Again, this is a useful pattern to keep in mind and hopefully you'll recognize it when you see it.

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Solutions Update:

Black Mates In 1

1...Nd3#

Note that this move simultaneously uncovers an attack by the bishop and covers the flight square at e1, so there is no escape for the White king.

White Mates in 3

The key move is:

1.Bf6

which leaves Black with only one move

1...gxf6

2.Kf8

Closing in for the kill. Again, there is only one possible Black reply.

2...f5 followed by

3.Nf7#

White Mates In 5

1.Qf7+ Kh8

If 1...Kh7 then 2.Qg6+ Kg8 3.Rf8+ Kxf8 4.Qf7#

2.Qe8+ Kh7
3.Qg6+ Kg8

If 3...Kh8 then 4.Rf8#

4.Rf8+ Kxf8
5.Qf7# 1-0

Endgame Of The Week

The decision tree for this is rather complicated, but the main line goes like this:

1.Bc4+ Kxc4
2.Nd2+ Kd3
3.Nf3!

and White has now achieved the piece configuration similar to my diag. 'a'. All he has to do shuffle his knight between the f3, g1 and h3 squares, and there's nothing Black can do to force him out. If he pushes the pawn, White happily gives up his knight for it. So the game is a draw.

But if instead of 1...Kxc4, if Black chooses, say, 1...Ke4, then what? Well, White has a couple of options, the first being 2.Bd5+. Then Black has to play 2...Kxd5 3.Nd2 Ke5 4.Nf3+ and there's the draw again. (Update: see #220)

Or, White could play 2.Nd2+ and then it's Ke3 3.Nf3! Kxf3 4.Bd5+ Kf2 5.Bxg2 with the draw.

Again, the decision tree for all the possibilities is quite complex. So for those of you who use pgn readers, here are all the lines, annotated, in pgn format. You can just copy and paste it to your pgn reader. This problem was a chess.com daily puzzle of a few days ago, and one of the commenters put together the annotated lines, and I thought his analysis was thorough and complete:

[Event "White to play and draw"]
[Site "?"]
[Date "2016.07.06"]
[Round "?"]
[White "N, N."]
[Black "N, N."]
[Result "1/2-1/2"]
[Annotator ""]
[SetUp "1"]
[FEN "8/4K3/8/3k4/8/1N1B4/6p1/8 w - - 0 1"]
[PlyCount "5"]
[EventDate "2016.??.??"]

1. Bc4+ $3 Kxc4 (1... Ke4 2. Nd2+ (2. Bd5+ Kxd5 (2...Ke3 $4 3. Bxg2 {and White wins}) 3. Nd2 Ke5 4. Nf3+ {Draw}) 2... Ke3 3. Nf3 $3 Kxf3 (3... Kf2 4. Kf6 {Black can make no progress.} g1=Q 5. Nxg1 Kxg1 {Draw}) 4. Bd5+ Kf2 5. Bxg2 {Draw}) (1... Ke5 2. Nd2 $1 g1=Q $4 (2... Kf4 3. Nf3 $3 Kxf3 (3... Kg3 4. Kf6 Kf2 5. Kf5 g1=Q 6. Nxg1 Kxg1 {Draw}) 4. Bd5+ Kf2 5. Bxg2 {Draw}) 3. Nf3+ Kf4 4. Nxg1 {White now wins.}) (1... Kc6 2. Nd4+ Kc5 3. Nf3 Kxc4 4. Ng1 {Draw for the same reason as in the main line.}) 2. Nd2+ Kd3 3. Nf3 $1 {This is a draw because black can't stop the knight from going to either g1 (blocking the pawn) or h3, f3, and e2 (guarding the promotion square where the knight will gladly give itself up if the pawn promotes).} 1/2-1/2

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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.

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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 Open Blogger at 04:45 PM

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