Tuesday, December 31, 2013

New Year Present!

Well I guess since everyone's celebrating the New Year I may as well jump onto the bandwagon and start giving out presents. So what better way to start 2014 with a composed mate-in-2?

Pal Benko
Magyar Sakkélet, 1974
1st Prize
White to move and mate in 2

Have fun! (:

Sunday, December 29, 2013

A "Lucena" with a Rook-pawn!?

Well I promised that we will advance beyond basic rook endgames and look at more complex position. The problem is, the theory of rook endgames is just so vast and numerous I possibly can't finish going through all of them within a few posts. But even if we can't finish, surely we must start somewhere right?

So let's start off by going through one of the positions I promised that we will look at: A "Lucena" Position with a rook-pawn. Firstly, lets refresh our minds with a pure Lucena Position:

White to move wins

The winning strategy for White should be familiar to all of us by now (well I hope you do remember it right? If you've forgotten, go back to the basics and read through it NOW!!!!) http://www.nushsblackknights.blogspot.sg/2013/12/revising-basic-rook-endgames-part-1.html

And of course we know that in order for White to win, the weaker side's king must be cut off by at least one file from the enemy pawn. For example if the Black king in the earlier position were on d6 and White's rook on c2, then Black's king makes contact with the opposing pawn and White cannot win.

But also note that this one-file rule only applies if the pawn is a centre, bishop or knight pawn. If the pawn is a rook pawn, then the "Lucena" Position is a win only if the weaker side's king is cut off from the enemy pawn by four or more files!

(Note I am using inverted commas for the word Lucena, because a real Lucena Position only occurs with a centre, bishop or rook pawn)

Sounds weird? Let's look at the following position where Black's king is cut off by only one file:

Draw no matter who to move!

The position speaks for itself-- the rook pawn is all the way to the side of the board, the White king can only hope to step out of one side of the pawn shelter (because there's no other side!) and that side is being shadowed by Black's king.

So let's say it is Black to move, then all he needs to do will be to play 1... Rc1 blocking any irritating checks, and after 2. Rb7+ (or 2. Rh2 Kc8 3. Rh8+ Kc7) Kc8 3. Rb8+ Kc7 it is quite clear that Black can just shuffle between c7 and c8, and White's king is trapped behind the pawn shelter.

Now if it were White to move instead, after 1. Rc2+ Kd7 (1... Kb6 2. Rc8 Ra1 also draws) and then the variations are as follows:

-2. Rd2+ Kc7 and White isn't getting anywhere
-2. Kb7 Rb1+ and White's king must retreat to the pawn shelter again
-An attempt to "build a bridge" with 2. Rc4 fails to 2... Rb1, as the only way out for the White king is via the b-file (the pain of being at the side of the board!) which is under fire from the Black rook.

With a dead draw.

Next we're going to see why cutting off the weaker side's king by three files isn't enough to force a win. I'll skip the position with two files; once we've learned the method to force a draw with the king three files away, then the position with two files should be quite intuitive.

Still a draw

Similar to a real Lucena the Black rook prevents White's king from venturing out of the pawn shelter; and believe it or not, Black's king is still close enough to help his rook!

If it is Black to move he will simply shuffle his rook along the b file, so let's give White the move here:

1. Rh2

Once again, White cannot hope to build a bridge with 1. Rd4 (or as a matter of fact, any other move!) since the only way out for the White king is via the b-file, which is controlled by Black.

1...Kd7 2. Rh8 Kc7 3. Rb8

Hoping for 3... Rxb8?? 4. axb8=Q

3... Ra1 4. Rb7+ Kc8 5. Rb2

And now we have a position resembling that of our first example, where Black can simply play 5... Rc1 to block any annoying checks. Similar to our first position, Black can now just shuffle along c7 and c8 and White's king can never hope to leave the pawn shelter.

...

Now that we've learned how such a position is a easy draw for the weaker side with three files or less, lets look at the real thing-- when the weaker side's king is four files away from the pawn!

White to move wins

White's plan is to chase Black's rook off the b-file by getting his own rook to b8, so that his king can safely leave the pawn shelter. However, the method is not as easy as you may think, so hold on tight!

1. Rc2 Ke7
2. Rc8 Kd6

After 2... Kd7 3. Rb8 Ra1 4. Kb7 (and 4. Rb7+? Kc8) 4... Rb1+ 5. Ka6 Ra1+ 6. Kb6 Rb1+ 7. Kc5 White's king will slowly walk towards the Black rook and lope it off

3. Rb8 Ra1
4. Kb7

White's first task is complete: The king has left the pawn shelter. Now his next task will be to escape from the barrage of checks...

4... Rb1+
5. Kc8 Rc1+
6. Kd8

And the second task is complete, but White's troubles aren't over yet!

6... Rg1!
7. Rb6+


The greedy 7. a8=Q?? leads to an embarrassing 7... Rg8#, while after 7. Ke8? Re1+ 8. Kd8 and White hasn't made any progress

7... Kc5 (D)

A critical moment

8. Rc6+!

The key move that ensures White's victory in this position. 8. Ra6? is a draw after 8... Rg8+ 9. Ke7 Ra8 with 10... Kb5 to follow. But now Black should find it best to accept the rook sac, allowing White to promote with check and reach a Queen vs Rook endgame

8... Kxc6
9. a8=Q+ (D)
1-0

White wins

And in this Queen vs Rook endgame, White should win easily because Black's king is far away from his rook (Queen vs Rook endgames become difficult only when the weaker side's king is close to its rook), so a series of checks plus some bit of caution should be enough to land Black in a fork. I will not show the details here, but will include a sample variation in the following KnightVision viewer:



And so here we have, the "Lucena" with a rook pawn endgame. The message to take away is simple: Such a position is a win for the stronger side only if the weaker side's king is cut off by four or more files from the opposing pawn. Of course, the details and methods to force such a win (or forcing the draw if there are three files or less) have already been explained above, so feel free to read through it again.

Sources:
"Silman's Complete Endgame Course" by Jeremy Silman

Tuesday, December 24, 2013

Christmas Presents (Yayyy!)

It's the season guys! Now who wouldn't like better Christmas presents than the 8 (simple) tactical gifts that y'all going to receive now? Better 'n Santa's gifts, yeah?

Puzzle 1: White to move

Puzzle 2: White to move and mate in 3

Puzzle 3: Black to move and mate in 2

Puzzle 4: Black to move and mate in 3

Puzzle 5: Black to move

Puzzle 6: White to move (be careful!)

Puzzle 7: Black to move and mate in 4

And of course the best candies go to the ones who can earn them: If you thought the first 7 were too easy, here's one last composed mate-in 3:

Puzzle 8: White to move and mate in 3

Enjoy your presents, and Merry Christmas! (:

Friday, December 20, 2013

Revising Basic Rook Endgames; Part 3

In the last section of our revision we shall take a look at how a rook can active or passive in a given position, and the consequences.

The long-ranging capabilities of the rooks enable them to serve multiple roles throughout the course of a game. They protect the king in a castled position, seize open files, and help to support the advance of passed pawns. From our our revision in Part 2, we can also see that they have the ability to cut off entire files to prevent the advance of enemy infantry.

However, rooks also have their own weaknesses. When blocked by enemy or friendly pieces their long-range powers become limited, and they instead become targets for attack. If not placed in a proper position they can actually become passive pieces, tied down to the defence of weak spots and succumbing to the powers of more active enemy pieces. Hence the terms active and passive rooks come about, and they are an important factor which often decides which direction the endgame swings.


Active and Passive Rooks

From Part 2 we saw how putting a rook behind a passed pawn is effective in helping/stopping its advance, as compared to a rook in front which gets in the way. In fact, this is a special case of active vs passive rooks-- the rook behind the pawn is usually more active since it has more freedom to move about and yet watch over the pawn at the same time.

To have a better understanding of the terms active and passive, let's take a look at the following position:

White's rook is active, while Black's is passive

A quick glance can see that White's rook is better off than Black's. White's rook is attacking the pawn on a7, and can roam around the 7th rank or switch to attack another target if he wishes to. On the other hand, his Black counterpart is tied down to the defense of the a7 pawn, and cannot move anywhere else as long as White continues attacking a7. To put it in another form, White has the "dominant", or active rook, while Black has the "slave", or the passive rook.

(And over here, Tarrsch's rule of putting the rook behind the pawn definitely does not apply!)

While this may seem trivial in the simple position shown above, the concept of active and passive rooks can be externally useful when it comes to more complex positions like this:

White to move

Black is a pawn up, but White simple seizes the advantage with the move:

1. Rd7!

After which it is quite clear that White's rook is more active than Black's: He attacks the a7 pawn and ties down the enemy rook to its defense. White's plan will be to use his active rook to pin down the enemy king and rook, while his own king moves in and helps pick off the Black pawns.

1... Kf8
2. Rb7 Ke8
3. Kc3

Not falling for 3. Kd3? Rd8+ 4. Ke4 Rd7 5. Ke5 Ke7

3... Kf8
4. Kd3 Rd8+

After 4... Ke8 5. Ke4 Kf8 6. Kd5 Rd8+ 7. Kc6 Rc8+ 8. Kd7 Ra8 9. Rc7 the White king will enter via Kc6-Kb7 and Black's pawns will fall one-by-one

5. Ke4 Rd4+

Black manages to activate his rook but the White king has already forced his way into Black's pawn mass.

5... Re8+ 6. Kd5 Re7 (6... Rd8+ 7. Kc6 Rc8+ 8. Kd7 Ra8 9. Rc7) 7. Kd6 Re6+ 8. Kc7 Re7+ 9. Kb8 also wins for White

6. Ke5 Rxc4
7. Rxa7 Rxh4
8. Rd7!

Another alternative, but not-so-strong variation for White is 8. Rb7 Ra4 9. Rxb6 h4

8... Ra4
9. a7 Kg7 (D)


9... Ke8 loses even faster-- after 10. Rb7 h4 11. Rb8 +-

Despite being two pawns down, White is winning here because 1. His passed pawn is further ahead compared to Black's 2. His king is in the action while Black's is sitting on the sidelines and 3. Black's rook is tied down to guarding the a file to prevent White's pawn from promoting. White now wins by walking his king over to the b file and escort the pawn to promotion, while his rook leaps to the first rank to stop Black's passed pawn. The resulting variations I will show in the KnightVision viewer:


Throughout the study we see how White's active rook ties down Black's passive counterpart by attacking vital squares, thus allowing the White king to enter and escort the pawn to promotion. This is just one of the many examples of the dominance of active rook over passive ones.


...

The activity of a rook is also decided by its ability to quickly respond to new and emerging threats across various parts of the battlefield. Rooks are most lethal when they are mobile; a rook that is blocked by friendly/enemy pieces cannot maneuver quickly across the board and is therefore passive, akin to a piece of armour bogged down in the mud.

Hey but it's still an excellent pillbox, though the most expensive one in the world!

The difference between a rook that can move about freely and one that cannot may be enough to make a difference, as we can see in the next example:

White to move and pick up the point

Looks...a little like the Philidor Position right? But it isn't, because it is White to move here and White can win! Black's rook is bogged down-- it cannot leave the 1st rank because of the threat of 1. Rh8#. White wins easily by swinging his more active rook over to the other side of the board:

1. Ra7!

And the threat of 2. Ra8# forces Black to continue 1... Ke8 2. Ra8+ (2. d7+ Ke7 3. Kc7 also wins) Kf7 3. Rxg8 where after 3... Kxg8 the resulting pawn endgame is a no-brainer win for White.

Remember how we talked about the "swing the rook to the other side of the board" trick in Part 1? Now you see it again here, and that's one of the reason why active rooks often dominate over passive ones!

And with that I close off our revision on basic rook endgames. By now most of these should be trivial to y'all, but do spend some time going through them again. What we have gone through-- Lucena and Philidor Positions, active and passive rooks, and other basic stuff-- will serve as important building blocks in our study of more complex rook endgames in the future.

Links:
Part 1: http://nushsblackknights.blogspot.sg/2013/12/revising-basic-rook-endgames-part-1.html
Part 2: http://nushsblackknights.blogspot.sg/2013/12/revising-basic-rook-endgames-part-2.html

Sources:
"Silman's Complete Endgame Course" by Jeremy Silman
http://www.strangevehicles.com/content/item/120829.html

Saturday, December 14, 2013

Revising Basic Rook endgames: Part 2

In our previous section we revised two basic positions (well I hope they're still fresh in your mind!) and saw the winning/drawing strategy behind them. Today let us take a look at other basic functions which rooks have in the endgame: 1. Cutting off enemy units from the main action and 2. Escorting or preventing the promotion of passed pawns.

Cutting off ranks/files from the enemy

In our revision of the Lucena and Philidor Positions we saw how the rook was able to fence off an entire row of squares to prevent the opposing king or pawn from stepping across it.

Philidor Position: Black's rook fences off the entire 6th rank from the White king

And yes-- it is indeed the long range capabilities of the rook that enables it to lay suppressing fire along a rank or file to cut it off from enemy infantry. As we are to see this is an extremely useful tool be it in attack or in defense-- for when the enemy is approaching, CALL IN THE BARRAGE!!!

Will there still be Huns left for us to fight, sir?

Alright let us see how this actually works. Look at the following position:

White to play and win

Over here Black is down in material, but he knows that if he can trade off his pawn for the enemy rook the game will be a quick draw. So he will try to use his king to escort the pawn to promotion and lure the rook in for an exchange. White, obviously, does not want the pawn to promote, so he must find a way to win the Black pawn without having to sac his rook. Which seems to be quite of a problem for him, since his king is too far away to participate in the action...?

But one thing ensures victory for White. The Black king is separated from the pawn by a file, so White simply severs their connections with the simple:

1. Rh5!

And not 1. Rh4? or 1. Rh6+? where after 1... Kb5! Black's king makes contact with the pawn, and White can no longer hope to win the pawn without having to lose his rook.

And with the 5th rank fenced off Black cannot hope to escort the pawn safely down the board, for 1... c3 is met by 2. Rh3 winning the pawn, while any king move is met by 2. Kf7 and the White king will eventually move in to take out the pawn.

(It is interesting to note that if we shifted the Black king and pawn down one square, the strategy will not work because after 1. Rh6 c2! the pawn is on the verge of promotion and White cannot hope to play 2. Rh2?? and win the pawn. But nevertheless in this example we can see the power of using rooks to deny the opponents access to entire ranks/files)


Want another example? Here goes:

White to move

Black is a pawn down, but he can hope to save half a point if he is able to get his king in front of the pawn and create a Philidor Position. IF.

And his dreams are busted the moment White plays 1. Rf1! cutting the Black king off and preventing him from ever reaching the pawn. After 1... Rf7 2. Rxf7 the resulting king-pawn endgame is a win for White.


The idea of using rooks to cut off ranks/files does not always have to be a tool for the stronger side; in our next example, the weaker side uses the same concept to force a draw.

Black to play and draw

White wants to play Kc5 and win the d5 pawn, after which his two-pawn advantage should be enough to ensure victory. But Black manages to find a good defending move by denying White access to the c-file:

1... Rc8!

And by simply shuffling his rook along the c-file White cannot find any way to reach the mass of pawns in the centre; for example after 2. Kb5 Black continues with 2... Rf2 hitting the f2 pawn.

As such we can see how the long-range capabilities of the rook enable it to fence off whole ranks/files from the opponent, which comes as a useful endgame tool be it in offense or defense.


The escorting of passed pawns

A infantry battalion assaulting a fortified base usually cannot complete the mission on its own; The soldiers have rely on airstrikes or artillery support to clear out any major threats, before moving in to capture the base.  Similarly a passed pawn advancing across the board cannot reach the other side all by itself. It needs close support from friendly pieces, which help to remove any obstacles in its path to promotion. Without this support the pawn cannot make inroads into the enemy camp, and instead becomes a vulnerable target of attack.

And in rook endgames, the two pieces tasked with escorting passed pawns-- and similarly the enemy pieces which stand in its way-- are the king and the rook. In such positions, Tarrach's old quote about rooks and passed pawns come to mind:

"Always put the rook behind the pawn.... Except when it is incorrect to do so."
-- Siegbert Tarrasch


The logic behind this is quite simple-- the infantry should be the one in front doing the chiong sua while the artillery supports it from behind, not the other way round. While there are some exceptions to this rule (see http://en.wikipedia.org/wiki/Tarrasch_rule for some exceptions) we're gunning for concepts, not brute force memorization over here. So for now let us accept that Tarrach's rule holds true for the majority of rook + passed pawn endgames.

White to move

Tarrasch's rule holds quite clear in this position: White's pawn is well supported from the rook behind, and the Black rook is helplessly tied down to the defense of the h8 square. White wins by walking his king over to g7 (he has the opposition since it is his turn to move) and chasing away the Black rook.

On the other hand, if we switched the positions of the rooks:

Draw no matter who to move

Once again we see the power of Tarrach's rule: Now White cannot move his rook for fear of 1... Rxh7 with a draw! So all Black has to do is to shuffle his rook along the h-file (and not falling for 1... Kc7?? 2. Ra8! where after 2... Rxh7 3. Ra7+ Black loses) and White can never make progress.

In actual rook endgames the methods for winning/drawing is often not as simple as what I've shown above (we'll go through some of the challenges faced in later articles), but the first step is always the same-- in most cases, when escorting or preventing the promotion of far-advanced passed pawns  you should try to put your rook behind the passed pawn regardless of which side it is on. This is an important thing to note when it comes to rooks + passed pawn endgames.


So in case you've become lost after reading all those text above, I've summarized what we've revised today into two simple points:

  1. The long-range abilities of the rook enable it to cut off whole ranks/files, thus denying opposing kings/pawns access to them. This can become an extremely useful tool in both offensive and defensive tactics
  2. When escorting or preventing the promotion of passed pawns that have advanced far up the board, Tarrach's rule (to put your rook behind the passed pawn) holds true for most cases.

Similar to Part 1, do take your time and revise these basic concepts, for they will serve as valuable guiding posts when it comes to learning more complex endgame positions in the future.

Links:
Part 1: http://nushsblackknights.blogspot.sg/2013/12/revising-basic-rook-endgames-part-1.html

Sources
"Silman's Complete Endgame Course" by Jeremy Silman
http://vuel-iqbal.blogspot.sg/2012/05/operation-bagration-is-go.html
http://en.wikipedia.org/wiki/Tarrasch_rule

Sunday, December 8, 2013

Revising Basic Rook endgames: Part 1

Rook endgames are complex. Somehow we never seem to be able to grasp the full power of heavy artillery, and the real irony is that we encounter it the most often in endgame play. That's why I'm planning to go through some of the more complex rook endgame positions, but before we venture into these deep waters I want to make sure all of us are fully oriented with the basics.

Cos after the infantry's blown to bits they're the only bloody sods left

So let's start our revision with the two most basic, must-know positions in rook endgames: The Lucena and Philidor's Positions. Yes, Mr Lim and I have already covered them several times throughout the year, so take this as an opportunity to revise what you've already learned.

Both the Lucena and Philidor's Positions aren't that difficult to master, and in turn you'll encounter them quite often in tournament play, and they will serve as valuable basic tools for you to master more complex rook endings. So here goes:

The Lucena Position: Building a Bridge

The most basic form of a Lucena consists of both sides having a rook+king, but the stronger side has a pawn on the 7th rank:

White to play and win

(Note: The outcome is still the same whichever side to move, but for clarity's sake we'll give White the move here)

The most obvious thing about this position is that the stronger side (White in this case) must try to promote his pawn in order to force a win, but to do he must first get his king out of the way. But this is easier said than done: Black's rook cuts off one entire file, while his king shadows the other file so White's king cannot even step out.

So White's first task will be to cut the enemy king away from the action. Now 1. Rd7+? fails since Black can simply alternate between Kc7 and Kc8, shadowing the escape squares d7 and d8. So White should play:

1. Rc2+ Kb7

1... Kd6?? allows 2. Kd8 and the pawn is free to promote

The Black king is now cut off from the main action-- White is now free to move his king over to the d file and give his pawn room to promote. But here comes another problem: Black's rook on the 1st rank is threatening to force a draw with a barrage of checks should the White king step out of his shelter behind the pawn. But if the White king does not step out, the pawn cannot promote anyway!

Alright, come out if you dare!

So for example after 2. Kd7 Black can just keep checking with 2... Rd1+ 3. Ke6 Re1+ 4. Kd6 (4. Kd5?? Rxe7 is an instant draw) 4... Rd1+ and after 5. Kc5 Re1 White must retreat to protect his pawn, and has not made any progress.

And thus White's rook must come to the rescue again-- this time to provide another shelter for the Monarch to hide from the enemy's artillery barrage. Nimzowitsch fondly called this maneuver "Building a Bridge":

2. Rc4! (D)


Looks like one of the moves that we least expect, yet it works! This critical move helps to "build the bridge" for White as we will see:

2... Rd1
3. Kf7 Rf1+
4. Ke6 Re1+
5. Kf6 Rf1+
6. Ke5 Re1+
7. Re4 (D)
1-0

Building the bridge

And now White's king has a safe haven to shelter from the relentless checks, and there is no stopping the pawn from marching to promotion.


Remember: The Lucena Position is always a win for the stronger side, and the method to winning this comes in two basic steps:

  1. Trap the enemy king away from the main action by 2 ranks or more so that he cannot interfere when your king leaves the pawn shelter
  2. "Build a bridge" with your rook to shelter your king when he leaves the pawn cover. Remember the weird-looking 2nd move in our example-- it is the critical move!

You may ask: So does this plan apply even if the pawn is a non-central pawn-- say a bishop, knight or even rook pawn? We can safely say yes for central, bishop and knight pawns... but not really the case for rook pawns! However, we will only examine this special case of Lucena rook pawns in future articles-- for now, please absorb the content thoroughly before we proceed to more complex stuff!


The Philidor Position: An impenetrable wall

So now let's take a look at another basic rook position:

Black to play and draw

(Note: In this position we give Black the move for now. If White has the move things will turn out quite different [because of 1. Rb6 seizing control of the 6th rank], but it is still possible for Black to force a draw. The method utilized will be discussed only in later articles, and by that point we will require a firm understanding of the basics)

Yes-- it's the Philidor's Position. Now although White has an extra pawn, and a seemingly more active rook, the position is dead drawn. So if you have forgotten the method used to force a draw, here goes:

1... Ra6!

The best way! White wants to advance his pawn to the queening square-- but to do so he has to keep it supported with the king. So Black foils the plan by cutting off the entire 6th rank and preventing White's king from stepping forward.

Now the intuitive  1... Rd7? (trying to block Ra7+) fails because White can simply swing his rook over with 2. Rh8! followed by 3. Rh7+, sneaking into a winning king-pawn endgame.

The alternative move, 1... Ra1 (attempting to produce a barrage of checks on the White king from the 1st rank) will also fail because of 2. Rb7+ Ke8 3. Ke6! after which 3... Ra6+ is met by 4. e6 and 3... Rf1+ is met by 4. Ke6 (and both threaten 5. Rb8# on the next move).

(Despite this, it is actually STILL possible for Black to force a draw even after 1... Ra1, but the method employed is much harder and more complicated than the one we are going to discuss. So for now let's toss that idea aside and focus on 1... Ra6, keeping things simple.)

Returning to the position after 1... Ra6:

2. Rb7+ Ke8
3. Rc7 Rh6 (D)

Fencing off the 6th rank

Black has no intention of giving up his control over the 6th rank! By shuffling back and forth along the 6th rank, he ensures that the enemy's progress is cut off by this impenetrable wall which cannot be breached, assuming the White king is not a Kaiju.

Which if it were, the game would take a very different course altogether

So White, now frustrated at not being able to break through, decides to try something different:

4. e6

And now!

4... Rh1 (D)

No shelter for the king

The point! With the pawn shelter removed, Black can now leap to the back rank and unleash unstoppable checks on the enemy! Even if White tries to get close to the rook with let say 5. Kg5 Rg1+ 6. Kf4 Rf1+ 7. Kg3 then 7... Re1 forces White to defend the pawn and no progress is made. White cannot prevent a draw in this situation.


And so the way to draw a Philidor Position also comes with two basic steps:

  1. Similar to the Lucena Position, the weaker side has to use his rook to fence the enemy king off-- this time prevent him from getting to the 6th rank where he can help with advancing the pawn.
  2. Should the stronger side try to intrude the 6th rank by advancing his pawn, that means he has effectively destroyed his pawn cover-- which means it's time for the weaker side's rook to leap to the back rank and start raining down checks on the enemy king!

And so there we have the Philidor's Position. But before I close off Part 1, I want to divert our attention for a little while-- remember how in our second example I said 1... Rd7 won't work? That's because White still has the capability to leap his rook to the other side of the board with 2. Rh8 (and here White's rook IS clearly more active than Black's), thus rendering Black's hopes of blocking any checks useless. But if we made some slight shifting of the coordinates, the outcome of the battle will be very different altogether:

Dead draw!

Well all I did was to move the kings and pawn to the right by 2 squares, right? But in this case 1... Rf7 WILL draw, simply because the White rook has no room on the other side of the board to check the enemy king! So for example after 1... Rf7 2. g6 Re7 then Black can simply shuffle his rook forever on the 7th rank without ever needing to leap to the first rank as in an ordinary Philidor (though he may like to throw in moves like Re5+ just to add some variety).

This concept of switching sides of the board is a very important one in rook endgames, and often the one which establishes the dominance of active rooks over passive ones.

And so we'll continue our revision on basic rook endgames in Part 2, but be sure to have the concepts of both the Lucena and Philidor positions firmly ingrained in your mind!

Sources:
http://www.historyplace.com/worldhistory/firstworldwar/brit-artillery-attack.htm
www.socamo.com
http://thisisinfamous.com/pacific-rim-review-john-shade-vick/ 
"Silman's Complete Endgame Course" by Jeremy Silman

Wednesday, December 4, 2013

More Random Tactics

To keep this page alive here's a few more puzzles for you to try. 8 (simple) puzzles on random tactics, have fun!

Puzzle 1: Black to move

Puzzle 2: White to move and mate in 2

Puzzle 3: White to move

Puzzle 4: Black to move

Puzzle 5: White to move

Puzzle 6: Black to move

Puzzle 7: Black to move and mate in 3

Finally, another composed mate-in-2 just for the fun of it-- attempt if you have the time

Puzzle 8: White to move and mate in 2

Enjoy! (:

Saturday, November 30, 2013

Tragedy of a fianchettoed bishop

So having learned the Sicilian Dragon, KID, Larsen Attack, and all other random openings featuring a fianchettoed bishop, you might probably be well aware of the power of such a bishop in an attack against the castled king. But a fianchettoed bishop can have its weaknesses too; sitting at the side of the board, it can easily become a sitting duck should its path along the long diagonal get blockaded by enemy (or even friendly) pawns. The following game shows how this may lead to disastrous consequences:

Opponent vs Checkerboard 5
Children's Day Chess Challenge 2013


1. f4 Nf6
2. Nf3 e6
3. b3 Be7
4. Bb2 b6
5. e3 Bb7 (D)


Played without much realization of what will be to come. In several of my earlier games I had played the Old Queen's Indian with much success against irregular openings, much thanks to the solid and flexible nature of the pawn structure. However, I had yet to test it against a strong kingside attack, which will soon turn out to be the critical test of the setup.

6. Be2 d6
7. O-O Nbd7
8. d3 h6
9. Nbd2 c5
10. c4 O-O
11. h3 Nh5

To hit g3, gaining a tempo. My opponent had plans for the kingside, so of course he did not want this.

12. Qe1 Rc8
13. g4 Nhf6
14. Qg3 (D)


Here he comes. The activity of his kingside pieces, coupled with both the upcoming pawn avalanche and HIS fianchettoed bishop on b2, is more than enough to let me know that a major assault is upcoming.

14... Nh7
15. e4 Bf6!

When defending, the best strategy will be to exchange off the opponent's pieces to weaken the force of his attack. The b2 bishop was the best target here since it was hovering over the vulnerable g7 square.

16. Rab1?!

Fritz prefers the variation 16. e5 dxe5 17. fxe5 Bg5

16... Bxb2
17. Rxb2 (D)


17... Qe7

Now after some helpful analysis by Fritz, I feel that a much better option for me would have been to launch the pawn break immediately with 17... f5! After the variation 18. g5 (18. e5 dxe5 19. fxe5 f4 20. Qf2 leads to the same consequences, while 18. exf5 exf5 19. gxf5 Qf6 also helps to free my b7 bishop and bring my pieces over to the kingside quickly) 18... hxg5 19. fxg5 f4 White's attack is blunted. Although I still have the problem of trying to free my b7 bishop (which is still being hemmed in by the e5 pawn), at least my position is much less cramped than the one after the text move.

18. h4 f6
19. Rf2 e5?

The wrong break at the wrong time! After 19... f5 20. g4 h5 where the threat of fxe5 followed by d5 could still give me chances to free my b7 bishop. Now after the text move, White responds a move which leads to the permanent imprisonment of my bishop:

20. f5! (D)


20. fxe5 dxe5 removes the momentum from White's pawn avalanche.

A swift glance at the position can be enough to tell that things are not going well for me. White controls most of the space in the centre, which allows him to swiftly mobilize his pieces over to the kingside for the attack (his king, despite being on the kingside, is not getting in the way due to the space in the centre). Most of my pieces are in dug-in defensive positions, which is not that bad altogether since I can meet my opponent's threats...

Only except that I am a piece down. Look over to the fianchettoed bishop on b7-- I had placed it there in the opening without much thought of the fate that would befall it, and now one can tell that it has been literally cut off from the main action by White's pawn chain in the centre. To free it would cost several tempi (and moving lots of blocking pieces out of the way), which by then White would probably already have broken through.

Thus with the fianchettoed bishop sitting there and unable to participate in the defense of the kingside, I am as good as a piece down.

20... Kf7

I could not just sit there and watch White overrun my position-- when the command post is under fire His Majesty must evacuate to a safer place.

21. g5 hxg5
22. hxg5 Ke8

22... fxg5 23. Rh2 Rh8 24. Rxh7 Rxh7 25. Nxg5 Kg8 26. Nxh7 Kxh7 was the better alternative, but my bishop is still a prisoner on b7.

23. Nh4! Rg8
24. Bh5+ (D)
1-0


I stopped recording here; as the game continued I actually managed to evacuate my king successfully to the Queenside, but by then White had already broken through with his "extra piece" and won material.

As such, let this game be a reminder to self and everyone here that a fianchettoed bishop is not always an advantage. While it can prove to be a strong attacker when in control of the long diagonal, it can also become easily cut-off from the game, especially when the centre is closed.