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Jan-21-11
 | | scormus: Looks like the regular POTD crowd have beaten me to it again, and I was so pleased with myself for seeing it too ;) Yes, I relaise the final skewer is neat, but I agree 35 ... Qxc3 is the cleaner win. In fact how I hit on 34 ... Bh3+ was it was a way to stop WQ from taking it after the immediate ... Qxc3, and of course BK cannot take it on h3. |
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| Jan-21-11 | | agb2002: I didn't even consider the obvious 38.Qxd3. It must be the 'missed trivial move disease' ... |
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| Jan-21-11 | | David2009: N Delgado vs L Dominguez, 2005 Black 34...? Building on <Patriot>'s sound advice over a series of posts and months, I am trying to approach these puzzles in a more systematic way. The challenge is two-fold: find the pragmatic solution and the actual solution. The pragmatic solution is 34...Qe5 winning a Pawn safely. This is what I would play in 5/15 chess, my standard time limit in Internet chess (5 minutes starting capital than 15 s/move income). One has to avoid unnecessary weakenings, wild speculations (34...Qxc3?? gives White at least a perpetual check) and living above one's income (moving systematically at slower than 15 s/move). In general: the best is the enemy of the good. Here, the good is the enemy of the best. Black promotes the d Pawn starting 34...Bh3+ and there is no defence. Even refusing the sacrifice with 35 Kf3 Qxf4+ 36 gxf4 fails to 36...Bg4+ Time to check the game.
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Serious flaws in today's analysis:
(A) My "pragmatic" solution actually LOSES: 34...Qe5 35.Qxe5! dxe5 36.Kf3 (the move I had missed) Kg6 37.Ke3 Kf6 38.Na4 and Black's Pawns are sitting ducks; (B) My "good" solution 34...Bh3+ 35 Kf3 35...Qxf4+? would dissipate Black's entire advantage. This isn't too serious since I have sacrificed nothing and am free to look for better continuations. Setting up the position in Crafty End Game Trainer with colours reversed, the colours-reversed puzzle position is: 
click for larger view
EGT link: http://www.chessvideos.tv/endgame-t... Against 35...Qxc3 Crafty EGT plays the colours-reversed equivalent of 36.Na4 to reach (in normal colours) 
click for larger view
and I leave to fellow-kibitzers the pleasure of discovering a neat Black win from this position. You can test your ideas by playing it out using the link given above: you are white, drag and drop the move you want to make. |
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| Jan-21-11 | | gofer: I thought that 34 ... Bh3+ 35 Kf3 Bg4+ 36 Ke3 Qxc3 37 Qf5+ f5 38 Qxd3 was okay for white, so I avoided it completely. I didn't see the queen trap
that was available - which was really quite a find by black... ...with my line I can win pretty easily, white sacs the knight into a losing
end game, but still the game continuation was really very nice! Have a play with Crafty EGT (colours reversed) yourself and see how far you get... http://www.chessvideos.tv/endgame-t... On that note, <M. Hassan> found one of the ways for black to make his life very difficult in this position. The key point is that the black LSB must stay on the c8-h3 diagonal to stop stalemate threats after Qf5+ as g6 cannot be played. So playing Bg2+ at any point is not advisable if the white queen is still on the board! <M.Hassan: 34 ... Bh3+ 35.Kf3 Bg2+ 36.Ke2 Qxc3 37.Qf5+ Kg8> 
click for larger view<38 Qc8+ ...> and suddenly black is in trouble!!! |
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| Jan-21-11 | | Fuegoverde: 34 ...Bh3+, 35 Kf3 others loose quikcly
35... Bg4+, 36 Ke3 or else the pawn is unstopable, now 36...Qxc3, this is as far as I can see, black can avoid the perpetual checks Qe4+ Qe8+ with ...g6 and it looks black has a winning position. |
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| Jan-21-11 | | patzer2: For today's Friday puzzle position, the combined decoy and deflection sham sacrifice offer 34...Bh3+!! gives Black several ways to win. If 35. Kxh3, then simply 35...Qxf4 36. gxf4 d2  allows the pawn to promote with decisive material advantage. After 35. Kf3, Black's 35...Bg4+ won easily enough in the game continuation when in the final position the forced 40. Kc4 leads to a winning skewer with 40...Be2 . My own solution after 35. Kf3 was simply 35...Qxc3 with an overwhelming attack. For example after 34...Bh3+!! 35. Kf3 Qxc3!, Crafty's 36. Na4 is refuted by 36...Qc2 with the passed pawn creating a decisive threat (e.g. 37. Qe4+ f5 38. Qd4 Qxa4+ ). P.S.: Since the combination with 34...Bh3+!! potentially involves the decoy, deflection, passed pawn, skewer and mating attack tactics, for now I'll put it in my "combined operations" collection. |
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| Jan-21-11 | | emunk96: in Sicilian, i thought that pushing the king pawn two squares is not good as the d6 pawn will weak but black showed that the weak d6 pawn helps... |
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| Jan-21-11 | | suvhasis: I am not so sure...
After Black plays 36 ..... Qxc3,
What if White replies with
37 Na4 ?
Seems that would work out to be a satisfactory defence. Black ends up losing the pawn since White can then followup with Qe4+ (Black then does not have the handy Qe1+). Just a thought. I think white could have emerged from the situation undamaged. |
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| Jan-21-11 | | CHESSTTCAMPS: Black has a bishop for a knight and an advanced d-pawn that is two squares from promotion. Only the white queen is currently in position to stop the pawn; the white king is just outside the square. A promotion-enabling combination is in the works. The first move that occurred to me on seeing the position is very strong. 34... Bh3+!
This forcing move releases the BQ from defense of the bishop (with gain of tempo) so that it can support the ascending pawn. Also, the king is flushed out of the pocket. 35.Kf3 (otherwise 35...Qxf4 36.gxf4 d2 wins) Qxc3
Of course not 35... Qxf4+?? 36.gxf4 and the d-pawn is stopped. Now black threatens 36...d2+ 37.Ke2 Bg4+ winning. There is no satisfactory defense: A) 36.Qxf7 (trying for perpetual check) d2+ 37.Ke2 Bg4+ 38.f3 Bxf3+ 39.Qxf3 Qxf3+ 40.Kxf3 d1=Q+ wins. A.1) 37.Kf4 Qf6+ 38.Qxf6 gxf6 followed by d1=Q wins.
A.2) 37.Ke4 Qe5+ followed by d1=Q+ wins.
B) 36.Qc4 Qd2 (threatening Qe2+) 37.Qe4+ f5 38.Qe3 Bg4+ 39.Kf4 (Kg2 Qxe3 promotes) Qxb4+ 40.Kg5 Qe4 (d2? 41.Qe6) wins C) 36.Qe4+ f5 37.Qe3 (Qc4 transposes to B) Qc2 38.Qe8 Qd1+ 39.Kf4 Qg4+ 40.Ke3 Qe2+ wins. C.1) 37.Qe8 d2+ 38.Kf4 (Ke2 Bg4+) Qd4+ 39.Kf3 (Kg5 Qg4#) Bg4+ 40.Kg2 Qe4+ wins. C.2) 38.Nc4 Qd1+ 39.Kf4 Qg4#
D) 36.Nc4 d2+ 37.Ke2 Bg4+ wins.
E) 36.Na4 Qc2 wins.
F) 36.Qe3 Qc2 37.Qe1 (Qe4+ transposes to C) d2 wins. Time to review game and kibitzing. |
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| Jan-21-11 | | CHESSTTCAMPS: As <patzer2> and others have noted, the simple 35... Qxc3 works just as well as the game line. Crafty EGT went into my line E and simply gave up the Na4 (colors-reversed equivalent), allowing an easy win. |
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| Jan-21-11 | | VincentL: "Difficult"
The obvious start is 34.....Bh3+. Then after 35. Kxh3 Qxf4 36. gxf4 d2 and this d pawn will
queen, winning.
The only way to prevent this is with 35. Kf3. Then if 35.....Bf4+ 36. Ke3. I have little time and I cannot see an obvious continuation. Somewhere black must play
Qxc3 I think.
I am going to have to check. |
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| Jan-21-11 | | kevin86: I saw the first move and that the bishop capture would be deadly,but missed the follow up. Neat how black forces the queen into a pin. |
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| Jan-21-11 | | VincentL: Well, right idea. With a bit more time, perhaps I would have solved this to the end. Now I must rush. |
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| Jan-21-11 | | CHESSTTCAMPS: Before my last post, I had failed to notice that <David2009> had already diagrammed the position from my line E (original post):
click for larger viewAfter 36... Qc2, black has the double threat of Qxa4 and Qe2#. White has nothing better than 37.Qe4+ f5 38.Qd4 Qxa4 39.Qxd3 Qxb4 40.Ke2 Qe4+. |
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| Jan-21-11 | | gofer: <suvhasis: I am not so sure... After Black plays 36 ..... Qxc3,
What if White replies with
37 Na4 ?>
<Patzer2> has covered this... Effectively white is forced to give up Na4 and then swapping queens into a losing end game. Even if black has played
Bg4+ (after Bh3+) the bishop is not trapped black simply has to play g6 not f5 when white play Qe4+!
white has to give up a second pawn to win the bishop. Example
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34 ... Bh3+
35 Kf3 Bg4+
36 Ke3 Qxc3
37 Na4 Qc2
38 Qe4+ g6
39 Qxd3 Qxa4
40 f3 Bf5
Black is a whole bishop up and its only a matter of time until swapping queens is white's best option at which point black
has won.
41 Qd4 Qb3+
42 Ke2 Qc2+
43 Ke3 Qc1+
44 Qd2 Qxd2+
45 Kxd2 |
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| Jan-21-11 | | shishio71: I got 34... Bh3+ and that the king has to move forward or face impending doom with a queen exchange and an unstoppable pawn, but I didn't see the king going through an obstacle course a few moves later |
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| Jan-21-11 | | Patriot: Material is even but black has the advanced pawn on d3. 34...Bh3+
This is the move I really want to play, since if 35.Kxh3 Qxf4 36.gxf4 d2 -- the pawn is unstoppable. 35.Kf3
This move seems forced and should provide maximum resistance. Now moves such as 35...Bg4+ and 35...Bg2+ seem to do nothing but help the white king get closer to the pawn with 36.Ke3. 35...Qxf4+? 36.gxf4 is even worse. 35...Qxc3
This is the best move I can find as it threatens a discovered check, 36...d2+. This is also where it starts to get a little tricky, since everything is forced up to this point. White has several potential replies: Qe4+, Ke3, Nc4, and perhaps Na4. A) 36.Qe4+ g6
A.1) 37.Qf4 (threatening perpetual check) d2+ 38.Ke2 Bg4+ 39.f3 Bxf3+! A.1.a) 40.Qxf3 Qxf3+ 41.Kxf3 d1=Q+
A.1.b) 40.Kf2 d1=N+
A.1.b.1) 41.Kf1 Ne3+ 42.Kf2 Ng4+
A.1.b.2) 41.Kg1 Qe1+ 42.Kh2 Qh1#
A.1.c) 40.Kf1 d1=Q+
A.2) 37.Qe3 Bg4+
A.2.a) 38.Kf4/Ke4 Qe5#
A.2.b) 38.Kg2 d2! 39.Qxc3 d1=Q (threatens 40...Bh3+! 41.Kxh3 Qh1#) 40.f3/f4 Qe2+ 41.Kg1 (41.Kh1 Qf1+ 42.Kh2 Qf2+ 43.Kh1 Bh3 and black must toss the queen before getting mated) 41...Bh3 and mate shortly. B) 36.Ke3 d2+ transposes into A.1.
C) 36.Nc4 d2+
C.1) 37.Ne3 d1=Q+
C.2) 37.Ke2 Bg4+ 38.f3 Bxf3+
D) 36.Na4 Qc2 37.Qe4+ g6 38.Nc5 dxc5 39.bxc5 Qe2+ 40.Qxe2 dxe2 41.Kxe2 Bd7 Now to post this and see what happened. |
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| Jan-21-11 | | Patriot: Wow...I started out correctly but didn't think 35...Bg4+ was best. I'll have to look at this later. |
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| Jan-21-11 | | Pygeum Lycopene: Came close, but... black's third move was my second. does 35...Qc3 still win for black or has the win vanished in the blink of a patzer's eye. |
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| Jan-21-11 | | Patriot: I made a number of mistakes.
(A.2.a) - completely wrong...it's not mate.
(A.2.b) - 38...d2? 39.Qxc3 d1=Q and I missed 40.Qf6. There are more errors in this line. (D) isn't exactly perfect but still winning. |
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Jan-21-11
 | | gawain: Oh, my!
I saw the start but could not imagine the extremely elegant finish. |
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| Jan-21-11 | | k.khalil: Me too, I saw the start, but couldn't calculate all the way, |
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| Jan-21-11 | | wals: Another one to add to my impressive list of failures. Totally overlooked if 34...Bh3+ 35.Kxh3 QxQf4
36.gxf4, then d3 could safely promote to Queen.
Rybka 4 x 64
White error: d 16 : 8 min :
(=-0.53):32.Qe8+. Best,
1. = (-0.11): 32.f4 Be2 33.Kf2 Qe7 34.Qh1[] f6 35.Nc4 Kf8 36.Ne3 Qe8 37.Nc4 f5 38.Ne3 g6 39.c4 Qa4 40.Qb1 Qa3 41.b5 Qxa5 42.bxa6 Qd2 43.Qe1 Qxe1+ 44.Kxe1[] bxa6 45.Nd1 Kf7 46.Nc3 a5 47.Kd2 White blunder: d 22 : 5 min :
(-12.91):34.Qf4. Best,
1.  (-0.77): 34.Qe1 g5 35.f3 gxh4 36.gxh4[] d2 37.Qxd2 Qxh4[] 38.Qe3 Qh3+ 39.Kf2 Qh2+ 40.Ke1 Kg6 41.Qf2 Qf4 42.Ke2 h4 43.Qe3 Qh2+ 44.Qf2 Qe5+ 45.Qe3 Qg3 46.Qf2 Qf4 47.Qe3 Qh2+ 48.Qf2 Qe5+ 49.Qe3 35.Kf3, -13.94 increased the deficit,
was really nothing better.
Black blunder: d 16 : 3 min :
(-4.60):35...Bg4. Qxc3 -13.94 was best.
White blunder, 37.Qe4, -15.03,
virtually ended the game for White,
who indeed resigned after move 39. |
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| Jan-21-11 | | frenchfan: The game continuation was quite nice, but personally I would have preferred to crush my opponent slowly with 35...Qe7. |
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| Jan-21-11 | | thegoodanarchist: In the words of Borat: "Veru nahs" |
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