[blind-chess] Spoiler Alert Problem WAC030
- From: "Paul Benson" <paul.benson@xxxxxxxxxxxxxxx>
- To: <blind-chess@xxxxxxxxxxxxx>
- Date: Mon, 6 Sep 2010 03:55:10 +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
** Houston, we have a problem
.
I am having problems finding a conclusive variation for white. I suspect the
diagram given on the source web site is slightly incorrect. Alternatively, it
could be that the web site may have correctly reproduced from the book, but the
diagram in the print edition is incorrect.. I shall therefore alter the diagram
to what I believe it to be. So, I propose you place that pawn sitting on a2, on
a much better square, that is a3, where it protects the b4 pawn. My
contribution here is based on this re-positioning
.
** Positional evaluation of the problem
.
White has no pawn weaknesses, and the king is perfectly safe. The g2 bishop is
presently blocked by it's fellow knight on e4, but since that knight is
attacked, the power down the long diagonal will quickly be regained. The white
rooks are centralised. The d1 rook is aiming at the d6 pawn, and the e1 rook,
though seemingly skulking behind the e2 pawn, can help to break in the centre
with e4 if desired. The white queen seems to be tied down to defending the a3
pawn
.
I suspect black has been pressing for the initiative, and is prepared to accept
some weaknesses in the position, hoping for compensation in active play. Black
has 3 pawn islands, this in itself is not necessarily bad. It just means he
will have to work hard at the board, analysing variations in which activity can
create sufficient threats, such that white has no time to gang up on the
weaknesses. The black king appears to have lost the protection previously given
by the dark-squared bishop, now in retirement. The last game move must have
been pawn f5. This seems to sum up black's entire approach. He is playing
actively, hoping any potential lines of entry to his king will not be fatal.
Black is trying to play on the kingside, the queenside, and a little in the
centre. You really need to be sure you know what you are doing to be this
ambitious. The black knight is well established on c4, where it can not be
moved by a white pawn. The bishop on a6 is offering support, and potential
attacking power towards .the white centre. The black queen is located on a file
where it is potentially attacking the e2 pawn, but on the other hand, is also
on a file where there is a white rook, lurking behind a pawn. She may be
exposed later, if white breaks out with an e4 push. I would prefer that rook on
f8 to be supporting the pawn on d6, offering more protection than is necessary.
This concept of over-protection is a very useful one to understand.
.
If I can explain it in another way. Imagine a prison-door always needs 2 guards
to protect it. If there are 2 guards, as required, then neither can leave their
post. If however, there were 3 guards protecting the door, then any one of the
3 guards may depart for business elsewhere, and return later. Upon return,
either of the 2 who remained at their post, can move away if they wish. In
chess terms, that d6 pawn is defended by a knight and queen, neither of which
can move away, thus 2 pieces are tied down. If black had played Rfd8, instead
of f5, then the overprotection would come into play. It means that all 3 pieces
offering protection are all free to move away without losing the pawn. So,
instead of f5, black Rfd8 would have liberated the knight and queen from
continual protective duty, and all 3 over-protectors could now be regarded not
just as defenders, but also potential attackers
.
** Hints section, 3 hints
.
** Hint 1, to find the key move
.
How many x-ray attacks are present here?
.
** Hint 2, to find the key move
.
Can you find a way for an x-ray attacker to strike?
.
** Hint 3, to find the key move
.
Unprotected pieces, however well hidden from attack they may appear to be, are
not always so.
.
** Proposed solution to modified WAC030
.
The white knight gives itself up, to unleash the full power of the white queen.
So, 1. Nxd6 Nxd6 2. Qxc6, and the queen attacks the loose bishop on a6, and
puts a second attack on the
once-only protected d6 knight. Black must lose a piece now, and has just lost
those 2 weak pawns as well
.
Black can try 2. ... Bb5, but now 3. Qxd6, leaves black in a fix. White is 2
clear and safe pawns up, black can retreat the queen, but the white rooks will
invade, and white has a light squared bishop to get at the a5 pawn much later.
.
Now back to the start position, and I will show why I suspect the white pawn
sits on a3, because if it were on a2, black has a resource. Place the pawn back
on a2 for this analysis, as in the web site diagram
.
So, 1. Nxd6 Nxd6 2. Qxc6, and now black improves with 2. ... Bb7, forcing into
an ending. After 3. Qxd6 Qxd6 4. Rxd6 Bxg2 5. Kxg2, and now black has 5. ...
Rxb4, regaining a pawn. This ending is still favourable to white, but is
nowhere near a clear win, if it is a win at all. White could tie black down
with 6. Ra6, but then 6. ... Rfb8, intending black Rc4 to still protect a4, and
allow the b8 rook to invade at b2, seems to be active enough to hold a draw. It
is this 5. ... Rxb4 sting in the tail, that leads me to think the pawn is on a3
.
** Alarm bells
.
1. Sometimes, discretion is the better part of valour. Black in playing f5 was
too optimistic. Perhaps black gets some fantastic wins by playing like this,
but just not today
.
2. Over-protecting a weakness frees up all protectors, for defence or attack
elsewhere
.
3. Unprotected pieces, such as the a6 bishop, should attract attention, is
there a way to capitalise on it?
.
4. Just because the black knight sat on c4, shielding the c6 pawn from the
white queen, it does not mean that is a permanent arrangement.
Paul Benson.
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 WAC030
White to move
FEN Problem Setup:
1r3r2/
4q1kp/
b1pp2p1/
5p2/
pPn1N3/
6P1/
P3PPBP/
2QRR1K1
w - - 0 1
Short Algebraic Problem Setup:
White: Kg1, Qc1, Rd1, Re1, Bg2, Ne4, Pa2, Pb4, Pe2, Pf2, Pg3, Ph2
Black: Kg7, Qe7, Rb8, Rf8, Ba6, Nc4, Pa4, Pc6, Pd6, Pf5, Pg6, Ph7
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