[blind-chess] Spoiler Alert: Problem WAC094
- From: "Paul Benson" <paul.benson@xxxxxxxxxxxxxxx>
- To: <blind-chess@xxxxxxxxxxxxx>
- Date: Mon, 27 Aug 2012 16:15:25 +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: Three pawn islands, and a piece for a pawn down. One might think that
white would probably be content to draw this game. However, inaccurate play by
black over the next few moves, could lead white to believe this game could be
won. All of the white pawns are isolated, which means protection must be from
either the white king or queen. The c4 pawn is passed, but since black has
king, queen, and knight, on the queenside, this pawn will not progress easily.
The e3 pawn will also find progress very difficult, having an opposing, and
thus blocking, black e5 pawn. The h5 pawn is a distant passed pawn. The word,
"distant", refers to the pawn location with respect to the opposing black king,
in this case 6 files away on the queenside. The h5 pawn should be guarded at
all costs, this pawn is going to be very difficult for black to prevent from
advancing. White will need this pawn to deflect black pieces over to the
kingside,in order to prevent the h-pawn's attempt to promote. Should black
respond in this way, then white can consider advancing the c-pawn. In this way,
white will be trying to keep black pieces tied down to simultaneously
preventing the advance of both pawns, and at least hold the position as a draw
.
Black: Two pawn islands, and a knight for a pawn up. One might think that black
would be trying to win this game. However, to do so, black must find a
defensive means to halt the advance of the white passed c-pawn and distant
passed h-pawn. The a6 pawn is passed, and it is this pawn which black will
advance, in between restraining the white pawns, and avoiding a perpetual check
assault from the white queen. Not easy at all. The e5 pawn is blocked, and will
quickly be doubly attacked, as the white king advances to the e4 square. The
king has little protective cover, and will have to find a means to prevent a
perpetual attack from the white queen. The queen is well placed on b2, offering
protection to the e5 pawn, and also being located a, "knight's jump", from the
white king, restricting it's mobility. The knight on a4 is unprotected, but is
actively placed for attacking purposes. The knight is 6 files away from the
white h5 pawn, and will have much difficulty in trying to prevent the advance
of that pawn
.
** Hints section, 5 hints
.
Hint 1, to find the key move
.
Sometimes a small investment can reap the largest reward
.
Hint 2, to find the key move
.
Even the most powerful piece can be deflected
.
Hint 3, to find the key move
.
Quote from R. J. Fischer: "Best by test", and it holds true here
.
Hint 4, to find the key move
.
Amazingly, there is a potential mate in 2 moves here
.
Final hint, to find the key move
.
A kleptomaniac visitor to Buckingham Palace with a penchant for cutlery was
apprehended. They had "acquired" 2 royal soup spoons, 2 royal knives, and 2
royal dessert spoons. What did the thief miss?
.
** Proposed solution to WAC094
.
This might appear to have the prospects of being a long and hard struggle on
both sides. However, the white royalty can be drawn into an unfortunate
formation, quickly simplifying matters. Black takes advantage of the restricted
mobility of the white king, and plays, 1. ... e4+, and since the white king has
no flight squares, this pawn must be captured in either of 2 possible ways
.
Variation A: White replies with, 2. Qxe4, and black now concludes matters with,
2. ... Nc5+ mate. Again, the location of the black queen on b2, being a,
"knight's jump", away from the white king proves a powerful positional trump
card for black. This black queen and white king formation, leaves the king with
5 flight squares covered by the black queen, they are: c2, d2, e2, c3, and d4.
A centralised king has 8 squares surrounding the square on which it is located.
Here, with the white king on d3, 2 of the remaining flight squares are occupied
by white pawns. So, in the initial position of the problem, the white king had
only one legal flight square, that is e4. When black sacrificed the e5 pawn,
the final flight square of e4, became occupied by the white queen. All that was
then needed was a check from a piece which can not be blocked. The knight is
such a piece. Perhaps an unkind annotator might comment on the mating formation
with, "Just as well it was mate, otherwise white would have lost the queen"
.
Variation B: White captures with, 2. Kxe4, and yet again the white royalty has
been drawn into a formation in which a knight fork is devastating. Black plays,
2. ... Nc3+, another royal fork. White could struggle on with, 3. Kf5, but
after, 3. ... Nxd5 4. cxd5, black has many ways to win. Perhaps the simplest
is, 4. ... Qf2+ 5. Ke4 Qh4+, with the following general ideas. Firstly, the
black queen will eliminate the white h5 pawn. Secondly, centralise the black
king, ready to restrain and then capture the white connected passed pawns.
Lastly, advance the a6 pawn, which will deflect the white king to the a-file.
The white pawns will then fall to either the black king or queen, as appropriate
.
** Condensed proposed solution
.
1. ... e4+ 2. Qxe4 Nc5+ mate
.
** Other tactical variations considered, and rejected
.
Option 1: If black tries to prevent the advance of the white h5 pawn with, 1.
... Qh2, also protecting the black e5 pawn, there is a rude awakening. White
plays, 2. Qd7+, demonstrating why king's need protective cover in endings where
queens are present. White has just forked black's king and the unprotected
black a4 knight. After, 2. ... Kb6 3. Qxa4 Qxh5, an ending with queen and 2
pawns each has arisen. White might have better prospects, as the black e5 pawn
could become a target for a double attack from the white queen and king. If
black tries to prevent this, by placing the queen on the white 4th rank, then
the white queen can combine with the passed c4 pawn, to create serious threats
of advancing the pawn to promote. Black has slightly more problems than white,
and will have many ways to go wrong
.
In practice, queen and pawn endings are probably misplayed more often by
untitled players than any other type of ending. This is because a centralised
queen located on any of, d4, e4, d5, e5, with full mobility on an empty board,
has 8 directions in which to move, and has access to no less than 27 squares.
With so many options to consider, and so many options for the reply to
consider, it should be obvious that the potential permutations quickly become
astronomical. Sifting out the good ideas from the bad, becomes a serious mental
aerobatic challenge
.
Option 2: Black tries to infiltrate further with the queen, 1. ... Qc3+, but
after, 2. Ke4, black has forced the white king to create a double attack on the
e5 pawn. Furthermore, the black knight is still vulnerable to a potential,
Qd7+, fork from white. Black has not made any progress, but instead made
matters worse. There is also the possible advance of the white h5 pawn, which
could soon receive support from the white king, for black to prevent
.
** Alarm bells
.
1. The "knight's jump" formation of a king and an opposing queen can be very
powerful. Note how the white king had restricted mobility because of the
closeness of the black queen, and such a formation should be given serious
consideration to reduce the options of flight during a king-hunt
.
2. The white king and queen were both on light squares, and close together.
This should raise concern over potential forks, should there be an opposing
knight close by. The danger will significantly increase if the royal pair have
little pawn protection
.
3. The knight is a short range piece. What it lacks in power over distance, is
compensated for by it's ability to dance a
. round, creating a series of new threats with each move, as it constantly
alternates between light and dark squares
.
4. It would appear this game could last for many more moves. Just because one
thinks a long game is in prospect, does not rule out the possibility of an
immediate winning tactic. Constant vigilance for a quick finish is necessary at
all times, irrespective of the general assessment of how long a game might last
.
Paul Benson.
-----Original Message-----
From: R Dinger - Email Address: rrdinger@xxxxxxxxxx
Sent On: 21/08/2012 16:00
Sent To: chess - Email Address: blind-chess@xxxxxxxxxxxxx
Subject: [blind-chess] Problem WAC094
Good Morning Puzzlers,
Another WAC series problem.
This problem is from Mario Lang's puzzle web page at:
http://delysid.org/chess/epd.cgi
Problem WAC094
Black to move
FEN Problem Setup:
8/
k7/
p7/
3Qp2P/
n1P5/
3KP3/
1q6/
8
b - - 0 1
Short Algebraic Problem Setup:
White: Kd3, Qd5, Pc4, Pe3, Ph5
Black: Ka7, Qb2, Na4, Pa6, Pe5
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