[blind-chess] Spoiler Alert: Problem WAC093

  • From: "Paul Benson" <paul.benson@xxxxxxxxxxxxxxx>
  • To: <blind-chess@xxxxxxxxxxxxx>
  • Date: Mon, 20 Aug 2012 13:27:31 +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. The shattered queenside pawn structure is that 
typical of the Winawer Variation of the French Defence. White will have to play 
actively with pieces during the middlegame, and if no advantage is found, these 
pawns will be weaknesses in the endgame. The king is in no immediate danger, 
and should queens be exchanged in the next few moves, might choose to forego 
castling and remain in the centre of the board. The queen has made a typical 
Winawer Variation invasion on g7, creating some tactical possibilities. She is 
unprotected and challenged by the black queen, a decision is needed by white 
here. The a1 rook is ready to move to a semi-open file, the b-file seems 
logical. The h1 rook is several moves away from development. Both bishops have 
good options for development, the dark square c1 bishop has no black 
counterpart, and will have much control over the dark squares for a while to 
come. The g1 knight is presently not advised to move to the f3 square, it's 
most favourable post for development, since black could trade knights, and give 
white a poor kingside pawn structure, as long as the black e5 knight remains 
where it is
. 
Black: Three pawn islands. The c-file will become a point of activity for black 
in the middlegame, the doubled white c-pawns being targets to attack. The 
h-pawn is isolated, but will not be an weakness until the endgame. The king has 
several pieces nearby, suggesting safety from the invading white queen. The 
queen on f6 is challenging the white queen, seeking her removal from the black 
kingside, and is also giving an x-ray defence to the h8 rook. The a8 rook is a 
couple of moves away from contributing, the c-file beckons. The h8 rook will 
need several moves to develop, and depending on how play continues, could be 
placed either on the semi-open g-file, or consider doubling down the c-file. 
The c8 bishop has restricted development options, due to the typical French 
Defence pawn structure. The e5 knight appears to have a pleasant post, however 
it is not secure on e5, and can be soon pushed away. The g8 knight is presently 
immobile, being tied down to defending the queen
. 
** Hints section, 5 hints
. 
Hint 1, to find the key move
. 
Is there an overloaded piece to be exploited?
. 
Hint 2, to find the key move
. 
Paradoxically, defending can be attacking
. 
Hint 3, to find the key move
. 
Is it time for some development?
. 
Hint 4, to find the key move
. 
Winning ideas are not always tactically aggressive
. 
Final hint, to find the key move
. 
Royalty and the Church are in agreement here
. 
** Proposed solution to WAC093
. 
White can seriously increase the pressure on black, by apparently offering a 
piece with, 1. Bh6. Yes, the h6 bishop protects the white queen, but surely 
this bishop is doubly attacked, by the black queen and the g8 knight? Tactics 
save the day for white. Black has 7 replies to consider, 3 of which are 
immediately catastrophic
. 
Variation 1: This is chosen as the main line for the solution, simply because 
it produces an interesting mating pattern. Black plays, 1. ... Ng4, refusing to 
take the bait, and instead attempting to achieve piece coordination on the 
kingside. Of course, this knight can be captured with, 2. Qxg4, after which 
black can either play safe with, 2. ... Nxh6, material equality is 
re-established, and white has lost the initiative, or, instead black can try 
the much riskier, 2. ... Qxc3+ 3. Ke2 Qxa1, but now, 4. Bg7, forks the black 
queen and rook, and white will have a material gain, but an uncomfortable king 
for a while
. 
. So, with, 1. ... Ng4, the knight is immune from capture, and black is also 
placing a 3rd attack on the once-defended white h6 bishop. This would seem to 
resolve matters on the kingside dark squares for black, as not only is the h6 
bishop seriously threatened, the f2 pawn has suddenly become a target of a 
double attack by black. It might seem as if white can only relieve the pressure 
with a queen trade. This is not the case, the black knight in trying to resolve 
matters on the kingside, but has deserted the queenside, and this offers white 
a clever win with, 2. Bb5+, which leaves black with 3 replies. Firstly either, 
2. ... Kd8, or, Ke7, both of which are met with, 3. Bg5, pinning the black 
queen to the black king, white wins. Instead, after, 2. Bb5+, black can 
interpose with, 2. ... Bd7, and white must do something about the kingside. 
However, the black bishop on d7 has shut in the black king, the d7 square was a 
potential flight square. So, white plays, 3. Qf8+ mate. Had the black e5 knight 
not wandered into the kingside, with the best of intentions of course, then 
that knight would have had the option to block a check from the white f1 
bishop, by retreating to c6, and the pattern of incarceration of the black king 
could not have been created
. 
Variiation 2: Black tries, 1. ... Qxh6, but this removes the black queen's 
previous x-ray defence of the h8 rook. Simply, 2. Qxh8, white is an exchange 
up, and black also has the problem of both knights being attacked by the white 
queen. The only reply to avoid further immediate material loss is, 2. ... Qg5, 
leaving white to decide which way to win a piece. The black queen is 
overloaded, protecting knights on e5 and g8, and as such if she can be attacked 
by white, which would deflect her from the g5 square, then one of the black 
knights will fall. White has 3 moves here. The simplest is, 3. h4, also good 
is, 3. Nh3, and lastly, the slightly riskier, 3. f4, all 3 white moves forcing 
the black queen to move off the g5 square, and these deflections all win a 
piece for white. Note, after any of the 3 suggested 3rd white moves, black 
could try to meet an attack with a counter-attack. The idea is, 3. ... Ng6, and 
now both queens are attacked. However, this knight retreat has interfered with 
the black queen's backward protection of the g8 knight, and so, 4. Qxg8+, the 
white queen evades the attack with a capturing check, which will be followed by 
the capture of the black queen next move
. 
Variation 3: Black tries, 1. ... Kd7, attempting to remove the king from the 
active white pieces. White plays, 2. Qxf6 Nxf6, and now, 3. Bg7, forking the 
black f6 knight and h8 rook. There are no tricks for black here, white is 
winning either the f6 knight or the h8 rook
. 
Variation 4: Black plays, 1. ... Qxg7 2. Bxg7, and white forks the black e5 
knight and h8 rook. If now, 2. ... Ng6 3. Bxh8, is simplest. White is an 
exchange up and is essentially winning, black has no compensation for the 
material
. 
Variation 5: Black plays, 1. ... Ke7, protecting the queen on f6, which means 
the white h6 bishop can now be captured by the g8 knight. Sadly, black has 
walked the king into dark-squared doom, white plays, 2. Bg5, pinning the black 
queen to the king, white wins
. 
Variation 6: Black could blunder with, 1. ... Nxh6, and this knight capture 
leaves the black queen defenceless, so, 2. Qxf6, and white has won a queen for 
a bishop, white is winning
. 
Variation 7: Black tries, 1. ... Bd7, developing and intending to move the king 
to queenside safety. This is well motivated, but is tactically flawed. This is 
an awful blunder, as black has just denied his king it's only flight square. 
White plays, 2. Qf8+ mate
. 
** Condensed proposed solution
. 
1. Bh6 Ng4 2. Bb5+ Bd7 3. Qf8+ mate
. 
** Other tactical variations considered, and rejected
. 
Option A: White could trade queens with, 1. Qxf6, and after, 1. ... Nxf6, black 
would have a lead in development. This is not particularly desirable for white, 
even though black will have to play well to contain the white bishop pair in 
the coming middlegame. By exchanging queens, pressure has been removed from 
black, and a winning opportunity has been overlooked
. 
Option B: White retreats with, 1. Qg5, which gains white nothing. Black could 
play, 1. ... Qxg5 2. Bxg5, and now, 2. ... f6, and black can slowly proceed 
with development. White has the bishop pair in a position with pawn structure 
imbalances, slightly advantageous but not decisive
. 
Option C: White tries a different retreat with, 1. Qg3, which does at least 
leave white the option of, Bg5, to gain some good dark square control. The 
position has good imbalance, white has the bishop pair but a weakened queenside 
pawn structure. There are opportunities for both sides, the player with the 
better positional understanding would be expected to handle this better, and 
slowly begin to make slight gains as the game proceeds
. 
** Alarm Bells
. 
1. Overloading can apply to protecting squares as well as protecting material. 
The g8 knight was protecting the queen, and probably thought it had the h6 
square covered as well. Clearly, it did not
. 
2. Black chose to demolish the white pawn centre of a French Defence, instead 
of completing development. The white pawn centre was always going to be there, 
the early demolition could have waited until development was complete. By 
delaying central demolition, black would also have the advantage of having 
white committing the minor pieces, before knowing black intended to attack the 
centre
. 
3. Black has traded bishop for knight on c3, hoping to exploit the weaknesses 
later in the game. This is fine, however giving the white bishops such 
opportunities, so soon in an open position, seems undesirable
. 
4. The white queen has embarked on an early invasion, before developing the 
minor pieces, this style of play is double-edged and consequently dangerous to 
the unwary. If theory shows this plan can be played, then one could research to 
determine if this suits your style of play. However, if you have no theoretical 
knowledge of playing early with the queen, then perhaps completing development 
is a safer plan
. 
5. Bishops are long-range pieces. Black has traded one off, and the other has 
only one move, in contrast, the white bishops have good potential mobility. 
These factors encouraged white to search for a means to exploit the advantages
. 
Paul Benson. 

-----Original Message-----
From: R Dinger - Email Address: rrdinger@xxxxxxxxxx
Sent On: 14/08/2012 16:19
Sent To: chess - Email Address: blind-chess@xxxxxxxxxxxxx
Subject: [blind-chess] Problem WAC093

Good Morning Puzzlers,

This time a tactics problem continuing the WAC series of problems.

This problem is from Mario Lang's puzzle web page at: 
http://delysid.org/chess/epd.cgi

Problem WAC093

White to move

FEN Problem Setup:
r1b1k1nr/
pp3pQp/
4pq2/
3pn3/
8/
P1P5/
2P2PPP/
R1B1KBNR
 w - - 0 1

Short Algebraic Problem Setup:
White: Ke1, Qg7, Ra1, Rh1, Bc1, Bf1, Ng1, Pa3, Pc2, Pc3, Pf2, Pg2, Ph2
Black: Ke8, Qf6, Ra8, Rh8, Bc8, Ne5, Ng8, Pa7, Pb7, Pd5, Pe6, Pf7, Ph7

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