1Q1nb3/p3k1pp/3p1p2/1B1p4/PK1B4/4P3/5PPP/2r5 b - - 0 1

Endgame of the Week (416)

This is a won game for White.

How does he win if it's Black's move?
How does he win if it's White's move?

8/5k2/5P1p/5K1P/8/8/8/8 w - - 0 1

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Solutions Update

Problem 1 - White To Play

7r/rp3q1p/1B1kbp2/1B1p2p1/2P5/P7/1P4PP/2KRR3 w - - 0 1

White's 2 bishops combine to cut off the Black king's escape:

1.Rxd5+ Ke7
2.Bc5#

Update:

Also possible is

1. Rxd5+ Bxd5
2.c5#

Thanks to Jeff Lebowski and Off the reservation.

Problem 2 - Black To Play

k1r4r/pppRQqpp/5p2/8/2P5/1P3P2/P4PPP/4K2R b K - 0 1

Yes, it does matter. If 1...Rce8, White can wiggle out of the pin with 2.Rd8+! (deflecting Black’s rook), which was pinning the white queen:

1...Rce8
2.Rd8+ Rxd8
3.Qxf7

So using the 'h' rook is the better choice:

1...Rhe8
2.Qxe8 Rxe8+
3.Kf1 Qxd7

Problem 3 - White To Play

1nbqnrk1/1pp1bp1p/r6Q/3B4/1p2P3/8/PBPPN1PP/R4RK1 w - - 0 1

1.Qxf8+! Kxf8

If 1...Bxf8 White mates immediately with 2.Bxf7#

2. Rxf7+ Kg8
3. Rg7+ Kf8
4. Rg8#

Or 3...Kh8 4. Rg8#

So with proper play by Black, White will have to settle for a mate in 4.

Problem 4 - Black To Play

1Q1nb3/p3k1pp/3p1p2/1B1p4/PK1B4/4P3/5PPP/2r5 b - - 0 1

1...Nc6+
2.Bxc6 Rb1+
3.Ka5 Rxb8

This is the main line. Black skewers the White queen, and is now up the exchange. However, White isn't forced to take the knight on move 2, but if he doesn't, the result is a bit worse.

2.Ka3 Nxb8
3.Bxa7 Bxb5
4.axb5 Nd7

In this line, White is down an entire Rook. So it's best to let the queen skewer go through.

Endgame of the Week

8/5k2/5P1p/5K1P/8/8/8/8 w - - 0 1

The answer to the question "whose move is it?" is very important in the endgames. Sometimes you get a position that would be completely awesome and you can win it easily - if only it were the other guy's move, because then he'd have to retreat, or do something equally disadvantageous.

Of course, we all know the word for this, when it's your move, but you really don't want to me because any move you make will fatally destablize your position: zugswang.

This is one of those positions.

First, with White to move, he won't be able to directly march his king up and force Black out. If he tries that, it'll be stalemate:

1.Ke5 Kf8
2.Ke6 Ke8
3.f7+ Kf8
4.Kf6 stalemate

If Black moves first:

1...Kf8
2.Kg6 Kg8
3.Kxh6 Kf7
4.Kg5

White should not be hasty with 4.Kh7 Kxf6 and now he won't be able to move his king off of the 'h' file to make room for his pawn to queen.

4...Kf8
5.Kg6 Ke8
6.f7+ Ke7
7.h6 Ke6
8.f8=Q and wins

So, given that it's a win for White if it's Black's move, can White force this same starting position, only have it be Black's move?

Yes, he can, and this is how he does it:

1.Ke5 Kf8
2.Ke4

So White doesn't advance his king just yet. He has to bide his time, and now it's Black's move:

2...Ke8

Black must also bide his time. Wrong is 2...Kf7 because 3.Kf5 and now White has achieved his objective: it is now Black's move, and it's the starting position.

3.Kf4 Kf8

Still biding...

4.Ke5 Kf7

And now Black must bring his king up to prevent the incursion: 4...Ke8 5.Ke6 Kf8 6.f7 Kg7 7.Ke7

5.Kf5

But now, we're back at the starting position, and would you look at that, it's Black's move. So now he has to back off, and White can push forward:

5...Kf8
6.Kg6 Kg8
7.Kxh6 Kf7
8.Kg5 Kf8
9.Kg6 Ke8
10.f7+ Kd7
11.f8=Q and wins

White's method of forcing the position with Black to move is called "triangulaton", because White must move his King in a triangular pattern to lose the tempo. Sometimes in endgames between grandmasters, you see both players making seemingly aimless king moves, but what they're doing is trying to jockey for the position and the tempo that is most favorable.

Hope to see you all next week!

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Note: that cryptic line of letters and numbers you see underneath each board diagram is a representation of the position in what is known as "Forsyth-Edwards Notation", or F.E.N. It's actually readable by humans. Most computer applications nowadays can read FEN, so those of you who may want to study the position, you can copy the line of FEN and paste into your chess app and it should automatically recreate the position on its display board. Or, Windows users can just "triple click" on it and the entire line will be highlighted so you can copy and past it into your chess app.

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So that about wraps it up for this week. Chess thread tips, suggestions, bribes, rumors, threats, and insults may be sent to my yahoo address: OregonMuse little-a-in-a-circle yahoo dott com.

posted by OregonMuse at 05:00 PM

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