Tuesday, January 20, 2015

Exploiting a pawn structure weakness: Kickoff 2015 Chess Tournament Round 2

Last week's tournament went poorly for me, but nevertheless there were several instructive games to analyze. So today, we will look the game from Round 2. Here, you will see how weaknesses in the pawn structure can be exploited to attain a lasting strategic advantage.

Checkerboard 5 vs Opponent
Kickoff 2015 Chess Tournament (Round 2)



1. c4 c5
2. Nc3 e6
3. g3 d5
4. cxd5 exd5
5. e3 Nc6
6. d4

Otherwise Black will push d4, leaving me with a backward e3 pawn after the exchange.

6... cxd4
7. exd4 Nf6
8. Bg2 h6
9. Be3 Bf5
10. Nge2 Qd7 (D)

Position after 10... Qd7

11. O-O

For a moment I toyed with the idea of trying to win the d5 pawn, but decided to complete my development first. Later on I looked at the line 11. Nf4 Rd8 12. Nfxd5 (12. O-O Be4 13. Bh3 Bf5 14. Bg2 Be4 15. Bh3 Bf5 16. Bg2 will be a really peculiar draw) 12... Nxd5 13. Nxd5 (D)

Position after 13. Nxd5

For a while it would seem White has the advantage, but after 13... Nb4! 14. Nxb4 Bxb4+ 15. Kf1 (15. Bd2?? Qxd4 16. Bxb4 Qxb4+ loses the Queen) 15... O-O White's awkward king position may prove more significant than his extra pawn.

Returning to the position after 11. O-O:

11... Bh3
12. Nf4

In all honesty I don't see much difference between 12. Nf4 and the variation 12. Bxh3 Qxh3 13. Nf4 Qf5 so I wonder why I spent so long on this move.

12... Bxg2
13. Kxg2 Bb4
14. Qb3 Bxc3 (D)

Position after 14... Bxc3

15. bxc3?!

During the game I was uncomfortable with the thought of an isolated central pawn in the endgame; however, by doing so I inadvertently created a backward pawn on c3. This gave me significant problems as you will see later on.

15. Qxc3 would have been the better option; O-O 16. Rac1 Rfe8 (Play will revolve around the two central pawns and their adjacent squares) 17. Qc5 Rac8 18. Qb5 Ne7 19. Qxd7 Nxd7 20. Rfd1 Nf6 21. Rc5 Rxc5 22. dxc5 (D)

Position after 22. dxc5

Black may have a passed pawn here, but White is able to blockade it: 22... Rd8 23. Ne2 Nf5 24. Nd4! planning for a long term restraint of the d4 square.

Returning to the position after 15. bxc3:

15... O-O
16. Rad1?! Rac8

We see Black's long term plan here: To occupy c4 and pressurize the c3 pawn.

17. Rc1

Wasting a move.

17... b6
18. Qb5 Ne7
19. Qxd7 Nxd7
20. Rc2 Nf6
21. a4?

Better was 21. Rb1, preparing 22. Rb4 if Black plays 21... Rc4

21... Rc4! (D)

Position after 21... Rc4!

Now I have two weak pawns to defend.

22. Ra1 Rfc8
23. Ra3 Ne4

Slowly adding on to the pressure. Black's pieces are dominating, while White's are tied down to defending their weak pawns.

24. Ne2 g5
25. g4

Black is in control of the Queenside; I have to find counterplay on the other wing.

25... Nc6
26. Rc1

Else Black will play 26... Nb4 followed by 27... Nd3

26... Ne7
27. f3 Nd6
28. Kg3 (D)
0-1

Position after 28. Kg3

Here I stopped recording, but eventually blundered in time trouble and lost. Nevertheless, you can see my position here is already worse off.

So what can we learn from this game? You have seen how Black exploited the weak c4 square in White's position to pressurize the c3 pawn. This was not a short tactical blow, but a slow, grinding strategic idea. By tying down White's pieces to the defence of the pawn, Black could achieve a dominating position with more active pieces. Later he would turn his attention to other weaknesses in my pawn structure, slowly alternating pressure among the various weak points until I finally blundered.

Sunday, January 18, 2015

Middlegame calculation practice

Before I start off, I want to say a few things about what I have been observing about y'all for the past year.

It's been nearly 5 months since I last wrote this article about our attitude towards chess. In these 5 months, most of you have shown good improvement in terms of attitude and skills, and for these people I am truly grateful for your commitment.

But at the same time, there are some of you who choose to remain in Category 3 even after reading my last article (or perhaps you didn't even realize there was a last article?). You think that you can treat the Chess Club as a place to skive and waste your time away. You refuse to change your attitude despite my earlier warning. And worst of all, you obstinately and willfully remain in this place instead of transferring to another CCA.

Well if you're still in Category 3, let me tell you what I think about you.

  • You are the one who gives our school team, NUSH and your family a bad name
  • You are a parasite sucking at our scarce manpower and resources
  • You are causing unnecessary stress to Darryl, Khaarthik, Jae Kerr, and anyone else in charge
  • You don't deserve to call yourself a Black Knight, neither should you sit in front of a chessboard and be called a chessplayer

Feeling angry or depressed now? Your fragile, pathetic heart can't take a few nasty words? Well all the more you're not fit to be in Chess, because real chessplayers need to control their emotions and handle large amounts of stress. In any case the "close" button is on the top right-hand corner, so go ahead and click on it. I dare you to.

If you're still reading this and you know you're one of the slackers, I leave you with two choices. One, change your mindset for the better and buck up. Two, get that CCA transfer form and get your a** out of this team right now. Please.

Because if you don't, then Darryl, Khaarthik and Jae Kerr will make sure you do. Without fail.

(P.S. To the rest of the team, I'm sorry for making you read this nasty rant, but at least you have an idea of how serious this problem is now)

...

So back to business. The following game arose during one of our games in last week's tournament:

Opponent vs Checkerboard 5
Kickoff 2015 Chess Tournament (Round 5)
Position after 9. Qb3

The task here is simple: Assess the position (Black to move), and propose a continuation for Black. You can use the following pointers to help you:

  • What is White's threat here? What possible ways can Black defend against it?
  • What tactical elements must both sides watch out for?
  • Does either side have a lead in development?
  • What are the relative strengths/activity of both sides' pieces?
  • How will the pawn structure change with your suggested line(s)?

Of course, the list is non-exhaustive, and you need not use all the pointers in your analysis. Just choose a few candidate moves and analyze the resulting lines, before deciding on which one you feel is the best.

Don't leave yet! Normally I give y'all the freedom to decide whether to take up these challenges, but today you MUST take part in this (you probably know why after looking at what I said earlier). Take note of the following:

  • All members of the team (except Year 1s) must attempt this challenge. Alumni and outsiders need not take part.
  • Don't give one move answers. Support your analysis with variations and some elaboration. Provide a persuasive argument for your answers.
  • Email your answers to lau_yanhan@yahoo.com.sg under the title "Change is the only constant"
  • Deadline for submission is 25 Jan 2015, 2359 hrs. That should give you more than enough time.
  • Still refuse to attempt? Well, I shall leave you to Darryl's mercy then.

I apologize for those who have busy schedules, but we really need to find a way to differentiate the real chessplayers from the slackers. So have fun, and hope to receive your replies soon!

Saturday, January 3, 2015

Rook endgame practice 3

So before you guys get absorbed back into Orientation 2015, I shall sober y'all up with solutions to the rook endgame challenge I gave on New Year's Day. Here is the first one:

Position 1: Can Black save the game regardless of the move?

If you still have vague recollections of the times when we talked about a rook-pawn on the 6th rank, then this will be easy. Here, Black draws by re-deploying his rook to the 6th rank to set up a Vancura Position.


We give White the first move here (although there is no difference with Black to move):

1. Kf3

Black must find a way to get his rook to the 6th rank. I hope you remember that keeping the rook behind the pawn doesn't work: 1... Ra2? 2. Ke4 Ra1 3. Kd5 Ra3 4. Kc6 Ra1 5. Kb6 Rb1+ and now the king has a shelter from the checks (this won't work if the pawn were on the seventh rank!) 6. Ka7! Re1 7. Rc8 (releasing the White rook) threatening Rc7, Kb7 followed by promotion of the pawn.

1... Rf1+!

Not giving White a chance to activate his rook. This is stronger than 1... Re1 2. Ra7+, and although Black can still draw with 2... Kg6 3. Rb7 Ra1 (discouraging any pawn advance), he might also fall for traps like 2... Kg8?? 3. Rb7 Ra1 4. a7 Ra2 5. Rb8+! with promotion on the next move.

2. Ke4 Rf6 (D)

With a pure Vancura Position; Black will just shuffle his rook along the 6th rank and check the White king if he gets too close to the pawn. Here are the links to the Vancura Position and the Pawn on the 6th rank to familiarize yourself if you haven't done so.

...

Our second position:

Position 2: Black to play, can he save the game?

If it were White to move it would be an easy Lucena Position: 1. Rg1+ followed by 2. Rc4 and the "bridge building" comes soon after.

What if it were Black to move? Fortunately for him, two factors contribute to him being able to hold the draw in this case:

  1. His king is on the short side of the board, and cut off by only one file
  2. His rook is already positioned on the long side of the board with sufficient checking distance.

Black employs the side-rank defense (the side-rank defense, as well as the long/short sides of the board, are discussed in this link) to save himself:

1... Ra8+!
2. Kd7

If Black's king were cut off by two files White could hide on f2.

2... Ra7
3. Kd6 Ra6+
4. Kc5 Ra7
1/2-1/2


White cannot approach Black's rook without hanging his pawn. And not 4... Ra5+?? 5. Kb5 when Black's checking distance has been destroyed.

For your information, I recently found out that there is a fancy name for the side-rank defense: The Karstedt Maneuver. To quote from Bernd Rosen in his book "Chess Endgame Training", "With the Karstedt Maneuver, the defender's king has to move to the short side in order to allow the rook enough space for side attacks. This defensive procedure only works if there is a distance of at least three files the king of the side with the pawn and the defender's rook."

With that in mind, we move on to the third position:

Position 3: Black to move, can he still draw?

With the Black rook now on b2 rather than b1, the side-rank defense no longer works because of insufficient checking distance (the rook is less than three files away from the king). White wins this easily.

1... Rb8+
2. Kd7 Rb7+
3. Kd6 Rb6+
4. Kc7!

Black cannot stop the pawn from promoting.

...

And with that we're done with another rook endgame analysis. All the best for the year ahead!

Links:
Practice 1: http://nushsblackknights.blogspot.com/2014/12/rook-endgame-practice-1.html
Practice 2: http://nushsblackknights.blogspot.com/2014/12/rook-endgame-practice-2.html

Sources:
"Silman's Complete Endgame Course" by Jeremy Silman
"Rosen's Chess Endgame Training" by Bernd Rosen

Thursday, January 1, 2015

Back-to-school challenge: Rook endgame practice 3

Well it's 2015, and many of you must be dreading the long awaited return to school (not me, at least!). Well then why not gather your wits back with some rook endgame practice after the vacation? Here are three simple positions for you to challenge yourselves:

Position 1: Can Black draw regardless of the move?

Position 2: Black to play, can he save the game?

Position 3: Same as Position 2 except that the Black rook is on b2. Can White win or is Black able to save the half-point?

For your reference here's the "database" of rook endgames that we have covered so far:


...

Have fun, and Happy New Year! (: