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|Dec-09-07|| ||goodevans: Seems to me that black needed to leave his bishop on f8. Has anyone posted a refutation to 26 Nxf7 Rxf7 28 Rxc5 Qxc5 yet? If they have then I must have overlooked it. Strikes me that 29 Bb3 Nd8 30 Qg6 looks good for white but I can't see all the way through to a clear win.|
|Dec-09-07|| ||xrt999: wow I got the first 2 moves, but went with 28.Bb3, pinning the rook on f7. In fact, white did not move his LSB the rest of the game.|
Black responds with 28...Nd8, defending the f7 square and opening up queen defense of g6. White cant play Qg6 now, which was move 28 in the actual game.
ironically, 28.Qg6 is a decent move, but is met with 28...Rxf5 by CM.
28...Kf8 just loses
|Dec-09-07|| ||znprdx: I think the Nxh6+ approach is more direct like <willyfly:>'s line. Then everything is possible...Like <dzechiel:> OTB I'd more likely have opted for Rxc5[N]. Deciding the move order is the challenge, but it seems White just wins regardless - (who knows maybe even Nxg7) As for the text I thought the threat was Bb3...never considered Qg6 since 27...Qxc5[R] seemed preferable.|
Well maybe not: 26. Nxf7 Rxf7[N] 27.Rxc5[N] Qxc5[R] 28.Bb3 Nd8 29. Bxh6 gxh6[B] 30.Qg6+ Kh8 forced 31.Bxf7[R] Nxf7[B] 32. Qxf7[N] Qc6 OK the odds were clearly in white’s favor. Now 33. g4 with a rook lift would win but 33. h3! and there is no defence to Ra7.
Now the only question is how come it is so difficult to create (force) these type of opportunities in the real world and then to maintain one’s sanity while grinding out the win, given that at any moment it could all be for naught.... the slightest little resourceful counter sac or transposition. But <dumbgai> put it best:<I guess this is why these players are GMs/IMs while I'm only a....??? :-)
|Dec-09-07|| ||TrueBlue: put me in the Rxc5 team ... I believe it does give advantage, but the position is way too complicated ... Maybe only computers can help here ...|
So I did saw some of the ideas in the game, but how do you decide the order of the moves !?!??!?
|Dec-09-07|| ||johnlspouge: Sunday puzzle (Insane)
Material even, for White a distinct advantage in space, particularly on the King's side, suggesting mating possibilities. White also has a distinct advantage in piece coordination, with some pressure on Nc5 and Nc6, which Ba4 pins to the Re8. The pressure creates the potential for overburdening the Bf8 protecting Pg7, and more immediately Rc7 protecting Pf7. The only tender point in the White position is Pd3 and the lack of luft for the King. Black has the immediate threat h6xNg5, which is provoking Nxf7. All of this suggests queen-side action will overburden pieces defending the King side.
26. Nxf7, Nxh6, Rxc5.
The candidates 26. Nxf7 and Nxh6 appear not to work, because the Black pieces (especially with the Bf8) can repel a direct attack on the King. Without the Bf8, we have 26. Nxh6 gxh 27. Qxh6 and things generally look promising. Let's try overburdening:
Without exact calculation (I have a life), 26...Bxc5 27. Nxh6 now appears to open the Black King up completely and gives excellent compensation for what is essentially an exchange sacrifice, after White picks up Ps for the N.
Thus, Black recaptures 26...Qxc5 or captures 26...hxg6. The move 26...hxg6 just permits Rac1, which looks crippling for Black.
26...Qxc5 27. Rc1 [Qa7 28. Bxb4 and the Bf8 disappears] Qb6
so White can bring about the diagram position without the Nc5 and Ra1. This now suggests that the pinned Nc6 is the key and that it is the K-side action that is subordinate to increasing pressure on the Nc6. Now,
28. Nxf7 Rxf7 29. Qg6 looks awfully good for White.
There is a lot of calculation required to ensure that the ideas work, but the themes seem all there. It is time to peek.
|Dec-09-07|| ||zenpharaohs: All I can see in this is that it isn't that big a deal between|
and for sure, the game line is not the solution, because 32 ... Kxe7?? gave the game away instead of 32 ... Rxe7.
|Dec-09-07|| ||Jimfromprovidence: Can someone please run iterations on the following line? I think it holds a lot of promise for white but it gets rather complicated.|
26 Rxc5 Bxc5 27 Nxg7 Kxg7 28 Nxf7 Rxf7 29 Bxh6+ Kf6
|Dec-09-07|| ||Jimfromprovidence: <goodevans> <Seems to me that black needed to leave his bishop on f8. Has anyone posted a refutation to 26 Nxf7 Rxf7 28 Rxc5 Qxc5 yet? If they have then I must have overlooked it. Strikes me that 29 Bb3 Nd8 30 Qg6 looks good for white but I can't see all the way through to a clear win.>|
28… Qxc5 is worse for black because it loses material right away. If 29 Qg6 black probably has to play 29… Rxf5 to stop 30 Nxh6 and a strong mate threat (because the king has no real escape squares). After 29… Rxf5 30 exf5 and white is up a knight for a pawn.
|Dec-09-07|| ||fm avari viraf: White has an attacking position & Black's Achilles is f7. But how to exploit it? The first thing that comes to mind is 26.Nxf7 Rxf7 27.Rxc5 removing the menacing Knight ...Bxc5 28.Qg6! [ not 28.Bb3 then ...Nd8 & Black will survive ] Now, White threatens 29.Nxh6+ hence ...Kf8. But still the position looks more complex & requires more thought & analysis. The sweet memories of the Asian Games 1978 come to my mind vividly as I played many Blitz games with Vasuikov & people used to be confused as who was the real Russian GM as both of us had similar appearance.|
|Dec-09-07|| ||MostlyAverageJoe: <Jimfromprovidence: Can someone please run iterations on the following line? ... 26 Rxc5 Bxc5 27 Nxg7 Kxg7 28 Nxf7 Rxf7 29 Bxh6+ Kf6>|
It has been done already. See my response to <dzechiel>. Here's the direct link: Vasiukov vs Y Rantanen, 1988
White should win easily, but the line is predicated on the 26 ... Bxc5? inaccuracy (very tempting for the black, though).
|Dec-09-07|| ||dzechiel: <MostlyAverageJoe: <dzechiel: <sigh> Not even close.>|
Actually, you were closer than you think.>
Thanks for the follow up, Joe. While I'm usually one of the first to post, I typically check back several times to see additional comments and analysis. Your comments are never less than interesting.
|Dec-09-07|| ||zb2cr: I do not believe it! The first Sunday puzzle I have EVER gotten! Some 25 minutes of thought required; I also cheated. I wrote down analyzed lines as I completed them. |
Okay, here's where I impersonate <dzechiel> and give my thoughts of the analysis.
Material's even. Black's c6 Knight is pinned. This constricts Black's Queen, but there seems to be no way to attack her. Black's Rook at e8 is loose. What is striking is the concentration of force by White on the Kingside, especially h6. Black has his Bishop at f8 indirectly protecting the h6 Pawn. The Knight on g5 masks the black-squared Bishop. We need to get it out of the way.
26. Ne6, Rxe6 is no good, it just brings the Rook to the defense of the Black h6 Pawn, and unpins the Black Knight to make the defense ... Nd8 available.
26. Nxf7. Black should recapture, as White is threatening 27. N7xh6+ with a discovered attack on the loose Rook. The alternative 26. ... Ra8; 27. N5xh6+, gxh6; 28. Qg6+, Bg7; 29. Nxh6+, Kf8; 30. Qd6+ looks very promising for White.
So back to the more natural line for Black, 26. ... Rxf7. Okay, now we try to decoy the Black Bishop out with 27. Rxc5. What happens if the Black Bishop doesn't decoy and Black captures with the Queen? Then, White plays 28. Rc1 and Black's Queen is driven back to b6, and White follows up with 29. Qg6! threatening the fork 30. Nxh6+. Black can't move the Rook off of f7 because his Rook at e8 is loose! So if Black captures with the Queen, he's in a world of hurt--so he should play 27. Bxc5 and we've achieved our decoying.
28. Qg6 works here, and Black has to play 28. ... Kf8. 29. Bxh6! and if 29. ... gxh6; 30. Qxh6+, Kg8; 31. Bb3, Bf8 (to prevent Qg7#--the pinned Rook can't retake); 32. Qg6+, Kh8; 33. Qxf7 with the threat of 34. Qg8#.
So Black can't take after 29. Bxh6! and will probably play 29. ... Ree7--finally solving the problem of his loose Rook. But then White can play 30. Qh7, threatening a back-rank mate. Black has to run away with 30. ... Ke8. White plays 31. Qg8+.
Here's where I diverged from the game. I figured Black to play 31. ... Rf8; 32. Nxg7+, Rxg7; 33. Qxg7. White has three Pawns for his sacrificed Knight and is threatening a 4th.
|Dec-09-07|| ||zenpharaohs: In the game line,
28 ... Kf8
is not the only continuation for black.
28 ... Ree7
and black is maybe a little better off.
As far as the puzzle, I put it to Shredder 11 and Rybka 2.3.2a and they both like 26 Rxc5 better than 26 Nxf7 so far at 18 plies deep. It is a very small difference though. So I am not sure that we can all just pass by 26 Rxc5. There is no rabbit in that hat either though.
|Dec-09-07|| ||DukeAlba: I agree with <MostlyAverageJoe> that 26. Rxc5 is the better move. The only reason that white wins as a result of Nxf7 is because black handles the situation horribly.|
I disagree with the continuation in the game..... it looks weak with too many oppurtunities for black to defend....
|Dec-09-07|| ||DukeAlba: I'm on the <<<<<26. Rxc5 Team>>>>>|
|Dec-09-07|| ||DukeAlba: Can anyone run an analysis or post a response to 28....Ne7 as a response for black? In my opinion it would have destroyed white's attack....|
I just disagree greatly with black's choice of 28....Kf8..
I think, as I said earlier, that Rxc5 threatens black more forcibly than does Nxf7.
|Dec-09-07|| ||resty: my choice was 26.Rxc5|
|Dec-10-07|| ||MostlyAverageJoe: < DukeAlba: Can anyone run an analysis or post a response to 28....Ne7 as a response for black? In my opinion it would have destroyed white's attack>|
Uh, nope, it leads to an immediate loss. All black moves below (after Ne7) are forced:
28. ... Ne7?? 29. Nxh6+ Kh8 30. Nxf7+ Kg8 31. Nh6+ Kh8 32. Qxe8+ Kh7 33. Nf7
click for larger view
and at this point I plugged the position into Hiarcs which claims forced mate in 8 moves.
|Dec-10-07|| ||MostlyAverageJoe: <DukeAlba: I agree with <MostlyAverageJoe> that 26. Rxc5 is the better move. >|
I only wrote that 26. Rxc5 is a very good move. With best defense, it is NOT as good as the line played in the game (which might be optimal for both sides until the 32...Kxe7 blunder.
26. Rxc5, however, is quite likely to elicit the inaccurate response 26...Bxc5 rather than the correct hxg5 (although openingspecialist was not fooled by it, and one should not assume that the opponent will fall for a trap).
The best time to play Rxc5 was one move earlier, as 25.Rxc5 (discussion of <openingspecialist>'s suggestion of starting the puzzle one move earlier is where I made the comment that it would be better than the line played in the game).
<openingspecialist: <MAJ> that line transposes anyway doesnt it?> Only if black plays inaccurate 26...Bxc5.
|Dec-10-07|| ||DukeAlba: Oh.... Ok. Wow that was bad. I guess your right. Thanks.|
|Dec-10-07|| ||kevin86: The brilliant twin sacrifices set this one up! A good one!|
|Dec-10-07|| ||patzer2: For yesterday's extremely difficult Sunday puzzle, White plays the demolition of pawn structure combination 26. Nxf7!! Playing over this complex variation with the help of a computer might prove helpful.|
|Dec-10-07|| ||alphee: Insane? May be. I saw the 26.♘xf7 ♖xf7 sequence with some possible following moves but ♖xc5 looked as a mandatory step to eliminate the ♔night and possibly allow ♗c3 at a latter satge. In fact I could not link the two and went to the solution from wich I was very far.
I wonder how many people did find the full sequence.|
|Dec-10-07|| ||zb2cr: alphee>,
I may have come the closest to the game continuation. Many posters opted for 26. Rxc5, which may transpose to the actual game. At least 4 others saw the basic ideas of the initial 2 moves, but were unable to find the correct follow-up.
Since this is the very first Sunday puzzle I have ever solved, I'm inclined to attribute it to dumb luck on my part.
|Dec-11-07|| ||alphee: <zb2cr> thanks for the posting. Luck is something very strange. Gary Player, a famous South African golfer, used to say "the more I train the luckyiest I become". I expect you accumulated a lot of training and this site is one of the best place for it ... in my view at least.|
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