Friday, December 30, 2016

Kickoff 2017 Tactical Challenge

Giving them out early because I will be on duty during the New Year.






Have fun, and Happy New Year to all!

Thursday, December 29, 2016

A story of doubled pawns: Part 4

As promised, we will be looking at instances of doubled pawns affecting the endgame. Now we know that due to their slow mobility and inability to protect each other, they are not very effective in offensive operations. Such is also true in the endgame. Take for example the famous rook-pawn endgame:

Position 1: A drawn rook-pawn endgame

Anyone with basic endgame knowledge knows this is a draw so long as Black gets his king to the promotion square. But if we added another White pawn anywhere along the a to g-files, then the presence of two passed pawns spells doom for the Black king.

What if we placed that extra pawn on the h-file, creating doubled pawns? Then the additional material makes no difference, because the rear pawn cannot provide any support. Neither can he hope to become a queen himself because his front comrade is blocking the way.

"Coming in one at a time ain't gonna help ya, mate"

It is however interesting to note that for non-rook pawns, the extra pawn does make a difference even if in the form of doubled pawns!

...

Another case of unsuccessful offensive campaigns involving doubled pawns would be the opposite-colour bishops endgame:

Position 2: A drawn opposite-colour bishops endgame

This is another basic draw. Even though Black's king is in the middle of nowhere, he just needs to keep his bishop on the long diagonal, prepared to be sacrificed should the enemy pawn advance.

If we add an extra pawn behind the existing one, White wins since he can advance his pawn and exchange it for Black's bishop. He will still have another pawn left to promote.

But if Black now gets his king involved in the action, then both king and bishop can work to stop the pawns, and the presence of extra pawns behind won't make a difference:

Position 3: Doubled pawns won't help if Black's king is near

This is where the weakness of doubled pawns stand out. Once again, the rear pawn can't do anything to help the advance, since both enemy pieces guard the forward square. It doesn't matter if there are 3, 4 or even 5 pawns waiting in line!

Nope, White isn't going anywhere

...

One more example we will look at is the Philidor Position. From two earlier articles here and here we know this is another draw for the defender, regardless of which side to move.

Position 5: Another draw

Are the results any different if White had another pawn on d4? No, Black can still draw, but he needs to be a little more careful. The extra pawn means the White king has more chances to seek shelter from the rook checks!


Can doubled pawns be good in an endgame?

Having seen so many endgames where having doubled pawns is as good as having only one pawn, one naturally wonders if the opposite can be true. Can doubled pawns actually benefit a player in the endgame?

In all the examples we saw so far, the side with doubled pawns is hampered when using them in the offensive. But these unique foot-soldiers, while weak in the attack, turn out to be very useful in defensive operations.


Position 6: White's pawn majority proves decisive


In Position 6, Black's passed pawn is rendered useless, and White will simply advance his pawn majority on the other wing to create a passed pawn and an effortless win.

Enter doubled pawns, and suddenly White cannot advance his pawns without giving Black a passer of his own!

One real life example of this occured in the game Eliskases - Bogolijubov 1939, where Black was a pawn up in the endgame, but couldn't create a passed pawn due to the power of White's doubled pawns:


Wrapping up

From what we learned so far, it can be concluded that doubled pawns are generally bad for attacking but very valuable in defense (with important exceptions, of course). This is also true in the endgame, judging by our earlier examples.

In Part 5 and the final article in this series, we will wrap up with a few miscellaneous but interesting games involving the doubled pawns.

Links:
Part 1: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-1.html
Part 2: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-2.html
Part 3: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-3.html
Part 4: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-4.html
Part 5: http://nushsblackknights.blogspot.com/2017/01/a-story-of-doubled-pawns-part-5.html
Sources:
"Silman's Complete Endgame Course" by Jeremy Silman
https://www.chess.com/article/view/the-truth-about-doubled-pawns-part-3
https://en.wikipedia.org/wiki/Battle_of_Stirling_Bridge

Saturday, December 24, 2016

Christmas Tactical Challenge 2016

I'm getting really predictable. Who can miss an important date without some good puzzles?





Have fun, and Merry Christmas!


Sources:
http://www.today.com/home/5-tips-keep-your-christmas-tree-alive-through-holidays-t58821

Saturday, December 17, 2016

World Chess Championship 2016 Highlights: Part 2

Today we will continue on our analysis of selected WCC 2016 games. While in Part 1 we saw a simple victory by Carlsen in the rapid tiebreakers, this time we will look at the multiple times he tried to break down Karjakin in the classical games - and failed. Rounds 3 and 4 of the match were hailed as miracle escapes by Karjakin, as well as a showcase of his unwavering defensive skills.

Maybe if you fire enough rounds, one will hit him

In both games, we will see how close Carlsen got to demolishing his opponent, yet Karjakin stood his ground and managed to split the points after more than 7 hours of play.

A close shave for the Russian GM!


Carlsen vs Karjakin, WCC 2016 Round 3

As both rounds played well into the endgame, naturally there will be groans of despair should one try to click through every individual move. To make things more interesting, I have taken a leaf out of GM Daniel King's video, and divided the endgame of Round 3 into several key positions:

Game 1, Position 1 after 22... Kf6

Position 1. Both sides have simplified into a rook + bishop vs rook + knight ending. Although having pawns on both sides of the board usually favour the bishop, here there are so many pawns the position is rather cramped, thus the knight has a slight edge.

Carlsen, as White, continued 23. Nc4 followed by 24. Re8, taking control of the e-file and gaining better placement for his pieces. Karjakin on the other hand attempted to open up the position to help his bishop.

Game 1, Position 2 after 31. b3

Position 2. Although White had the initiative from the earlier position, Black has managed to generate some counterplay with his rook on the enemy's 2nd rank. His pawns are also ideally located on light-squares, giving his dark-squared bishop free reign.

One suggested continuation here is 31... d5, fixing White's queenside. Although Black drops a pawn after 32. Rg5, he can get sufficient counterplay against the queenside weaknesses with 32... Ke6 33. Rxg5 Bg7!

Instead, Black in his haste to further open the position for his bishop, played 31... c5? weakening his pawn structure and handing the advantage to White.

Game 1, Position 3 after 61. Kf3

Position 3. White already has the edge here thanks to his extra passed pawn, although Black has a blockade on it. However, after further mistakes by Black, White managed to infiltrate his opponent's kingside via the light squares, pushing him back with king and both pieces and gaining a huge advantage.

Game 1, Position 4 after 70... Kxf5

In our final position, we see that Karjakin has given up his remaining minor piece to prolong the struggle. Naturally most of us would think that it should be an easy win for Carlsen, but there is a catch: If Black can win the b3 pawn, the resulting rook + knight vs rook endgame is a draw.

In his attempts to hold onto b3, Carlsen slipped and gave Karjakin valuable time to generate counterplay with his h4 pawn. The game was eventually drawn on move 78.

Enough talking, let us play out the endgame with the 4 positions described:


What can we learn from this game?

  1. Sometimes, it is alright to damage your pawn structure to gain better piece activity... but sometimes it's not. You need to have sound analysis of the position before making such a decision
  2. When defending a rook endgame, avoid trading off the rooks, and keep your rook active by finding targets in the opponent's camp
  3. Similarly, when down on material, trade pawns instead of pieces, so that your opponent does not get easy king-pawn endgames


Karjakin vs Carlsen, WCC 2016 Round 4

For those who have been following my doubled pawns series, this game will already be familiar to you: Carlsen obtained a huge advantage by taking control of the light-squares and b-file, despite having doubeld pawns. So how did Karjakin defend? Today we will look at the endgame, where similar to Game 3 Carlsen missed an opportunity and allowed his opponent to build a fortress.

Once again we divide the endgame into 3 elemental positions:

Game 2, Position 1 after 31... cxd6

This was where we left off from our doubled pawns series. Black had just undoubled his pawns, but retains control over the queenside light squares, semi-open b-file and the two bishops. For someone like Magnus Carlsen, that is more than enough to secure a win. Unless you are playing against a staunch defender like Karjakin!

Black first centralizes his king, maintains pressure on the backward b2 pawn, before seeking to create a new weakness in his opponent's kingside. In this way he can utilize the principle of two weaknesses to make life more difficult for Black.

Game 2, Position 2 after 45. Nd1

After probing around for several moves, Black has obtained what he wanted: A kingside pawn majority. This gives White two weaknesses on opposite wings to take care of: The b2 pawn and a potential passed pawn on the other wing. Meanwhile, his own pawn majority is rendered useless by the c4 pawn, while his knight is restricted by the enemy's powerful bishop pair. Although material is equal, Black is effectively one pawn up.

With 45... Be6 it would effectively guarantee Carlsen free reign on the kingside. However, he erred with the pawn push 45... f4?, releasing the tension too early. While the intention was to tie down White's pieces to stopping the pawn while his own king invades via b3, it gave Karjakin an opportunity to build a fortress with Nf2, Bd4 and Kd2-Kc1, stopping Black's king from entering the queenside.

Game 2, Position 3 after 60... Kb3

In the closing shots of this tough battle, Black looks on the verge of breaking through on b3. But after 61. Kc1, White has set up his fortress. His king stops any encroachment by his opposing counterpart, while bishop and knight form a defensive blockade around the centre and kingside.

Amazingly, Carlsen has no way to make any further inroads into Karjakin's fortress! Although the game continued all the way till move 94, it was essentially drawn after 61. Kc1.

We show the full stages of the endgame in all its glory:


What can we learn from this game?

  1. Utilize the principle of two weaknesses; in this case White's pressure on the b2 pawn and the threats of his kingside pawn majority gave him a huge advantage
  2. Freezing an enemy pawn majority is a powerful endgame tool; combining it with the advance of your own majority on the opposite wing can be decisive
  3. Avoid closing up the position when you have a bishop against the enemy's knight

...

With the conclusion of Rounds 3 and 4, the score was still even. But with Carlsen so close to gaining the lead, it was definitely no series of boring draws. Truly great defense by Karjakin, and we shall look at more selected games in subsequent articles!

Links:
Part 1: http://nushsblackknights.blogspot.com/2016/12/world-chess-championship-2016.html
Part 2: http://nushsblackknights.blogspot.com/2016/12/world-chess-championship-2016_17.html
Part 3: http://nushsblackknights.blogspot.com/2017/01/world-chess-championship-2016.html
Part 4: http://nushsblackknights.blogspot.com/2017/01/world-chess-championship-2016_30.html

Sources:
https://www.youtube.com/watch?v=SeBfGhAhFQA
https://www.youtube.com/watch?v=tWfFx2Pa6zU
https://www.youtube.com/watch?v=ULaFA5eZnJA
https://www.youtube.com/watch?v=FuEEiLOTfs4
https://www.chess.com/news/view/scissors-can-t-beat-rock-in-world-champs-round-4-3294

Thursday, December 8, 2016

A story of doubled pawns: Part 3

In Part 2 we talked about the weaknesses of doubled pawns. But before we jump to conclusions and demonize all these poor fellas, let's first look at the other side of the mirror, and find out if they can offer anything that's helpful.

Today, we will see how doubled pawns can be used as an asset instead of a liability. To start off, we recap from Part 1 what advantages doubled pawns can offer:

  1. Opening of files. When doubled pawns are formed an adjacent file has to be opened, and this can be exploited by your rooks.
  2. Square control. By far the greatest strength of doubled pawns lies in defense, as they control more squares than regular pawn chains.

One rule of thumb when playing with doubled pawns is to avoid pushing them whenever possible. Advancing the forward pawn relinquishes control over vital squares and opens up holes around them. Unless pushing them helps to undouble the pawns, control even more important squares upfront, or whatever other reason, try not to do so.

To illustrate the defensive abilities of doubled pawns-- and why they should preferably stay at their posts-- we take a look at the following position:

Position 1: Doubled pawns on the kingside

The above diagram is similar to Position 4 from Part 2, only that we have dropped additional pawns on c2 and f7. As long as the doubled pawns remain in their positions, Black cannot advance his kingside pawns against them and hope for a breakthrough, or infiltrate with his king.

However, if White pushes the pawns with g4 and h3, then he creates weak spots in his position that the enemy king can use for himself.


Position 2: Weak spots among the doubled pawns

Let's play as Black and see if we can make any headway against the "weak" doubled pawns on the kingside. You might see both sides making a few suboptimal moves in the game below, but they are played so as to demonstrate the characteristics of doubled pawns:


Additional Square Control

From the first example we saw how doubled pawns play a defensive role by covering squares that would otherwise have been occupied by the enemy. If we extend this to actual gameplay, doubled pawns situated in front of a castled king can offer additional protection, with greater control over the squares in front of the monarch.

So long as the rear guys don't stab their friends in front by mistake

Another way to exploit this power occurs when said foot-soldiers are located close to the centre. It is not uncommon for grandmasters to accept doubled pawns so as to exert greater influence over the centre, as seen in the next example.

In the following game, Black gets doubled pawns on the c-file. Instead of becoming targets of attack, however, they end up being a great asset by increasing Black's presence in the centre. Radjabov used them to create an outpost on d4, gaining space and cramping up the opponent's position.

The following article provides more games, where the side with doubled pawns exploits them to exert central dominance. A true testimony to Tarrasch's teachings on centre control!

"Son, I am proud"


Opening of files

When a pawn captures onto an adjacent file and forms doubled pawns, the original file is inevitably opened up. This is another valuable resource that can be used by friendly rooks.

The concept of occupying such an open file occurs in a few openings, such as the following variation of the Caro-Kann: 1. e4 c6 2. d4 d5 3. Nd2 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. Nf3 e6 7. Ne5!? Nd7 8. Nxg6 hxg6 (D)

Position 3: Doubled pawns with an open file for the rook

Black has doubled pawns, but has a beautiful half-open h-file for his rook. His plan is to castle queenside and bring his pieces over for a kingside attack, using the h-file as a springboard for the assault. The following game between two anonymous players is a good illustration of this:

One striking example of doubled pawns and the adjacent open file comes from Game 4 of the recently concluded World Championship Match. Carlsen had doubled isolated pawns on the queenside, but was able to take advantage of the half-open b-file -- and his light-square dominance-- to pressurize the opponent's position. This gave Carlsen serious winning chances throughout the game, and it was only after grim defense by Karjakin that the game was finally drawn.

We will examine this game in greater detail in our WCC 2016 series.


Other forms of compensation

This is a more generalized idea of the previous part. Apart from the adjacent open file, doubled pawns can be accepted if they come with some sort of compensation. In openings like the Ruy Lopez and Nimzo-Indian, one side gets a damaged pawn structure, but acquires the bishop pair as compensation. It boils down to whether he can open up the position to utilize his advantages, yet at the same time take the focus of battle away from his doubled pawns.

Our final game is a good showcase of how the two bishops balance out the apparent weakness of the doubled pawns:

...

To wrap up, doubled pawns are not always the devil of a game. They can offer valuable help by controlling extra squares, opening up files, or create other forms of compensation. So don't go around saying that doubled pawns are always bad... such hearsay is is reserved only for beginners!

So far we have focused mainly on the effects of doubled pawns in the opening and middlegame. In Part 4, we will look at how they can affect the endgame as well.

To be continued...

Links:
Part 1: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-1.html
Part 2: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-2.html
Part 3: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-3.html
Part 4: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-4.html
Part 5: http://nushsblackknights.blogspot.com/2017/01/a-story-of-doubled-pawns-part-5.html
Sources:
"Modern Chess Strategy" by Ludek Pachman
https://www.youtube.com/watch?v=1rTMfayZatI
http://www.thechessworld.com/learn-chess/2-middle-game/526-doubled-pawns-weakness-or-strength-part-2
http://300spartanwarriors.blogspot.sg/2016/06/classical-greece-and-ancient-greek_93.html

Thursday, December 1, 2016

World Chess Championship 2016 Highlights: Part 1

Yesterday the chess world concluded one of its most historic events of the year: The World Chess Championship 2016. This year saw Carlsen faced with his biggest challenge yet, for Karjakin was able to hold out throughout the classical games and even achieve a one-point lead (briefly) in Game 8. The results were finally decided in hair-raising tiebreakers where the Norwegian routed his opponent 3-1.

WCC 2016, Carlsen's toughest championship test

With so many instructive games in the past two weeks, I cannot resist going through some of them. Hence, I will dedicate a new series of articles to analysis of selected WCC 2016 games. Don't worry though, I haven't forgotten about wrapping up the doubled pawns series I started last month!

What better way to kick off than with one of the match-deciding games from the tiebreakers!

Karjakin, Sergei vs Carlsen, Magnus
World Chess Championship 2016 Tiebreakers Round 3

In the previous game, Karjakin escaped with a miraculous draw after sacrificing several pieces and pawns to force a stalemate. Going into the final two rounds, we will see whether he can continue his unbreakable spirit, or whether Magnus will finally wear him out.

1. e4 e5
2. Nf3 Nc6
3. Bb5 a6
4. Ba4 Nf6
5. O-O Be7
6. d3 b5
7. Bb3 d6
8. Nc3 O-O
9. a3 Na5
10. Ba2 Be6
11. b4 Nc6
12. Nd5

You may be wondering whether White could simply wreck Black's pawn structure with 12. Bxe6 fxe6. Yes, White does get doubled pawns, but they are not easily attacked in this closed position. In fact, they may even help Black by controlling more squares in the centre and opening up the f-file for his rook.

12... Nd4
13. Ng5 Bxd5

While damaging White's pawn structure Black has to give up his bishop pair, but this isn't particularly alarming since the two bishops cannot fully unleash their power in this closed position.

14. exd5 (D)

Position after 14. exd5

Not 14. Bxd5? giving up the bishop pair for nothing, and also losing a piece after Nxd5

14... Nd7

Making room for an f5 push, expanding on the kingside while keeping the centre closed. 14... c6 comes into consideration, giving Black's pawn centre some free reign. However, he wouldn't want to undouble White's pawns and open the centre for the bishop pair, so this plan is cast aside in favour of the main line.

15. Ne4 f5
16. Nd2 f4

Things are starting to go Black's way. While White has the bishop pair, one is blockaded by the enemy pawns, while the other babysits a friendly pawn on d5. This is why Carlsen chooses to keep the centre closed.

17. c3

Otherwise 17... f3 follows.

17... Nf5
18. Ne4 Qe8

Bringing reinforcements to the kingside.

19. Bb3

Since Karjakin can't do anything about White's plans for now, he tries to find counterplay on the other wing. Here, the aim is to push a4 and (hopefully) get the light-squared bishop onto a better diagonal.

19... Qg6
20. f3!? (D)

Position after 20. f3

A natural and solid looking move, preparing 21. Ra2/Rf2 as a response to 20... Nh4. But some consider this questionable: White's queen is cut off from interfering, and the e3 square becomes a tempting outpost for the enemy. For now only the bishop on f1 stands guard over it.

20... Bh4

White needs to be watchful of a potential bishop sacrifice on g3, which would open up the h-file and bring the pawn onto g3, covering the White king's escape squares. This is a common attacking motif against an undefended kingside.

21. a4 Nf6
22. Qe2 a5!

Magnus creates problems for his opponent, who was starting to run into time trouble.

23. axb5?

The wrong choice made under time pressure. This lets Black exchange on d4, weakening e3 and giving White multiple pawn weaknesses. After 23. bxa5 Rxa5 24. Ra2! bxa4 25. Rxa4 Rxa4 26. Bxa4 White has achieved what he wanted: Get some space for his bishops. While Black still has strong pressure on the kingside, at least White can give him some problems on the opposite wing.

23... axb4
24. Bd2 (D)

Position after 24. Bd2

Black chooses not to take the extra material, since he has a hanging rook and a vulnerable d4 square to take care of.

24. Rxa8 Rxa8 25. cxb4? Nd4! The extra material is worth nothing since it comes in the form of isolated doubled pawns.

24... bxc3
25. Bxc3 Ne3

With the bishop no longer covering e3 Black can brazenly step in. Karjakin's position is becoming very cramped, and the fact that he is down on time isn't helping at all.

26. Rfc1!

Setting up a trap. The key is that Black's king is under indirect fire by the light-squared bishop, which means the d5 pawn cannot be taken straightaway.

26... Rxa1

There are many ways Black could have gone wrong here:

  1. 26... Nfxd5? 27. Qxe3! fxe3 28. Bxd5+ Gaining a rook, bishop and pawn for the queen. But what is more important is that Black's attacking strength is severly reduced, and the e3 pawn will fall very soon.
  2. 26... Nexd5? 27. Nxf6+ is even worse for Black, for the pin ensures he remains a piece down after the exchanges.
  3. Finally, 26... Rab8? falls prey to a discovered attack: 27. Bxe5! dxe5 28. d6+ $1 Kh8 29. dxc7 Rbc8 30. Nd6 At the cost of his bishop White gets a powerful passed pawn.

27. Rxa1 Qe8

It seems weird to retreat from the kingside when you were putting so much pressure on it. But flexibility is a virtue of war, and here Black switches sights to attack the queenside weaknesses.

28. Bc4 Kh8

Stepping away from the line of fire. Now Black threatens to capture on d5.

29. Nxf6 Bxf6
30. Ra3

30. Bd2 with hopes of getting rid of the e3 knight fails after 30... e4! 31. Ra3 exf3 32. Qxf3 opening up the e-file as an invasion point for Black's queen. There is no way White can trade on e3 now, otherwise a passed pawn is born.

Black has the edge with his strong knight, and his position has less vulnerable points than White's. But White still holds the fragile line with his bishop pair. Can the world champion find a breakthrough here?

30... e4!

Sacrificing a pawn to gain entry.

31. dxe4

White is very happy to undouble his pawns, so why not?

31... Bxc3
32. Rxc3 Qe5! (D)

Position after 32... Qe5

The point of 30... e4, to clear the d5 square as a staging point for the invasion. Black's dark-square dominance is indisputable.

33. Rc1 Ra8
34. h3 h6
35. Kh2 Qd4
36. Qe1?

Cold-blooded engines would not hesitate to play the counter-intuitive 36. Ba2 temporarily halting Black's invasion of the 1st rank, but for a human to find this with less than 5 minutes on his clock would be too much to ask.

36... Qb2

Threatening a mate in one; the next move is forced.

37. Bf1 Ra2
38. Rxc7??

With seconds left on his clock, Karjakin makes his final error. But the endgame was already extremely difficult to defend.

38. Rb1 was the only defense; 38... Qf6 39. Be2 Black still maintains a huge advantage but has no immediate win.

38... Ra1 (D)
0-1

Position after 38... Ra1

White must give up the queen or face ... Nxf1+/Qxg2#.

With this win Carlsen gains a huge morale victory; he only needs a draw in his next game to defend his title!

Links:
Part 1: http://nushsblackknights.blogspot.com/2016/12/world-chess-championship-2016.html
Part 2: http://nushsblackknights.blogspot.com/2016/12/world-chess-championship-2016_17.html
Part 3: http://nushsblackknights.blogspot.com/2017/01/world-chess-championship-2016.html
Part 4: http://nushsblackknights.blogspot.com/2017/01/world-chess-championship-2016_30.html
Sources:
https://www.chess.com/news/view/carlsen-wins-rapid-playoff-defends-world-championship-7236
https://www.youtube.com/watch?v=eclStFntWGE
https://www.youtube.com/watch?v=VWWwfYNzrfs
https://www.youtube.com/watch?v=85RTfoI97oQ

Tuesday, November 29, 2016

Fortress: National Age Groups 2016 Round 4

As promised, here is the analysis of the game which we have discussed. I nearly died trying to figure out what both players were thinking; while there were some really excellent plans, there was also no shortage of dubious moves. But since I wasn't the one playing I won't be able to judge too much, so I will just write whatever I can infer from the moves.

Black's vigorous attack, triggered by White's mess-up in the opening, turned into a botch-up of his own. White's staunch defense allowed him to build a fortress and equalize in the endgame. It is definitely no boring draw, with so many missed opportunities to break down the defenses!

Or missed footings while trying to storm the fortress

I have hidden the identities of the players for their privacy:

1. e4 c5
2. Nc3 e6
3. Nf3 Nc6
4. Bb5 Nf6
5. d4?

Premature. It was not wise to open the position so early when White's king is still in the centre. A simple 5. O-O would have solved these problems.

5... cxd4
6. Nxd4 Bb4
7. f3?

It was not too late to admit the mistake: 7. Nxc6 bxc6 8. Bd3 (While retreating the bishop is a painful decision, at least White relives the tension on his centre.) 8... Qa5 9. Bd2

7... Qa5!

Now all 3 of White's developed pieces are under attack. To save his position he has to give up a pawn.

8. Nxc6

Any other form of protection doesn't work: 8. Qd3? Nxd4 9. Qxd4 Bxc3+ 10. Qxc3 Qxb5 loses a piece.

8... bxc6
9. Bd3 Bxc3+
10. bxc3 Qxc3+
11. Bd2 Qd4
12. Rb1 O-O
13. Rb4

White does not have all the fight squeezed out of him yet! While winning material Black allowed his lady to go for a long walk, leaving her vulnerable.

13... Qe5
14. f4

14. O-O followed by f4 was good too.

14... Qc7
15. g4!?

Since most of White's pieces are already positioned towards the kingside, it is natural to plan for an attack on that wing. But this is a risky maneuver; White's king is still exposed, and will crumble quickly in the face of a counterattack...

15... c5 (D)

Position after 15... c5

Which Black is quick to deliver.

16. g5?

The rook sacrifice, intended to tear apart Black's kingside, can be easily refuted.

16... Ne8?


Only that Black believes his opponent... and his own paranoid beliefs!

16... cxb4 17. gxf6 g6 ({Edit: Ben has pointed out that} 17... gxf6 $4 18. Qg4+ Kh8 19. Rg1 is unstoppable mate; I must be blind for not seeing this!) 18. Qg4 Kh8

This simple move allows for ... Rg8 discouraging White from attempting Qh6-Qg7#. Black can now consolidate his extra material, and continue the play against White's exposed king.

17. Rb1 c4
18. Bf1?

Turning the clock back on development.

18. Be2 was less cringe-worthy; 18... c3 (18... Bb7 19. Bf3) 19. Be3 Rb8 20. O-O White still has two main concerns to address: Strengthen his central pawns, and win back the weak pawn on c3. But his king is definitely much safer than in the main line. So for example: 21... Nd6 (Black places pressure on e4 and f4.) 21. Rxb8 (otherwise ... Rb2 follows.) 21... Qxb8 22. Bf3 Bb7 23. Qd3 f5 24. Bc5 $1 fxe4 25. Qxd6 Qxd6 26. Bxd6 exf3 27. Bxf8 Kxf8 with a rook vs bishop + 2 pawns endgame.

18... c3
19. Bc1

The only explanations I can find to choose this over 19. Be3 is that White wants some degree of control over b2, and retain the possibility of playing Ba3. It is dubious whether these reasons are worth weakening the coordination between White's pieces.

19... Rb8
20. Rxb8 Qxb8
21. Be3 Bb7
22. Bg2 Bc6
23. h4?

By now, it is too risky to leave your king behind and go all out; Black's forces on the queenside are becoming too strong. It was still possible to save the day with 23. O-O Nd6 24. Qd4 and Black cannot play 25. Qb2 without first addressing the awkward position of his knight.

23... Qb4!

Black's next few moves are basically forced.

24. Bd4 Nd6
25. Qd3 Nb5
26. Be3 Qb1+
27. Kf2 Qxa2 (D)

Position after 27... Qxa2

Black has complete dominance of the queenside, and can safely escort his outside passed pawn to the queening square. Surely he can't mess this up!

28. e5 Qb2
29. Bxc6!

Trading pieces to relieve pressure and damage the adversary's pawn structure. But it might not be enough to save White, provided Black knows what he's doing.

29... dxc6
30. Rc1 a5?

Too eager. The pawn needed sufficient support before it could advance. Black is quick to punish this...

30... Qb4 securing the area first, giving the pawn a safe path to the promised land.

31. Qc4! (D)

Position after 31. Qc4

Thanks to the bishop exchange, White finds counterplay by attacking the weakness on c6, at the same time holding the line on a4.

31... Na3
32. Qa4

Just look at all the tension around c2, c4 and a5! To break this stalemate Black brings in reinforcements.

32... Rb8
33. h5

33. Qxa5? Nxc2 followed by Nxe3 and c2 upon which White can resign.

33... Rc8?

Too passive. 33... Rb5! followed by Qb4 forces White to trade off a critical queenside defender, clearing the way for the a-pawn.

34. Kf3 Qb4

The only way to get rid of the pesky defender. However, removing the queens from the board gives White a much needed reprieve, giving him time to set up a queenside fortress.

35. Qxb4 axb4
36. Bc5! Rb8
37. Bd6

Keeping watch over b4, getting ready to hit a3 should Black push b3, and keeping the Black king trapped by taking away the f8 square. On top of that, an outpost with no pawns to chase it away. You can't ask for a better square for this bishop!

37.. Rb5
38. Ra1!

Pinning the knight, since Ra8+ leads to mate on the next move.

38... c5
39. Ke2 Ra5
40. Kd1 g6
41. h6 (D)

Postion after 41. h6

Black's once vigorous advance has fizzled out, with the enemy erecting a fortress in the centre and queenside. None of his pieces can move without hanging another pawn or piece, and his king is fenced in on the 8th rank. But White's job isn't easy either; his opponent's pieces and pawns are also ideally placed to prevent White's king from making any form of intrusion. By now both sides would be running low on time; in their eagerness to break the deadlock, they mark the endgame with multiple inaccuracies.

41... f5

Returning material to get the king out.

42. exf6 Kf7
43. Kc1 Rb5
44. Kd1 e5?

This sacrifice doesn't do much other than weaken the g5 pawn. In fact, it makes White's kingside stronger by giving him another passed pawn to play with.

45. fxe5 b3
46. cxb3 c2+?

46... Rxb3 47. Rc1 (47. Bxc5? is very tempting but after 47... Rb1+ 48. Rxb1 Nxb1 49. Kc2 Nd2 followed by Ne4 or Nf3 upon which White's pawns will fall like bowling pins.) 47... c2+ 48. Kd2 Rb5 with neither side being able to make progress.

47. Kc1? (D)

Position after 47. Kc1

Missing an opportunity to turn the tables. 47. Kd2 Rxb3 all seems lost after 48... Rb1 but White has a powerful resource 48. Re1! proving Black's mistake on the 44th move by threatening to advance the pawns. 48... Ke6 49. Bxc5 and suddenly White has the better endgame!

47... Rxb3

White must give up his rook to stop the threat of 48... Rb1+

48. Rxa3 Rxa3
49. Kxc2 Ra4?

It was important to keep the rook active. 49... Rg3! was better, keeping White's king further away from the action. 50. Bxc5 Rxg5 51. Bd6 Rg3 52. Kd2 Rh3 53. Ke2 Rxh6 54. Ke3 Rh4

By keeping the rook on the 4th rank the White monarch is unable to support his own pawns, while Black can advance his own pawns to victory.

50. Kc3 Rg4
51. Bxc5 Rxg5
52. Kd4

With the White king joining the battle the outcome is less clear.

52... Ke6
53. Bd6 Rh5
54. Kc5 Rxh6
55. Kc6 Rh5?

Now White can use his passed pawns to save himself.

Black still had one last road to victory: 55... g5! 56. f7 Kxf7 57. Kd7 g4 is game over.

56. f7! Kxf7
57. Kd7

To stop the remaining passed pawn Black has no choice but to sacrifice his rook. The game is essentially drawn from here onwards.

57... Rh1
58. e6+ Kg8
59. e7 Re1
60. e8=Q+ Rxe8
61. Kxe8 g5?

Black's final mistake in this crazy game is to advance the pawns without king support, although Deep Fritz analysis shows that it would still be a draw otherwise.

61... Kg7 62. Be7 Kh6 (62... h6 63. Bf8+ Kf6 64. Bxh6) 63. Kf7 Kh5 64. Kg7 h6 65. Kf6

62. Be5

King and bishop work together to fence in the enemy king; the pawns are devoid of any support.

62... h5
63. Ke7 g4
64. Kf6 h4
65. Kg5 g3
66. Kxh4 g2
67. Bd4 (D)
1/2-1/2

Position after 67. Bd4

Sources:
http://photobucket.com/images/facepalm%20gif
https://www.youtube.com/watch?v=FuEEiLOTfs4

Friday, November 25, 2016

Thanksgiving Tactical Presents 2016

Not that we celebrate Thanksgiving here, but I just want to find a reason to give more puzzles:






Have fun!

Image from imgflip.com

Tuesday, November 22, 2016

A story of doubled pawns: Part 2

In Part 1, we learned a simple technique to get rid of doubled pawns: Blockade, exchange, and pile attacks on them. For isolated doubled pawns, it is straightforward since they have little protection. For non-isolated cases, an assault would be longer and more difficult.

Let us first recap the problems that doubled pawns face:

  1. Limited mobility. Since the second pawn cannot advance unless the first pawn moves, doubled pawns cannot advance quickly.
  2. Vulnerable. The front pawn is prone to attack, as it cannot be defended from behind by a rook. This problem is further aggravated in the case of isolated doubled pawns, as we see in Position 2.
  3. Weak squares. The square in front of the doubled pawns is usually weak and easily occupied by an enemy piece. While advancing an adjacent pawn helps protect the square, it opens up other weak squares in the vicinity.

We have touched on Point 2 in our earlier article, where assaulting doubled pawns leads to their capture and gaining of material advantage. But in most games, it is not just about laying siege for the sake of finishing them off. Very often, these intriguing foot-soldiers form part of a broader picture, where they are combined with other weaknesses across the board. This important idea is called the principle of two weaknesses.


Principle of two weaknesses

If you already know what this phrase means, give yourself a pat on the back. For the uninitiated, the principle of two weaknesses is the concept of assaulting two or more weak points in the enemy's position. If the opponent has a single weak spot and you lay siege to it, he can simply rush all his defenders there and hold out till Mexico pays for Trump's Wall.

"I'm very good at this, it's called construction, there could be some fencing"

But if your opponent has multiple weaknesses, you can alternate attacks on them. As the defending side usually has less space to maneuver his pieces, he would find it more difficult to respond to threats from different directions, and will eventually crumble with enough pressure.

This means that if you face a set of doubled pawns, you don't always have to keep hitting them in the hope of overrunning the position (as we saw in Part 1); if you can to find another hole in the enemy camp, you can attack it too while maintaining pressure on the doubled pawns. We illustrate this with a diagram:


Botvinnik - Reshevsky
1948 World Championship Round 14
Position 1: Weaknesses on opposite wings

Black attacks the doubled pawns on the c-file, but White is holding out. Instead of focusing all efforts on a brick wall, Black can probe the other wing for another weakness. In this case, White's f4 pawn is a potential target that can be accessed via Ne8-Ng7-Nh6.

Thus, while hitting this new weakness and keeping watch on the doubled pawns, Black ties down White's pieces and prevents them from responding quickly to the new threat.

"For should the enemy strengthen his (front), he will weaken his rear; should he strengthen his rear, he will weaken his (front), should he strengthen his left, he will weaken his right; should he strengthen his right, he will weaken his left. If he sends reinforcements everywhere, he will everywhere be weak."
-- Sun Tzu

The full game can be viewed below, analyzed by Ludek Pachman in "Modern Chess Strategy". Note how Black first deprives White of any potential counterplay, before using the principle of two weaknesses to place pressure on the doubled pawns.


Attacking weak squares

Doubled pawns can be weak, and so are the squares around them. Rather than trying to explain what this means I think it is best to look at a couple more diagrams:

Position 2: The c5 square is weak

Position 2 speaks for itself; Black could sink a piece onto c5 since the square is poorly defended. But couldn't White simply push b6 to defend the square? Let's see what happens:

Position 3: After advancing, the c6 pawn becomes weak

So c5 is secured, but now the c6 pawn is hanging! Black can attack the new weakness with impunity. And if Black pushes c5 again to protect the pawn then c4 becomes weak, and if b5 is played then c5 becomes weak, and so on...

The following game illustrates how this concept of occupying weak squares is played out. Once again White uses the principle of two weaknesses, with Black's doubled pawns and weak kingside pawns playing the victim.

The game has been annotated in detail in the following article from TheChessWorld, thus I will be adopting most of the annotations here.


Using the pawn majority

Another way to play against doubled pawns is not to attack them directly, but exploit their limited mobility. In the position below, White cannot hope to exploit his kingside pawn majority, as the advance of his doubled pawns is beset by difficulties. On the other hand, Black can look towards creating a passed pawn on the other wing where his own majority is unhindered. White is effectively a pawn down in the endgame.

Position 4: White's kingside majority is not effective

This is another common strategy when dealing with doubled pawns. By blocking the advance of the doubled pawns, the attacker can freeze the enemy's pawn majority and render them useless. He will then advance his own majority on the other wing to win the endgame.

Such plans are part of White's ideas in the Ruy Lopez Exchange, where Black gets doubled pawns on the c-file:

Position 5: Doubled pawns in the Ruy Lopez

White would be very happy to simplify to an endgame, where he can blockade the queenside before advancing his own kingside majority to victory. The next game is a classic example of this.


...

To recap, there are 3 main weaknesses of doubled pawns: They are vulnerable, have weak squares, and are difficult to advance. We have discussed a few methods to play against them:

  1. Blockade and hit em' with everything you've got in order to win material.
  2. Same as Step 1, except to add in the principle of two weaknesses to wear down the opponent.
  3. Use the weak squares around them as outposts for your pieces.
  4. Limit their movement and advance your pawn majority on the other wing to create a passed pawn.

In all cases, it is generally a good idea to exchange into the endgame, where the vulnerability of the doubled pawns become more apparent.

But is all hope lost when you get a pair of doubled pawns? Perhaps yes... but perhaps not! In Part 3, we will discuss how they can offer advantages that may help you turn the tables on your opponent.

To be continued...

Links:
Part 1: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-1.html
Part 2: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-2.html
Part 3: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-3.html
Part 4: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-4.html
Part 5: http://nushsblackknights.blogspot.com/2017/01/a-story-of-doubled-pawns-part-5.html
Sources:
"Modern Chess Strategy" by Ludek Pachman
"Understanding Pawn Play in Chess" by Drazan Marovic
https://www.chess.com/article/view/doubled-pawns
https://www.ichess.net/2015/03/20/doubled-pawns-advantages-disadvantages/
http://www.fourwinds10.net/siterun_data/history/american/news.php?q=1457372701

Sunday, November 13, 2016

A story of doubled pawns: Part 1

In many games a piece protected by a pawn is frequently exchanged, resulting in two pawns residing on the same file. This phenomenon is what we know as doubled pawns

Early in their chess education, every beginner is taught that doubled pawns are weak. They are unable to protect each other, and cannot advance as quickly as other pawns. But like isolated pawns, doubled pawns are misunderstood as being bad all the time. If handled wisely, they could turn out to offer certain advantages.

Understanding when doubled pawns are good or bad is an important factor in chess strategy. Many openings, such as the Ruy Lopez or Nimzo-Indian, feature one side accepting doubled pawns in exchange for some other advantage. In this series, we will attempt to uncover the story behind doubled pawns, and how to play with or against them.

Position 1: Doubled pawns in the Nimzo-Indian


The basic outline

The pros and cons of doubled pawns can be listed as follows:

Disadvantages:
  1. Limited mobility. Since the second pawn cannot advance unless the first pawn moves, doubled pawns cannot advance quickly.
  2. Vulnerable. The front pawn is prone to attack, as it cannot be defended from behind by a rook. This problem is further aggravated in the case of isolated doubled pawns, as we see in Position 2.
  3. Weak squares. The square in front of the doubled pawns is usually weak and easily occupied by an enemy piece. While advancing an adjacent pawn helps protect the square, it opens up other weak squares in the vicinity.

Position 2: The front pawn cannot be defended from behind


Advantages:

  1. Opening of files. When doubled pawns are formed an adjacent file has to be opened, and this can be exploited by your rooks.
  2. Defense. By far the greatest strength of doubled pawns lies in defense, as they control more squares than regular pawn chains. We investigate this in closer detail in subsequent articles.

This can be seen in Position 3, a typical position from the Ruy Lopez where White damages Black's pawn structure by capturing on c6. However, Black's doubled pawns offer some perks of their own: Opening up the d-file, and controlling additional squares on the queenside. So long as the pawns don't advance, Black's queenside remains solid.

Position 3: Doubled pawns in the Ruy Lopez


In Part 1, we will focus on Isolated Doubled Pawns.


Isolated doubled pawns

Isolated doubled pawns are almost always weak, as they combine weaknesses of both isolated and doubled pawns (well, duh). And unlike normal isolated pawns which can still be pushed to create passed pawns, it is not so easy with isolated doubled pawns due to their lack of mobility.

To deal with these structures, we treat them as large versions of isolated pawns. Blockade the front pawn, before trading pieces to make the weakness more significant. Rooks are particularly deadly against them, as their friendly rooks are unable to provide effective support from behind (since the rear pawn gets in the way, and you can't exactly use friendly fire to get rid of him).

Or we will invoke your sense of guilt and patriotism, mixed with a dash of vodka

The following game is a simple example on how to play against isolated doubled pawns:

Easy, wasn't it? All you need to do is blockade the damn thing, trade pieces, and pile attacks on it...

It won't be so straightforward when it comes to non-isolated doubled pawns, though! That will be covered in Part 2.

To be continued...

Part 1: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-1.html
Part 2: http://nushsblackknights.blogspot.com/2016/11/a-story-of-doubled-pawns-part-2.html
Part 3: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-3.html
Part 4: http://nushsblackknights.blogspot.com/2016/12/a-story-of-doubled-pawns-part-4.html
Part 5: http://nushsblackknights.blogspot.com/2017/01/a-story-of-doubled-pawns-part-5.html
Sources:
"Modern Chess Strategy" by Ludek Pachman
"Understanding Pawn Play in Chess" by Drazan Marovic
https://www.chess.com/article/view/doubled-pawns
https://www.ichess.net/2015/03/20/doubled-pawns-advantages-disadvantages/
https://www.youtube.com/watch?v=62UjBxSlurg

Thursday, November 10, 2016

Chess Camp Curiosities (2016 edition)

Good afternoon, my friends. Firstly, I will like to thank y'all for the memorable day yesterday. For that brief afternoon I was there, we forgot about the hate, bullying and bigotry that was tearing through the outside world. Instead, we spent our time enjoying the one thing we had in common: Chess. You guys have showed me that love truly trumps hate (*cough cough*).

Image from Student Problems on Facebook

But let's get back to business. As promised, here is the analysis from Game 3 of our final activity. I have tried my best to provide comments while keeping a straight face.

Black Knights vs Anonymous
Black Knights Camp 2016 (Day 3)

1. e4 c5
2. Nc3 Nc6
3. Bb5 d6
4. Nf3 g6
5. Bxc6+ bxc6

White gives up his bishop pair to give Black doubled pawns, a common strategy in many openings. The question is, are the doubled pawns a major weakness in this position? For now they control vital squares on the queenside, open the b-file, and allow the light-squared bishop access to a6; the only vulnerability being the weak square on c4.

6. d4

The threat is to take on c5. After the exchange, Black's isolated doubled pawns will become vulnerable to attack.

6... Ba6?

While well-intended (developing the bishop and disrupting White's chances of kingside castling), Black overlooks the earlier threat. 6... cxd4 had to be played, 7. Nxd4 c5 8. Nf3 Ba6 gaining tempo for Black.

7. Be3?

But White returns the favour by not being aware of his own potential. Both sides spend the next few moves seemingly unaware of the threat. 7. dxc5 dxc5 8. Be3 was better

7... Bg7
8. Qd2 Rb8
9. O-O-O

Out of the frying pan, into the fire!

9... Qb6
10. Na4 Qb5
11. b3 (D)

Position after 11. b3

Let us analyze the position. White is far ahead in development: His immediate threat is dxc4, opening up the d-file for his heavy pieces to attack Black's exposed king. Yet he needs to be careful of Black's b-file control, and the opening of the long diagonal for the enemy dark-squared bishop should he capture on c5.

11... e6?!

Better was 11... cxd4 12. Bxd4 Nf6... You get the idea. After ... 0-0 Black will have a very comfortable position.

12. dxc5 d5

The purpose of 11... e6. But this wasn't the soundest plan.

13. Bd4?

Missing an opportunity to gain the advantage, as I will explain in the variations:

  • 13. exd5? is tempting; 13... cxd6 gives White a passed pawn, while 13... exd6 further exposes Black's king and creates a weakness on c6. But Black has a cunning way to slip out: Qxa4! 14. bxa4 Bb2+ 15. Kb1 Bg7+ with a draw by perpetual.
  • Fritz suggested the intermezzo 13. Nd4! Qb7 upon which White can safely take on c5 without fear of the enemy queen interfering. 14. exd5: Now, Black is in trouble whichever pawn he recaptures with.

13... Bh6
14. Be3

Once again, the silicon monster Deep Fritz conjures up a winning variation for White: 14. Ng5! f6 15. f4! upon which we see that Black's rook is pretty much useless, since the adjacent knight cannot move out of the way without compromising kingside safety. But admittedly, spotting the winning combination would be no mean feat!

14... Bxe3
15. fxe3 (D)

Position after 15. fxe3

At first glance this looks ludicrous... why would one accept doubled pawns so willingly when it was perfectly alright to recapture with the queen? But by leaving the queen on d2, it allows White to retain control of the d-file, threatening the exposed Black king as well as the possibility of Qd4 securing the long diagonal.

15... Nf6

Otherwise 16. exd5 is detrimental to Black's position.

16. Qd4 Ke7
17. Nc3 Qb7
18. e5?

Locking up the centre only makes the Black king safer. I still feel it was better to undouble the pawns asap: 18. exd5 Nxd5 19. Nxd5+ cxd5 20. Ne5 with the passed pawn playing to White's advantage. 21. c4 opening the d-file could follow next.

18... Nd7
19. Rd2

Since White can't make progress in the centre, he turns to the semi-open f-file.

19... Qb4

Attempting to trade pieces to relieve the pressure on the king.

20. Rf2 Nxc5
21. Qxb4 Rxb4
22. Nd4 (D)

Position after 22. Nd4

Better was 22. Ng5! focusing on the kingside; Black cannot hope to defend both f7 and h7 at the same time: 22... Rf8 23. Nxh7

22... Bb7
23. Rhf1 Rf8
24. a3 Rb6
25. Nf3

Finally bringing the knight back to hit f7, but is it too late?

25... f5
26. exf6+ Rxf6
27. Ng5 Rxf2

Black successfully simplifies and reduces the strength of the attack.

28. Rxf2 Rxb3?

Attempting a Cheap tactic, but White can step over it easily.

29. cxb3?

Except that White doesn't!

29. Rf7+! This powerful intermezzo is what both sides missed. 29... Ke8 30. cxb3 Black can resign.

29... Nd3+!
30. Kd2 Nxf2
31. Nxh7 Ng4 (D)

Position after 31... Ng4

Black has equalized comfortably in the endgame, although his pawn structure is still slightly inferior.

32. h3 Nf6
33. Ng5

The correct decision. 33. Nxf6 Kxf6 helps Black centralize his king.

33... Ba6
34. Na4 Bf1
35. g4 Ne4+?

The final mistake of this crazy game. This trade benefits Black in no way, and only harms his pawn structure by creating weak, isolated doubled pawns.

36. Nxe4 dxe4
37. h4 Kf6
38. Nc5 Bg2
39. Nd7+ Kf7
40. Ne5+ (D)
1-0

Position after 40. Ne5

Black lost on time, but the endgame was already better for White.

I understand that this was not the most legit of games, played under non-tournament conditions with much discussion and disagreement. My hope is that our playing skills in the tournament hall will not be as comical as what we have just seen!

Sources:
https://www.facebook.com/StudentProblems/?fref=ts