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|Dec-22-07|| ||Chesstalesfan: Thanks Alshatranji. Let us think what is coming then: 16Qh7+ Kf7 17Bxe5 threatening the pawn g7 and the file f is open for the white
If 17..Rg8 18.Rf3
if 17..Bf6 18 Bxf6 and now neither the black K nor the Q is recommendable to take the white bishop on f6. I thought also that may be black ignores the pawn g7 and plays 17..Ke8 Afterwards:18Bxg7 with complications , to me favorable for the white. Black can team up his pieces upon defending and it seems to me that even he succeed through exchanges, the three dreadful pawns f2 g2 h2 ,as a compensation for a light piece, decide the endgame. Still we have not involved the knight d2 in the battle..
|Dec-22-07|| ||DarthStapler: Greek gift etc.|
|Dec-22-07|| ||Eggman: After 14...f6 15.Rh3 the move 15...fxe5 opens up the f-file and gives the e5 square to White's Knight. Therefore after 16.Qh7+ Kf7 I think that the key move is 17.Nf3, giving the position below.|
click for larger view
17...exf4 18.Ne5+ Kf6 19.Rh5 Bd6 (19...g5 20.Ng4#) 20.Qg6+ Ke7 21.Nxc6+, etc.
17...Bf6 18.Nxe5+ Bxe5 19.Bxe5 Rg8 20.Rf3+ Ke7 22.Bf6+, etc.
17...Nd7 18.Nxe5+ Nxe5 19.Bxe5 Bf6 20.Bxf6 Qxf6 21.Rf3 Qxf3 22.gxf3, etc. This line is perhaps tennable for Black.
17...Ke8 18.Qg6+ Kd7 19.Nxe5+, etc.
|Dec-22-07|| ||patzer2: For today's difficult Saturday puzzle solution, White plays the demolition of pawn structure combination 12. Bxh7+!! In essence, it's a positional pseudo sacrifice which creates complications that win quickly or equalize with difficulty. It's not a true sacrifice, because with an equalizing option in hand White isn't taking any real risk of losing. It's early enough in the opening this could be a prepared variation, where GM Campora knew his opponent could equalize only if he could find 14...f6!|
|Dec-22-07|| ||patzer2: <eggman> After <14...f6! 15.Rh3 fxe5 16. Qh7+ Kf6 17. Nf3 exf4 18.Ne5+ Kf6 19.Rh5>, Black's OK after 19...Qe8= (not <19...Bd6??> 20. Qg6+ Ke7 21. Qxg7+ Ke8 22. Qg6+ Ke7 23. Rh7+ Rf7 24. Qxf7#). Do you have a winning continuation after 19...Qe8 = here? Until someone can prove otherwise, I'm assessing 14...f6!= as fully equal.|
|Dec-22-07|| ||zev22407: To Al Wazir if 19)..N-e4 20)Nxe4 fxe4
21)R-g4 threatening R-f4+
|Dec-22-07|| ||Alphastar: <patzer2: Until someone can prove otherwise, I'm assessing 14...f6!= as fully equal.>|
I thought so too. I got stuck on 14. ..f6 and I think I would've gone for the perpetual then.
|Dec-22-07|| ||Chesstalesfan: Gentlemen, patzer2 and eggman, tell me please why we have to abandon the 17Bxe5|
|Dec-22-07|| ||patzer2: <Chesstalesfan> I was wondering when someone would suggest 14...f6! 15.Rh3 fxe5 16. Qh7+ Kf6 <17. Bxe5>, which may be White's best chance to press for an advantage here. I'm currently running a long analysis on it with Fritz 8, and will post my results later.|
P.S. 17. Nf3 seems to secure the draw and gives Black more problems to solve, and as such might be preferable.
|Dec-22-07|| ||patzer2: It would appear White can press for advantage after 14... f6! 15. Rh3 fxe5 16. Qh7+ Kf7 17. Bxe5! Ke8 18. Bxg7 Rf5 19. Qg6+ Kd7 20. Rh8 Qc7 21. Bd4 Bd7 (or 21. b5 ). (0.97 @ 14 depth, Fritz 8). |
In addition to 14...f6!, Black can also play 15...Ne4! 16. Qg6 Qd7! 17. Nxe4 fxe4 to make a fight of it.
|Dec-22-07|| ||zooter: can somebody explain the set of moves (in the game) to me pls?|
22.Ng6 (I guess the idea would be Nh8+??) Qd7 23. c3 (Whoa!!! protecting the b-pawn???) Rb7 (Why?)
|Dec-22-07|| ||MaczynskiPratten: I'm with alWazir on Nxe4. Obviously dxe4 is bad and fxe4 is better. The attraction is that it swaps a useless Black knight which eventually just gets in the way for White's Knight which eventually presses home the attack. I didn't believe Nb7. Again, would be very interesting to see computer analysis on these lines.|
|Dec-22-07|| ||znprdx: CG puzzle began at 12. White to move.....at 15 ply i.e. 19.White to move plays b4...which suggests the attack had come to a grinding halt - |
it was instructive in the sense that White demonstrated tremendous patience and self-control - OTB I'd more likely continuing blasting away until I was fighting for a draw in lost endgame :)
the following dance of the knights was cute ...hardly forced ... but at 29 ply White leaves the decoy knight (the g6 target) en prise ...as the the final zugswang leads to mate ...a pretty painting as each brush stoke squeezes the life out of Black.
|Dec-22-07|| ||sanyas: They shouldn't be allowed to give us puzzles like this. I spent ages looking for a <solution>, such was my naivete.|
|Dec-22-07|| ||patzer2: Here's a look with Fritz 8 (move-by-move @ 15 depth):|
<12. Bxh7+ !! Kxh7> White's demolition is a safe positional sacrifice, assuring him a quick victory or a favorable position.
<3. Qh5+ Kg8 14. Re3 f5>
Putting up more resistance is 14... f6!? 15. Rh3 fxe5 16.
Qh7+ Kf7 17. Bxe5 Ke8 18. Bxg7 Rf5 19. Qg6+ Kd7 20. Rh8 Qc7 21. Bd4 .
<15. Rh3 Qe8>
Black can improve his survival chances with 15... Ne4!? 16. Qg6! Qd7! 17. Nxe4 fxe4 18. Rh7 Bg5! 19. Bxg5 Qf7 20. Qxf7+ Rxf7 21. Rh3 .
<16. Qh7+ Kf7 17. Rg3 Rg8 18. Bh6 Bf8 19. b4 Nb7 20. Nf3 Nd8 21. Nh4>
Winning quicker is 21. Rg6! Ba6 22. Rf6+ Ke7 23. Qxg8 gxf6 24. exf6+ Kd7 25. Ne5+ Kc7 26. Bxf8 .
<21... Rb8 22. Ng6 Qd7 23. c3 Rb7>
This loses quickly. Black puts up more resistance with 23... c5 24. Nh4 Ke8 25. Qxg8 gxh6 26. Ng6 Qg7 27. Nxf8 Qxg8 28. Rxg8 Kf7 .
<24. Bg5 a6 25. Nh4 Be7 26. Bh6 1-0>
Black resigns in the face of the threat 26...Bf8 27. Qg6+ Ke7 28. Bg5#.
|Dec-22-07|| ||johnlspouge: Saturday (Very Difficult) White to move and win.
Material even. Spatial advantage on the K-side and most of Black's pieces are elsewhere. The Q and 2B's are ready to rake Black's K-side, and the Re1 supports Pe5 and is ready for a lift. There is an immediate threat of minor exchange against Bd3. The Black Nc5 is supported once and many of its moves are neutralized by the Nd2. The stab b4 might be useful in some lines to disrupt Black's defenses.
Candidate moves: Bxh7+ (otherwise White's advantage dissipates)
Other later candidates are Re3, Qh5, Bh6. (From my Thursday crash and burn, I have learned to keep looking at all your candidates, not just your top choice.)
12.Bxh7+ Kxh7 [otherwise Qh5] 13.Qh5+ Kg8 14.Re3 ( h3 h8#)
so if the Pg7 moves the White Q controls the Black K's exit. This is a dream attack, and the final candidate Bh6 (this week's theme!) starts to look important. Thus,
14...f6 or f5 15.Rh3
16...Qe8 16.Qh7+ Kf7 17.Rg3 Rg8 18.Bh6 Qf8 or Bf8 toasts Black
It does not appear that 16...something else makes a lot of difference. Time to peek.
It will be interesting to see how critical b4 was to plug the K's exit.
I see why CG warns that they do not make the puzzles easier each week. At least I learned from my crash and burn on Thursday. Time to look at the kibitzing. I am sure everyone is congratulating themselves over 12.Bxh7+.
|Dec-22-07|| ||UdayanOwen: Okay, unless I spend three days on this I won't be able to generate an algorithm to demonstrate that 12.Bxh7 wins (if there is one.......)|
But anyway, 12.Bxh7 is the only move, that generates forcing play, so it has to be the solution.
So there you go.
|Dec-22-07|| ||UdayanOwen: Actually, I was planning to analyze a little more deeply than that....
so give me an hour or more, and I will put something up.|
|Dec-22-07|| ||kevin86: The first few moves of this one is easy-it is just the details of the follow up moves that make the puzzle hard.|
The theme this week is very instructive-sometimes is can be quite profitable to sacrifice a minor piece or two to open the adverse king position.
|Dec-22-07|| ||TrueBlue: I thought it was very easy. I am sure something like this works:|
12. Bxh7+ Kxh7 13. Qh5+ Kg8
14. Re3 g6 15. Qh6 Bh4 16. Rh3 g5 17. Nf3 gxf4 18. Nxh4 Re8 19. Nf5 Qf6 20.
Qxf6 exf5 21. Qh8#
|Dec-22-07|| ||johnlspouge: <UdayanOwen: I was planning to analyze a little more deeply than that...>
Analysis is not necessary to play 12.Bxh7+. On positional grounds alone, it "obviously" is the right move . I just wrote the post to practice my analysis routine and to internalize* it.|
*This is to let you know that you are not the only one familiar with psychobabble :)
|Dec-22-07|| ||zb2cr: Okay, what Vladimir Vukovic calls the "classic Bishop sacrifice" is on order at h7. I was able to see the first 6 moves, for White and Black, but after I reached the position after Black's 18th, didn't see any way of carrying on. At that range, even with all forced moves, my board vision gets very cloudy. |
I'm going to give myself 1/2 credit.
Oh, and for those wondering why Black resigned after move 26. White is threatening 27. Rxg7+. Black can't allow this. If he does nothing to protect g7, then 27. Rxg7+ forces 27. ... Rg7 (27. ... Kf8??; 28.Rxg8# or 27. ... Ke8; 28. Rxg8+, Bf8; 29. Rxf8#). Then White plays 28. Qxg7+, Ke8; 29. Qg8+, Bf8; 30. Qxf8#.
Returning to Black's 26th move, his only way to protect g7 is to play 26. ... Bf8. But this opens him up to 27. Qg6+, Ke7 (forced); 28. Bg5#.
|Dec-22-07|| ||Jimfromprovidence: I think black can escape with 15...Qc7?!
|Dec-22-07|| ||patzer2: Notice how 21. Rg6! would have decisively exploited the pin on g7 (my post above) to prepare to deflect the King and win the unprotected Rook.|
|Dec-22-07|| ||UdayanOwen: 12.Bxh7+ Kxh7 13.Qh5+ Kg8 14.Re3 (14.Nf3 f6 leads nowhere).|
White's principal threat is Re3-h3 and mating on the h-file. Black will have to move the f-pawn on this move or the next to avoid this. This means he can play either 14...f6 or f5 now, or play one of many other moves first. Essentially, whichever move order happens will transpose to the other, so let's we'll give him two options now:
Against both of these f-pawn moves, the only other plausible candidates 15...Rg3 or Bh6 don't seem to hold up under analysis.
What I did next, rather than calculating what will happen after any number of possible black moves, was to first analyse what white is threatening, and only THEN work out what black moves will deal with that....
I don't have time to explain properly, but I came to the conclusion that there are pretty much no moves for black in either line that prevent the forcing, material recovering variations that are threatened by white (and several moves actually make things worse in my concrete analyses, including any piece to d7 (this square is needed later for the king) 15...Qe8 (blocking the king's escape route to d7) and 15...Re8 (16.Qh7+ Kf7 [16...Kf8 17.Rg3 ] 17.Bh6 Bf8 18.Rg3 )
So my chosen move is 15...Rb8, since when the smoke clears in the best forcing variations I can find for white, black is still in the game and this move, activating the rook and hitting the b-pawn, is the most useful.
14...f5 15.Rh3 Rb8 16.Qh7+ 16...Kf7 17.Bh6. Playing against g7 in this way is the only plan that I can find that leads to winning chances after 12.Bxh7. White will win g7 (and if my analysis is correct, an exchange), because attempts to hold it lose:
17...Rg8 18.Rg3 Bf8 (18...Qf8 19.Qg6#) 19.Qg6 Ke7 20.Bg5
Basically then, black's plan is to escape to d7 with a minimum of damage and hopefully with enough material to win or draw.
I've looked at lots of possibilities, but I'm not going to write an exhaustive analysis of the subtle variations... white seems to get the g7 pawn and win the rook for bishop one way or another no matter what black does, leaving white with two pawns and a rook for the two bishops, with the passed h-pawn as a positional reward.
Here are some sample lines, after 17.Bh6:
17...Ke8 18.Bxg7 Kd7 (18...Rf7?? 19.Qg6, when 20.Rh8 will give white a winning material advantage no matter what black does). I can't see anything better than 19.Bf8... black's king is safe, and white hopes that his passed h-pawn and extra rook will be superior to the two bishops.... and they may well be, because the black pawn structure will not be conducive to the bishop's activity.
17...Rg8 18.Rg3, and no matter what black does on this move, he will have to give up his rook the next after 19.Bxg7 Rxg7 (since he can't allow a winning discovered check). Again, black will be able to escape to d7, and the same strategical analysis about the rook and h-pawn versus two bishops applies.
I can't find anything better for white....
This analysis is continued in my next post, where I analyze the 14...f6 line...
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