[blind-chess] Spoiler Alert Problem WAC032

From: "Paul Benson" <paul.benson@xxxxxxxxxxxxxxx>
To: <blind-chess@xxxxxxxxxxxxx>
Date: Mon, 13 Sep 2010 11:19:19 +0100
Hello all,
.
This posting is divided into various parts. You can jump to the headings of the 
sections by search/find for **, a pair of asterisks
.
** Positional evaluation of the problem
.
White is somewhat passive here. The white king is safe, apart from a potential 
back rank mate, though there is a knight on g3 which at the moment could drop 
back to f1 if needed. Pawn structure is fine. The queen is on an open file. The 
g3 knight is putting pressure on the e4 black pawn, this ties down the black 
knight to defending that pawn
.
Black is slightly more active. No pawn weaknesses, the king has a flight square 
in g7, to escape any back rank checks. The queen is seems to be active on c5, 
but is not really doing much. Lastly, the f6 knight is tied down to defending 
the e4 pawn, and is itself undefended
.
So, in positional terms, who is better here? I would say, it's about equal. If 
white wishes, the knight could regroup to d4 via e2, to obtain an outpost where 
it is safe from pawn attack. If white did that, then the black knight would be 
free to land itself on d3. Neither of these plans actually do much, one would 
on positional terms, expect this to be drawn soon
.
.
** Hints section, 4 hints
.
** Hint 1, to find the key move
.
Any move that forces a response, should be examined a little further than one 
would for other moves
.
** Hint 2, to find the key move
.
Did I say forcing move?Perhaps one forcing move could be followed by another, 
and perhaps even more
.
** Hint 3, to find the key move
.
Lightning does not strike twice in the same place, unless the lightning is 
forked
.
** 4th and final hint, to find the key move
.
White gets into a king and pawn ending in just 4 moves
.
** Proposed solution to WAC032
.
The winning sequence is a forcing one, and the forcing move that can not be 
ignored is a check. 
.
So, 1. Qd8+ and black has 3 replies. Two moves lose the f6 knight, 1. ... Ne8 
2. Qxe8+, or 1. ... Qf8 2. Qxf6, both white wins. So, 1. ... Kg7, and now a 
difficult move to find. White 2. Qxf6+, and the black reply is again forced, 2. 
... Kxf6. White has drawn out the black king to a point where the knight can 
fork king and queen. So, the lightning fork hits black, 3. Nxe4+ Ke5 4. Nxc5 
bxc5, and white has snatched a pawn in the forking capture. For completeness, 
5. Kf1 Kd5 6. Ke2 Kc4 7 Kd2 and any black king invasion is halted
.
** Condensed proposed solution to WAC032
.
1. Qd8+ Kg7 2. Qxf6+ Kxf6 3. Nxe4+ Ke5 4. Nxc5 bxc5 5. Kf1 Kd5 6. Ke2 Kc4 7. Kd2
.
** Other tactical variations considered, and rejected 
.
The only other try for white is to attack the e4 pawn, with either 1. Qb1 or 
Qa4, but this pawn can not be captured. Black could try 1. ... h5, and now 2. 
Nxe4 loses. Black plays 2. ... Nxe4 
3. Qxe4 Qc1 mate. Showing how the e4 pawn is indirectly defended by a tactical 
threat
.
** Alarm bells
. 
1. Black failed to realise the potential danger of the squares c5 and f6, being 
connected to each other by a knight move, that is from the e4 square
.
2. The square e4 was contested by the black knight, so black became complacent 
as to any white knight moves to this square, since the black knight was 
apparently covering it
.
Paul Benson.

-----Original Message-----
From: R Dinger - Email Address: rrdinger@xxxxxxxxxx
Sent On: 10/09/2010 18:40
Sent To: chess - Email Address: blind-chess@xxxxxxxxxxxxx
Subject: [blind-chess] Problem WAC032

Good Morning Puzzlers,

This problem is from Mario Lang's puzzle web page at 
http://delysid.org/chess/epd.cgi
 and is reported to be from Fred Reinfield's book "Win At Chess" 1958.

Problem WAC032

White to move

FEN Problem Setup:
6k1/
p4p1p/
1p3np1/
2q5/
4p3/
4P1N1/
PP3PPP/
3Q2K1
 w - - 0 1

Short Algebraic Problem Setup:
White: Kg1, Qd1, Ng3, Pa2, Pb2, Pe3, Pf2, Pg2, Ph2
Black: Kg8, Qc5, Nf6, Pa7, Pb6, Pe4, Pf7, Pg6, Ph7
[blind-chess] Spoiler Alert Problem WAC032

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