files are utilized to attack the castled position:

Position after White's 8th move
In the following diagram, White tries deny Black access to the semi-open c-file by 9. Nxc6, but this merely allows Black to open up another avenue of attack-- the b-file-- with 9... bxc6

10. O-O-O Qa5 11. a3 Be6 12. g4 Rfb8

Black takes control of the c-file and starts preparing his attack on White's castled king

13. Ne2 Qb5 14. Qb4 Qxb4 15. axb4 Rxb4 16. Nd4 Bd7 17. c3 Rbb8 18. Bd3 c5 19. Ne2 a5 20. Kd2 Rxb2+ (D)


With the a and b-files controlled, the seventh rank secured, and an outside passed pawn at his disposal, Black had no difficulties converting the game into a win.

Our third example may not occur to you in an actual game, but it is always nice to appreciate the tactics and combinations that come with sacrifices. In the following puzzle, observe how the combination of sacrifices, coupled with the opening of the h-file, lures out the enemy king into a mating net. Take some time to calculate the variations before you scroll down:

White to play and win
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1. Qh6+!

Drawing the king onto the semi-open h-file

1... Kxh6 2. hxg6+ Kg5 3. Rh5+!

And this new combination lures the king into the fire of the e2 bishop.

3... Kxh5 4. f4+ Nxe2 5. Nf6+ Kh6 6. Rh1+ Kg7 7. Ne8+ Rxe8 8. Rxh7+ Kf8 9. Rxf7# 1-0


Ranks involved in the attack on the castled king

As we have seen earlier, the securing of an open file often allows the attacker inroads into the seventh and eigth ranks. These two ranks are especially sensitive portions of the defender's position, for it is where most of his pieces and pawns are placed. If the enemy rooks are allowed to break into the 7th and 8th ranks, then the subsequent maruding raids along the rank will be enough to wreck havoc in the defender's position.

To fully appreciate the weaknesses associated with these two ranks, let's study the following game by Afikba Rubinstein:

Rubinstein - Maroczy
Gothenburg 1920
Position after 30...Kh8
The open d-file has already been captured, and all that remains is for White to make preparations for an invasion of the 7th and 8th ranks. He does this by first pushing the pawn to h6:

31. h5 Nf8 32. h6!

White now threatens 33. Bh4 with a mating attack should Black play 32... gxh6

32... Ng6 33. Qe6!

Exploiting the weakness of the back rank. Now, 33... Rxe6 will be met by 34. Rd8+ while 33... Rce7 will lose to 34. hxg7+

33... Rf8 34. Rd7 gxh6 35. Bh4! 1-0


Seizing control of the 7th rank. The threat of 36. Bxh6+ forces Black to play 35. Nxh4, but even so it will not be able to stop eventual mate on h7 (36. Qe7 followed by 37. Qxh7#)

You can take a look at the entire game here:



Open diagonals involved in the attack on the castled king

Just like how the rook is the master of the open file, the bishop can be called the king of the open diagonals. There are many examples to show how bishops and queen pair up to occupy the long diagonals, before exploiting systems of weak squares within the enemy's camp to infiltrate into the castled position. If you have forgotten, here was one good example which I had shown to y'all a couple of months back: http://nushsblackknights.blogspot.sg/2013/07/opposite-colour-bishops-in-middlegame.html

Similar to a file, a diagonal has to be cleared of all influence before the occupying bishops and queen are able to exercise their full power along it. And this does not just mean the enemy pieces-- any of the attacker's own pieces which may get into the way should evacuate the diagonal before the proper launching of the attack. I mean, we surely don't want any cases of friendly fire right?

Plus you don't want to get points deducted
In the case of clearing a file, we have already talked earlier on about how the pawns blocking the rooks can pose a problem to this, and how these problems can be solved-- by posting the rook in front of the pawns, by letting the pawns capture and move to an adjacent file, or by advancing and sacrificing the pawn.

On the other hand, clearing a diagonal means that the pawns occupying the stretch of squares will also have to move out of the way, usually by advancing forward. This can pose a problem if the pawns are blockaded and unable to advance-- and it is usually solved by sacrificing a piece on a square controlled by the pawn. Take a look at the following example:

Alexander - Szabo
Hilversum 1947
Position after 20... Qd8
White recognizes that a clearing of the long a1-h8 diagonal will reap great benefits, for it gives a valley of attack for his bishop into the kingside castled position. This, coupled with the semi-open f file, should prove decisive if successfully executed.

But the problem lies with his pawn on e5... it is blocking the way, and it also cannot advanced since it is being blockaded by Black;s pawn on e6. To solve this problem, White decides to sacrifice his knight to clear the diagonal:

21. Nf6+! gxf6

If 21... Kh8, then 22. Qh4 also gives a powerful initiative

22. Qg3+ Kh8 23. exf6 Bxf6 24. Ne5!

Threatening moves like 25. Rxf6, 25. Nxf7+ and 25. Qh4 (If 25... Qxh4 then 26. Nxf7+ followed by 27. Nh6#)

24... Bxe5 25. Bxe5+ f6 26. Rxf6 1-0




Clearing the long diagonal. There is no defence to be found (26... Rxf6 is met by 27. Rf1)

Coming back to the Sicilian Dragon again, you can now see why it offers Black much more attacking chances than any other variation, mainly because of the fianchettoed bishop on g7:

Sicilian Dragon main line, after Black's 10th move
Once Black is able to clear the a1-h8 diagonal of both the enemy and his own knights, then the open diagonal offers the bishop an avenue of access into the queenside, which can then be combined with the semi-open c file to launch an all out storming of White's castled position. And it is from this where the Dragon earns its reputation as an aggressive opening from.

Note: You may have noticed that I have mentioned the Dragon many times throughout the course of these articles. Not that I'm encouraging you to play it, but the very nature of the position itself offers many attacking chances for both sides, thus it seems apt to be mentioned in these articles!

...

In Part 4, we will extend the discussion to look at how the different types of pieces and pawns play a major role in the attack against the castled position

Links:
Part 1: http://nushsblackknights.blogspot.com/2013/08/how-to-attack-part-1.html
Part 2: http://nushsblackknights.blogspot.com/2013/08/how-to-attack-part-2.html

Sources:
http://www.imod.co.za/2009/03/29/ssg-battlefield-2-knife-challenge/
http://forum.worldoftanks.asia/index.php?/topic/18402-fines-and-premium-accounts/
"Art of Attack in Chess" by Vladimir Vuković

Monday, August 19, 2013

How to attack: Part 2

Attack against the castled king

The attack against the castled king is the most common type of attack in many games, since many experience players would already have castled early in the opening. Because of the nature of this topic, I will have to span it over quite a few posts to cover the various aspects involved in the attack against the castled position.

We begin with a few general considerations.

One must note that an attack against the castled position is different-- and often more difficult-- than the attack against an uncastled king. The weaknesses which we discussed in Part 1-- the e-file and the weak f squares-- diminish greatly after castling, and many new dynamic possibilities open up for the player. He brings his rook into the game, clears the e1/e8 square for a possible attack, and has made the necessary preparations to establish a line of communication between his rooks (i.e. clearing the back rank such that his rooks protect each other).

So before attacking the castled position, one must take in a few considerations-- namely, the features of the castled position, and the feasibility of an attack in that theatre.

For one, castling in itself creates a positional feature that changes little throughout the game. When the king is still in the centre of the board, it has the liberty of choosing whether to remain in the middle, or to castle kingside or queenside. But after castling on one wing-- and taking into account that castling is irreversible-- the king already commits himself to a protective shelter on one side of the board. And it is in that area which he stays throughout the most of the game, and only until the endgame does he leave his command post and joins in the fight for the centre.

It is precisely this fixed nature of the castled position that the opponent will naturally take into account during his planning. Ever wondered why both sides deliberately castle on opposite wings in the Sicilian Dragon, Yugoslav Variation? Because they know that their adversaries cannot change the positions of their kings easily-- thus making it easier for both sides to launch attacks on parallel wings.

Next, the various strengths and weaknesses around the castled position will affect the way in which the attacker deploys his pieces for the assault. The removal of a fianchettoed bishop leads to the creation of weak squares that the attacking pieces use as their points of entry (not trying to reference anything). The clearing of a file/diagonal gives avenues of access to the enemy rooks or bishops. And the classic bishop sacrifice on h7/h2 destroys the protective pawn cover, allowing for an all-out storming of the position. These are just a few of the many features in an attack against the castled king.

Lastly, one must remember that an attack against the castled position involves the shifting of pieces to one side of the board, which will inevitably lead to the decentralization of the attacking pieces. This means that should the attack fail, the decentralized position of the attacker's pieces will usually be disadvantageous to him-- especially if the defender himself launches a counterattack on the other wing. It's a little like sending all your troops out to attack the enemy, and leaving no one behind to defend your own castle:

"Bad news, sir. While our million man army was sieging the enemy, a hundred men arrived and took our city"

So let's get started. The first feature that we will look at in this article:


Squares/Focal points involved in the attack against the castled king

Depending on the arrangement of the pieces and pawns around the enemy king, the strength of the squares in the castled position will vary. It is mostly true that a weak pawn structure in the castled position will open up weak squares, and these weak squares become what is known as focal points-- that is, points where the opponent should drive his attack against. These squares form the corridors through which the attacking pieces enter and deliver mate.

Take a look at the following hypothetical position:


Oh this following position, Black's pawn structure opens up holes on the dark squares which White must inevitably use to deliver mate. Over here, the main focal point will be the g7 square, on which the mate will be delivered (1. Qh6 followed by 2. Qg7#), and the dark squares around this is known as a system of weak squares, throughout which White finds a path into the castled position.

In a kingside castled position, the two main focal points of attack are the g7 (g2 for White) and the h7 (h2 for White) squares, as these two are the most accessible points for the attacker. Attacks on the f7/f2 squares are also possible, but not as common. For today, we'll take a look at the g and h squares.


The h-squares as the focal point

The h7/h2 square is probably the most frequent point of attack (yes, more common than the g squares) against a castled position, simply because it is so easily accessible to the attacker.


To use the above diagram as an example, the h7 square comes under fire from a bishop on d3 (which is the natural developing move for the bishop), and White's knight can easily hop to g5 rather than f5 or h5. And it is precisely this ease of clearing the square that leads to stuff like the classic bishop sacs on h7.

However, the main drawback of attacking the h7/h2 square is that it is easier for the opponent's king to escape (by fleeing to the f-file) as compared to an attack on the g squares. Thus, most attacks against the h7/h2 squares can be sparked easily by a clearance of the square, but the real challenge comes when the attacker tries to stop the enemy king from escaping.

For example, in the case of the classic bishop sacrifice, one can simply clear the h7 square with 1. Bxh7. But after that, one must take into account the numerous variations in which the enemy king tries to flee after 1... Kxh7, after which the king has options to flee to g8, h8, g6, h6-- depending on which of these squares are covered or blocked. And then there are also the variations where the king declines the sacrifice by moving to f8 or h8-- seems like it's not a very easy task to calculate all of them!

Let take a look at a typical attack against the h7 square:

Szabo - Kotov
Groningen "Staunton Memorial" 1946
Position after 15...h6
White first eliminates the defending knight on f6 before clearing the h7 square:

16. Nd5! exd5 17. Bxf6 Bf5

The only reply, since recapturing the bishop leads to mate with 18. Qh7#

18. Qxf5 g6

White then went on with 19. Qxg6+ fxg6 20. Bxd5+ Rf7 21. Bxe7 and won through his material advantage, although the variation 19. Bxe7 gxf5 20. Bxf8 would have been more straightforward

Now, the following example shows the main challenge when attacking the h7/h2 square: How to stop the enemy king from running away successfully

Spassky, Boris - Tal, Mihail
Montreal 1979
Position after 20. Qd2
In the following position, Tal-- being Tal-- struck with the classic bishop sacrifice:

20... Bxh2+! 21. Kxh2?

Declining the sacrifice and fleeing with 21. Kf1 would have been better, even though Black still stands at an advantage in both material and position

So now, imagine if you're Black, and you want to follow up your last move with a mating attack. Oviously the two candidate moves are 21... Ng4+ and 22... Rg5+, so which will you choose?

Let's first take a look at 21... Ng4+


Now look at the position. The White king has 4 possible escape routes: Kg3, Kh3, Kh1 and Kg1. Are you going to spend all day long calculating them, especially in scenarios where you probably have less than 15 minutes on your clock?

How about we put this aside for now, and look at the 21...Rh5+ variation:


And now by looking at the position we can see only two variations we need to consider, namely 22. Kg3 and 22. Kg1. Before you scroll down, try to take some time (you can use a chessboard to help you if you want) to calculate what are the possible ways for Black to deliver his attack in the two different variations.
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22. Kg1 Ng4! 23. Qf4 (If White moves stuff such as 23. Re1, Black threatens 23... Rh1+ 24. Kxh1 Qh4+ 25. Kg1 Qh2+ 26. Kf1 Qh1#) 23... Qh4! and there is no defense against mate on h1.

OR

22. Kg3 Ne4+! 23. Bxe4 (23. Kf3 Nxd2+ 24. Kg4 Qg5#) 23... Qh4+ 24. Kf3 Rxe4 with an unstoppable 25. Re3#

And there you go, the variations after 21... Rh5+. In actual fact, post game analysis showed that 21... Ng4+ also wins for Black, but in a longer and harder way.

The third example I want to show is slightly different from the previous two, but STILL VERY IMPORTANT! It serves as a reminder that sacrificing mindlessly without enough calculation will lead to the backfiring of the attack, with serious repercussions:

White to move
White correctly realizes that his d3 bishop is under danger; but instead of retreating it to e2 and retaining the advantage of the bishop pair, he makes a miscalculated sacrifice:

1. Bxh7+? Kh8!

White was probably hoping for 1... Kxh7, after which 2. Ng5+ followed by 2. Qh5 leads to the typical mating attack after the classical bishop sacrifice. However, he failed to calculate the variation where Black declines the sacrifice-- and now his bishop has nowhere to run to!

2. Ng5 Qxd1 3. Rfxd1 g6!

And no defense can be found against 4...Kg7 followed by 5...Rh8, winning two minor pieces for a rook. Once again, this emphasizes the importance of careful calculation, rather than making mindless sacrifices!

And thus to repeat my earlier point: In an attack against the h7/h2 square, the challenge lies not in how to clear the square itself, but rather how to carry out the mating attack in subsequent variations after that.


The g squares as the focal point

As explained earlier, clearing the h squares is easier than clearing the g squares, mainly because the g7/g2 squares are less easy to access-- the attacker's pieces will have to do some fancy bit of maneuvering before they can even get the square under fire:


However, one thing to note is that as compared to an attack on the h square, an attack on the g square is more dangerous. The main reason lies in the area of operations around the g square: Once cleared, the attacking pieces also exert their control over the squares along the f and h files, making it more difficult for the king to flee along these files. In contrast, a clearance of the h squares still offers the defender chances to utilize the f-file for escape, which often poses a challenge to the attacker.

Thus, the main challenge for an attack on the g7/g2 square lies in how to get your pieces to clear out the square-- once that is done, the subsequent mating variations that follow are often not too difficult to calculate.

We start off with a simple example:

Black to move
Black has maneuvered his pieces with some difficulty, but now they're poised to strike the g2 square.

1... Nf4 2. Nxe4 Qh3! 0-1

There is no parrying the threat against g2-- 3. gxh3 leads to 3...Nxh3#. And this is a simple highlight of how dangerous an attack on the g square can be as compared to an attack on the h square.

The next example is a game by the famous attacking player and 4th World Champion Alexander Alekhine. It was also the first and only time Alekhine defeated Lasker:

Alekhine, Alexander vs Lasker, Emanuel
Zurich 1934


In this game, note how White maneuvers his pieces into a position ready to attack the g7 square. On the 20th move the battle for the g7 square begins, upon which the Black king already has relatively little space to run.


Multiple focal points (a system of weak squares)

Sometimes it is not just one weak square in the defender's camp which can be exploited-- very often, the attacker can make his task easier by creating two or even three focal points from which he attacks the enemy king. One example of this will be the case where a fianchettoed bishop is removed from the kingside castled position, creating a series of weak squares of the same colour in the area-- or what is known as the system of weak squares.

When there are multiple focal points within the castled position, the attacker can use his pieces to control both focal points at the same time and alternate attacks on them, thus making it harder for the defender to carry out his task. In the case of a system of weak squares, the bishop and the queen are always the favourite pieces as they dominate squares of a certain colour.

As many of you should be quite tired by now after reading such a long article, we'll just take a look at one final example illustrating the topic of multiple focal points:

White to move
An experienced eye will be able to quickly identify the holes in Black's kingside position-- namely, the system of weak squares f6, g7 and h6. It is through these dark-coloured squares that White forces his entry in:

1. g6! Kh8 2. Qh6 Rg8

White can't go any further in his threats against g7, but the excellent placement of the Queen offers a new opportunity for an attack on h7. All that is needed is for White to lift a rook onto the h-file.

3. Rf3! (threatening 4. Rh3) 3... Bxf3 4. gxf3 d5

Black's last move is forced, due to the threat of 5. Qxh7+ followed by 6. Rh2#

5. f4!

And Black can only prevent mate for a move or two by sacrificing his queen on f4. The double threats against g7 and h7 proved too much for Black to defend.

...

In Part 3, we will extend our discussion of the attack against the castled king to the ranks, files and diagonals involved in the assault.

Links:
Part 1: http://nushsblackknights.blogspot.com/2013/08/how-to-attack-part-1.html

Sources:
http://www.newsecuritylearning.com/index.php?start=10
"Art of Attack in Chess" by Vladimir Vuković
"How to Calculate Chess Tactics" by Valeri Beim

Sunday, August 18, 2013

Endgame Studies Part 2: Evaluation/Planning and Should You Trade?

Endgames in general look simple as there are much less pieces on the board. However, in certain positions, the certainty is misleading, as there are probably tactical threats or stalemates at every position of the game. We probably know the principles of endgames, which is to place your King and pieces as actively as possible and defend/attack weaknesses. However, at every move, there is a point where you are thinking if you should exchange pieces, and whether you are able to have a better endgame after the trade.

In an endgame with only Kings and Pawns, there are a lot of tactics in the endgame which can drastically change the outcome of the game, and most of them involve changes in tempo resulting in loss of pawns. This is due to the fact that each side has only 1 attacker and defender of pawns, and it is easy to miss out those moves.

We know several things about Pawn Endgames:
  1. Both Kings need to be actively placed near the area of battle.
  2. If the winning side only has extra a-file or h-file pawns, then the opponent has higher drawing chances due to stalemating by placing his King on the Queening Square.
  3. The passed pawns, if the opponent King is nearby, should not advance too fast ahead. It is important to make sure that you can outmaneuver the opponent's King from the file before pushing the pawn forward.
Hence, it is important to make sure that you are able to win the pawn endgames before trading off your pieces.

There are several positions which have been studied in detail, with results of forced wins/draws. We will look into those in the next few posts to come, and they serve as a good platform of deciding to trade pieces.

What should you think about in the endgame?
  1. Tactics: Are there any hanging pieces/pawns that you can take without danger? Or sudden checkmates?
  2. Material Balance: Consideration of how each of your pieces are able to attack your opponents' pawn chains, and how they can work together to pile up the attack on the base of the pawn chains. As an example, a Bishop of the wrong colour is unable to attack the opponents' pawns, but it can slow down the advances of pawns on both sides of the board. A Knight is able to fend off pawns on one side of the board, but does poorly when there are pawns on both sides of the board and are actively advancing with protection.
  3. Pawn Structure: Where are the weaknesses in your pawn structure? Are you able to find ways to make sure your opponent is unable/finds it difficult to attack those weaknesses?
  4. Position Imbalance: Are there any good open files/diagonals and outposts? Where are your pieces right now? Are they able to be swiftly mobilized towards attacking/defending weaknesses or restricting the opponents' pieces?

Next, do the same thing from your opponent's point of view. It is good that at the start, we do our analysis on paper. This is to help us consider our candidate moves with more perspective. After knowing all these, it is important to make a plan (an idea such as piling an attack against the base of the pawn chain, and thinking through the order of moves to make, and making sure not to fall into any tactics.) and follow it through.

Going back to the original question: Should we trade pieces? The answer is that if the result of trading favours you in the majority of the 4 areas, you should proceed to exchange pieces. One example is the exchange your wrong colour bishop for your opponent's knight when all the pawns are on the Kingside. Many positions are less clear-cut, but as long as you consider all the options you have, you are likely able to make better decisions along the way.

As you apply these, you will surely be able to improve your winning/drawing chances in any chess game!

Links:
Part 1: http://nushsblackknights.blogspot.com/2013/08/endgame-studies-part-1-opposition-in.html

Endgame Studies Part 1: The Opposition in the Endgame

Hey guys! This is my first post for the blog! :)

Today we'll start off with the art of using the king to the fullest potential in the endgame. In the endgame where both sides have almost equal material, the king is a very useful piece. It can act as an extra defender of your pawns and attacker for your opponent's pawns. However, your opponent can use his own king too, so we have to learn ways to outmaneuver the opponent.

One of the key ideas between the battle of Kings is the Opposition. Take a look at the following position:


Diagram 1: The Direct Opposition

Notice that both Kings are 2 spaces apart. In this scenario, neither King can move to the other side behind the enemy king if it was their move. The King to move first will inevitably allow the opponent's king to cross into his territory. In an endgame with pawns, such an opportunity given to the opponent will result in a harder position to win or draw with.

Now look at the following position:


Diagram 2: Puzzle

Your white King is on a1, and the black King is on a8. Assuming that the aim is to move your King to h8, how would you do so? (White to move)

The main way to do so is to move so that you can reach the opposition as shown in Diagram 1 with it being your opponent's turn. However, both Kings have many options it can travel in, and it will be very hard to calculate each of the many options available. There is 1 way to "see" which is the "right move" to force the opposition. This idea is known as "Indirect Opposition".

The main idea is to put your King at a position where the rectangle formed by the 2 kings have all 4 corners having the same colour. Examples are shown in the positions below:





Whenever the opponent King moves, move forward and to the right square (that creates the rectangle with 4 corners having the same colour) at the same time. By this way, you can force your opponent into a direct opposition, and enter into his territory.

Back to the position in Diagram 2, it's not hard to see the winning move:

1) Ka2!

Now taking the Indirect Opposition.

1) ... Kb8

A good defence. Ka7 and Kb7 loses to Ka3/Kb3 respectively, and after coming forward, they lose the opposition and the game. Now, White cannot go Ka3, as even after gaining the opposition, he will be stuck on the Queenside, and black is able to block the advance towards h8.

2) Kb2! Kc8
3) Kc2 Kd8
4) Kd2 Ke8
5) Ke2 Kf8
6) Kf2 Kg8
7) Kg2 Kh8
8) Kh2

Now, no matter what black plays, he cannot gain the opposition, and the white King can travel to h8.

The following idea is important in endgames when you need to enter the opponent's territory with your King to attack his pawns and fight for the win! Learn to calculate and play endgames using the idea of the Direct and Indirect Opposition, and you'll be able to win more endgames.

Saturday, August 17, 2013

How to attack: Part 1

We'll give 'em the bayonet, sir!
Attack-- one of the most coveted-for skills in club-level play. As many a general has said, "the best defense is a strong offense", and indeed I find that many of you prefer to attack rather than stay on the defense.

But what happens if one does not launch his attack properly, or launches it at the wrong moment? Then very often he will land himself in trouble after his attack fails, and finds that he has to deal with his opponent's new threats.

Thus, I have decided to write this series of articles unveiling the intricacies behind various attacking positions, and how or when one should attack. But first, a few important words must be said:

It is IMPORTANT to understand that in order for an attack to be successful, the attacker must possess some sort of superiority in the area he is about to launch his operations-- not just material, but also of position and tempo. It is of little value to attack a well-defended position with insufficient strength, for it only saps you of energy and invites the opponent for a counterattack.

Another factor for attacks to be successful is that of a temporal advantage-- the ability to carry out an attack without the opponent having enough time to organize a skillful defense or launch a counterattack. Most of the time this temporal advantage is based on the attacker's positional pluses; you might be able to commence an attack based on a dominant pawn centre, a greater mobility of pieces, or weaknesses in your opponent's pawn structure, just to name a few.  

That said, it is crucial to know when is the right time for one to launch an assault-- doing it too early may weaken one's position and backfire, while doing it too late will allow the defender to find effective countermeasures

And it is precisely this difficulty of launching the attack at the right time that has caused many master level players to shy away from the attacking style, and turn to positional chess (this is also why so many top-level games end in draws). But at our level of play, it is still possible for many players to adopt the attacking style, thus producing many decisive games in the process. So if you're the sort who loves to attack, do not get too discouraged!

All ready? We shall start with the simplest topic:


Attacks on an uncastled king

Castling exists for a reason. In the opening and middlegame, your king is exposed in the middle of the board-- castling thus makes it easier for you to bring His Majesty to safety without having to spend a few extravagant moves. And that is why so many chess trainers emphasize on us the importance of castling early.

While I do know a few friends who are not in favour of castling, these are usually the types who abandon castling in favour of launching quick and early attacks. And mind you, this requires a fair bit of skill and LOTS of guts. Otherwise, the safest plan for all of us will be to castle early when we can.

So let's say you meet into an opponent who fails to castle early (and funnily enough these are usually the young kids). How will you then punish him?


Look at the diagram above, which shows the position of a king which has yet to castle. You can see that there are two main weaknesses-- the king can become exposed if the e-file is opened, and the f7 square in Black's camp (f2 for White) is weak, since it is guarded by the king alone. It is not surprising that many attacks on the uncastled king are often driven towards these two weaknesses.


Plan 1: Attack on the e-file

The first and most obvious requirement for an attack along the e-file to be justified is that the opponent's king is stuck on it, and cannot move anywhere or castle quick enough to get away from the line of attack (like DUR). Imagine stacking up all your forces to break open the e-file and hammer it down, and then at the critical moment your opponent's king manages to castle to safety!


The next requirement for such an attack to materialize will be a significant degree of control by the attacker along the e-file. This can mean stuff like the attacker's rooks controlling the open/semi-open e-file, or the attacker being able to quickly post pieces along that file to exert pressure on it.

And such it is obliged for the attacker to increase the pressure on the e-file as quickly as possible, either by doubling rooks/queens on the file or attacking one of the pieces that is protecting the uncastled king. Once the file is broken through, then the attacker can bring in his storm troops with full bearing onto the opponent's exposed king.

But most of the time, the defender will have a piece posted on e7 (for Black) or e2 (for White) to protect the king; in such cases, the attacker's plan will be to concentrate all his efforts in undermining this critical square, making it the main battleground of the game.

Let's take a look at the following position, which was reached after the moves:

1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. d4 exd4 5. Nxd4 Bb4 6. Nxc6 bxc6 7. g3 Qe7 (D)

Meesen - H. Muller
Correspondence Game 1928
Position after 7...Qe7
With his last move Black counters White's plan (8. Bg2 followed by 9. O-O) by attacking along the e-file. Now, White can choose to play 8. e3 and dampen the attack, though at the cost of weakening his pawn structure. Instead, he continued:

8. Bg2 Ba6 9. Qd3 d5 10. b3 d4! (D)


Black now switches his point of focus temporarily from the e-file to the a5-e1 diagonal, where White's knight is still pinned to the king. If White now tries to grab with 11...Bxc6+ and 12...Bxa1, Black will reply with the continuation 11. Bxc6+ Kf8 12. Bxa8 Bxc3+ 13. Bd2 Bxa1, winning a piece. Now, the game continued:

11. Qxd4 Rd8 12. Bxc6+ Kf8 13. Bd5 Rxd5! 0-1

White cannot recapture the rook since 14. cxd5 leads to 14... Qxe2#. Play returns to the e-file at the critical moment.


Plan 2: Attack on the weak f-squares

By the weak f-squares I am referring to the f7 square for Black, and the corresponding f2 square for White. In the early stages when the king has yet to castle, these squares are most vulnerable as they are covered only by the king and will exposed his position once the pawn is removed. Many attacks on the uncastled king are directed with a sacrifice on the f7/f2 square, followed by a mating attack.

After kingside castling, the rook helps to cover the square and decrease its vulnerability, while after queenside castling, it is pointless to use the f7/f2 square as the focal point for the attack. Once again this reiterates the importance of castling early in the game!

Let's look at the following example of a sacrificial attack on the f7 square:

1. e4 c5 2. Nf3 Nf6 3. e5 Nd5 4. Nc3 e6 5. Nxd5 exd5 6. d4 d6 7. Bg5 Qa5+ 8. c3 cxd4 9. Bd3 dxc3 10. O-O cxb2 11. Rb1 dxe5 12. Nxe5 Bd6 (D)

Keres - Winter
Warsaw OL, 1935 
Position after 12. Bd6
White has given up several pawns for a huge lead in development. Now, he decides the game with a sac on f7:

13. Nxf7+! Kxf7 14. Qh5+

An important thing to note here: When you're attacking, always follow up any sacrifices made with an attack as soon as possible! Failure to do so will give the defender ample time to consolidate his defences (e.g. artificial castling by ...Rf8 and ...Kg8) and the attack wears off quickly. To use an analogy, it's like calling down a surprise artillery barrage on the enemy, and then dallying around and attacking one hour after the barrage has ended:

Ok so after this barrage is over, I'll give you guys one hour to prepare your defenses, then we'll send our troops over for a nice little battle

No, don't do that. Attack IMMEDIATELY, while the enemy is still reeling from his initial shock and is incapable of offering strong resistance.

14... g6 15. Bxg6+ hxg6 16. Qxh8 Bf5 17. Rfe1 Be4 18. Rxe4 dxe4 19. Qf6+ 1-0

A short and sweet ending.

...

To summarize what we have learned so far, an attack on the uncastled king usually involves two main plans: 1. An attack along the e-file, or 2. An attack on the f7/f2 square

And to finish off Part 1, I want to show the most striking example of an attacking game where the losing side had yet to castle. The "Opera Game", played between Paul Morphy and two strong amateurs in 1858, continues to amaze many till today. Many chess trainers continue to use the game as an example to emphasize the importance of early development and the vulnerability of an exposed king in the centre.

In this game, note how White utilizes the open files and diagonals to tie down the opponent's pieces and catch his king in the centre.


Sources:
http://knowyourmeme.com/memes/rage-guy-fffffuuuuuuuu
http://en.wikipedia.org/wiki/Barrage_%28artillery%29
"Art of Attack in Chess" by Vladimir Vukovic

Thursday, August 15, 2013

Pawn Structures and Pawn Chains: Part 6

The pawn chain is not a unique feature of the Advance French-- it is also present in many other closed games, notably the King's Indian.

In fact, many King's Indian games feature a closed position where the central pawn chain divides the board into two, thus provoking both sides to attack on opposite wings (remember what we talked about in July?). Today we will examine such a game, played none other than the great Mihail Tal himself.

The great Mihail Tal

Larsen, Bent vs Tal, Mihail
Eersel 1969


1. Nf3 Nf6
2. c4 g6
3. Nc3 Bg7
4. e4 d6
5. d4 O-O
6. Be2 e5
7. O-O Nc6
8. d5 Ne7
9. Ne1 Nd7
10. Nd3 f5
11. Bd2 Nf6
12. f3 f4
13. c5 g5 (D)


Larsen has quickened his attack by using a slightly different move order. He has omitted the prepartory move b4 in order to attack the d6 base more quickly, and try to open up the c-file.

14. Rc1 Ng6
15. Nb5

White was hoping to provoke 15... a6, after which 16. cxd6 axb5 17. dxc7 Qd7 18. Qb3 gives him a strong advantage.

15... Rf7
16. cxd6 cxd6
17. Qc2 g4

Disregarding the knight on b5, Tal strikes back in his typical manner. A more cautious approach would have been 17... Ne8 before playing 18... g4

18. Nc7 gxf3
19. gxf3 Bh3 (D)


By advancing his g pawn, Black seeks counterplay on the kingside in order to counter White's kingside activity. He is ready to sac his pieces in exchange for a powerful attack on the enemy king.

20. Nxa8 Nxe4!

This move probably took Larsen by surprise; he had been hoping for 20... Qxa8 21. Nf2 Bxf1 22. Bxf1, where he will then be able to establish a powerful bishop on h3. Had he forseen Black's move, he would have been more cautious and played 20. Ne6 instead.

21. fxe4 Qg5+
22. Kf2 Qg2+

Of course, Black could have drawed with a perpetual on Qh4+, but Tal was not satisfied and wanted to play for a win.

23. Ke1 Nh4 (D)


24. Be3?

Confused by this sudden change of events, White missed the strong continuation 24. Nf2!, where after 24... Nf3+ 25. Kd1 Nd4 26. Qc3 White fends off the attack. Now, little can be done in the way of Black's attack:

24... Qxe4
25. Bf2 f3
26. Bxh4 Qxh4+
27. Nf2 fxe2
28. Qxe2 e4
29. Rg1

29. Rc7 loses to Bxf1 30. Kxf1 Rf5, while 29. Rc4 loses to Bxf1 30. Kxf1 Qxh2

29... e3
30. Qxe3 Re7
31. Rxg7+ Kxg7
32. Rc7 Bd7
33. Rxd7 Rxd7
34. Qxa7?

In trying to save his knight, White has placed his king in danger. More stubborn would have been 34. Qc3+ Qf6 35. Qg3+ Kf8 36. Nd3, activating the knight.

34... Re7+
35. Kd1 Qc4
36. Qb6 Qf1+
37. Kd2 Re2+
38. Kc3 Qc1+
39. Kd4 Qe3+
40. Kc4 Rc2+ (D)
0-1


The same method of play against the pawn chain, coupled with the kingside attack, brought Tal success. And now to wrap up this entire series, I will summarize the basic points to take note when playing with or against the pawn chain:

  • As the attacker, your pawn chain gives you much space in the centre, while the forward wedge controls vital squares within the enemy camp. Thus, you should utilize these squares to bring in your pieces for the attack. As the enemy's central pawns are blockaded, you can also seek to make flank attacks on them.
  • As the defender, your countermeasures will be to attack the base of the chain, and bring in as many pieces and pawns as possible for a siege of the base. Should a new weakness appear in the attacker's camp, you can then transfer your attention over to the new weakness, before returning to attack the chain again in the endgame
  • At the critical moment when the chain falls apart, the attacker should attempt to bring his pieces into the centre. If he succeeds, then his pieces will exert suffocating pressure within the defender's position, while the enemy blockaded pawns become exposed and vulnerable. If he fails to do so, then the formerly blockaded pawns will advance with all their pent-up energy, thus changing the nature of the game and turning the tables.
  • Very often, the centre can become closed, in which play will naturally be transferred over to the wings. Both sides will usually seek to make parallel attacks on opposite wings.

This, I hope, will aid you in your efforts both with and against the pawn chain in future games.

Links:
Part 1: http://nushsblackknights.blogspot.com/2013/07/pawn-structures-and-pawn-chains-part-1.html
Part 2: http://nushsblackknights.blogspot.com/2013/07/pawn-structures-and-pawn-chains-part-2.html
Part 3: http://nushsblackknights.blogspot.com/2013/08/pawn-structures-and-pawn-chains-part-3.html
Part 4: http://nushsblackknights.blogspot.com/2013/08/pawn-structures-and-pawn-chains-part-4.html
Part 5: http://nushsblackknights.blogspot.com/2013/08/pawn-structures-and-pawn-chains-part-5.html

Sources:
http://en.chessbase.com/home/TabId/211/PostId/4008285
"Understanding Pawn Play in Chess" by Dražen Marović