Friday, March 14, 2014

Rook + 4th rank pawn vs Rook: Part 3

We will wrap up our discussion of this topic today. By now our experience with rook endgames is enough to tell us that positions with rook pawns always prove to be exceptions to endgame norms; but in this case, even knight pawns have become an exception!

What do I mean!? Well there's only way to find out why: Tackle the problem head-on!


Knight pawns

Draw... but why?

(See the KnightVision viewer below for better visualization)

1. Re2

1. Kh4/Kf4 will be met by a rook check from the 8th rank, and after retreating back behind the pawn White won't make any progress. So he can only pass time and hope for Black to mess things up.

Now here's the interesting bit. How should Black play now?

To make things simple I'll present four choices over here: Only one of them draws, while the other three lose for Black.

1... Rg7
1... Ra8
1... Kd4 
1... Kd6
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Let's look through them one by one.

1... Rg7? destroys the Black rook's checking distance, so not surprisingly it loses after 2. Kh4 Rh7+ 3. Kg5 Rg7+ 4. Kh5 Rh7+ 5. Kg6

1... Ra8? is clearly not the way to go because after 2. g5 we have a winning position with the pawn on the 5th rank, and the Black king cut off by 2 files on the long side of the board (Have fun browsing back if you're unfamiliar: http://nushsblackknights.blogspot.sg/2014/02/rook-5th-rank-pawn-vs-rook.html)

After 1... Kd4? things start to get interesting, but Black loses after 2. Re6 Kd5 3. Rh6!

Black loses!

And suddenly White has cut off the entire 6th file and beyond to the Black king! Now White can simply walk his king up to h5, and slowly advance his pawn past the 5th rank. So for example the game can continue: 2... Ke5 4. Kh4 Kf4 5. Rf6+ Ke5 6. g5 Rh8+ 7. Kg4 and Black loses because his king is cut off by one file along the long side of the board.

...

So that leaves us with one last option:

1... Kd6!

Surprising, but it works! Let's see how:

2. Re4

Of course 2. Kh4 is met by 2... Rh8+, while 2. Rd2+ (or any other move that takes the White rook off the e-file) allows the Black king to get closer to the pawn with 2... Ke5

2... Kd5

And now we see the point of 1... Kd6: Black can now shuffle between d5 and d6 (preventing White from winning by the Re6-Rh6 maneuver) and White cannot advance the pawn because it is being shadowed by Black's rook.

Of course, 2... Kd7? loses after 3. Kh4 Rh8+ 4. Kg5 Rg8+ 5. Kf6 Rf8+ 6. Kg7 1-0

3. Re1 Kd6
1/2-1/2

White cannot make any progress as long as Black keeps his king on d5 and d6.



...

That seemed easy, but by now perhaps some of you might be wondering why this Kd5-Kd6 maneuver does not work if the pawn were a central/bishop pawn? We will look back now and see why; at the same time this will also help us understand why knight pawns are exceptions to the general rules for this position.

Perhaps before we progress you might want to do a little revising: http://www.nushsblackknights.blogspot.sg/2014/03/rook-4th-rank-pawn-vs-rook-part-2.html

How did White win again...?



Suppose we gave Black the move now:

1... Kc6

But this time White won't need to resort to Re4; he has something more effective:

2. Kg4! Rg8+
3. Kh5 Rf8

3... Rh8+ 4. Kg6 will slowly destroy the Black rook's checking distance

4. Rf1

And now we see why knight pawns are exceptions: Had the pawn been on g4 rather than f4, White would not have been able to use the Kh5-Rf1 trick because the short side of the board is too narrow for him to do that! In this position, White now wins because Black's king is too far away to reach the pawn in time

4... Kd5
5. Kg6
1-0

And the pawn will slowly advance to f7 under king and rook protection, while the Black rook will eventually be forced out of its passive position.


Rook pawns

As usual rook pawns are always exceptions which tend to be a bother for the stronger side:

Dead draw

And the draw is simply too easy for us to see here: White's king has no file on the right to step onto, and if he tries to step out from the other side with 1. Kg4 then Black just trades rooks with 1... Rg8+ 2. Kf2 Rxg1 3. Kxg1 reaching a drawn rook-pawn position. So Black can simply shuffle his rook between h8 and h7, and if 1. Rf1+ then alternating his king along the f and g files should seal the draw.

Once again as a personal challenge you can try finding out how many files the Black king has to be cut off by before White can secure a win. Of course you might want to refer to the following link: http://nushsblackknights.blogspot.sg/2013/12/a-lucena-with-rook-pawn.html


Wrapping up

Alright, we're going to pause our study on rook endgames for now, so as to let y'all prepare for our upcoming National Individuals. Brush up on your tactics, familiarize yourself with a couple of opening repertoires and learn some important positional concepts. As for rook endgames, do try to consolidate what we've learned so far. It is important that you know at least the basics before facing the enemy next week.

We will resume our journey after NSI is over. All the best, guys!

Links:
Pawn on the 5th rank: http://nushsblackknights.blogspot.sg/2014/02/rook-5th-rank-pawn-vs-rook.html
Pawn on the 4th rank Part 1: http://nushsblackknights.blogspot.sg/2014/03/rook-vs-4th-rank-pawn-rook-part-1.html
Pawn on the 4th rank Part 2: http://nushsblackknights.blogspot.sg/2014/03/rook-4th-rank-pawn-vs-rook-part-2.html

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

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