| Nov-08-14 | | Cheapo by the Dozen: Material is dead even. The most obvious shot is Rxg7, either immediately or after a clearance by the d4 knight, but I don't see much in the way of follow-up. The next most obvious is probably Nxe6, and that is much harder to defend against, as in: 24 Nxe6 fxe6
25 Nf4 Kf7 (the only way to defend e6)
26 Rxg7+ (thus ... Kf7 didn't actually work)
That said, the line I'm suggesting is a pretty direct path to getting rook and 2 pawns for 2 knights, which is not exactly a proven and resounding win. Still, it suffices to make the line look like something worth trying over the board, especially since White is likely to have the option of declining the recapture of the exchange and taking the g7 pawn instead. |
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| Nov-08-14 | | Cheapo by the Dozen: I'm having trouble even coming up with a halfway active defense for black after 24 Nxe6+ fxe6
25 Nf4
The threat is Nxe6+, forking king, queen, rook and g7. And in lines where White plays Rxg7, he's apt to follow soon with Qxh6. Black can try the passive
24 Nxe6+ fxe6
25 Nf4 (Q moves)
26 Nxe6+ Ke8
but after
27 Nxd8 (Black recaptures)
28 Rxg7
White already has a material advantage that he's likely to extend. And I'm guessing that 27 Rxg7 is even better for White. |
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| Nov-08-14 | | Cheapo by the Dozen: OK. I somehow thought the Black queen was unprotected, the d7 rook notwithstanding. Still, queen, some pawns and an attack is a good return for a rook and 2 knights, so I'll claim a considerable degree of success on this Saturday puzzle. ;) |
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| Nov-08-14 | | diagonalley: diagonalley: nul points |
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| Nov-08-14 | | diagonalley: although CG is a good web-site, the tracking of live games has been far too slow... so i shall be following sochi elsewhere |
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| Nov-08-14 | | plumbst: Very Difficult. Material is even.
Black's pieces are cramped and his Queen and King are vulnerable to a possible fork, therefore 24.Nxe6+! fxe6 (forced, of course)
25.Nf4 Kf7.
Not much choice here either, otherwise Nxe6+ destroys the kingside 26.Rxg7+! Kxg7 (26...Ke8 27.Nxe6 is devastation)
27.Nxe6+ Kh7
28.Nxc7 Rxc7
and now maybe
29.Qf4 looks bad for Black. Not sure if there's something better though. |
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| Nov-08-14 | | plumbst: 27.Qg3+! was a nice move by Castaneda; the line leads to a much simpler win than 27.Nxe6+. |
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Nov-08-14
 | | Richard Taylor: I found the first few moves but I was considering 25. Nf4 Qh5 then I thought 26. Rd5 was the move. It is but I was thinking of Nxd5 27. Qf3 when I was trying to organise a mate on g6 or Rg9+ and Ng7# but I also thought of 27. Nxg7+ which at least picks up 3 pawns for the piece but in fact it seems to lead to a forced mate or an easy win. <plumbst> Yes. I only considered Ne6+ but thought that the main problem was 27. ... Qh5 Interesting. Even if I couldn't see all the lines I would have gone for 24 Nxe6+ I wouldn't be able to resist it...win or lose! But Castenada played it beautifully for sure. |
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| Nov-08-14 | | gofer: The target is obvious; Pe6. Lets start by getting rid of one defender and re-load the knight... <24 Nxe6+ fxe6>
<25 Nf4 ...>
Now are blunt attack is very very obvious, but still difficult to defend against... Okay, I have looked at king moves and they don't seem great. I am a little concerned
about Qa5, but haven't got enough time today wade through the variations... ~~~
Hmmm, only half a point today. I didn't think Ke7 was playable, I thought it was better
to save the queen immediately and try to bring it from a5 to h5. <What do our silicon friends say?> |
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| Nov-08-14 | | GrandMaesterPycelle: Easy enough to see the idea, although the many intermediate moves by white eluded me. |
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| Nov-08-14 | | agb2002: The material is identical.
The relative position of Black's major pieces and the lack of a good defender of the light squares around the king invites to play 24.Nxe6+ fxe6 25.Nf4: A) 25... Kf7 26.Rxg7+
A.1) 26... Kxg7 27.Qg3+
A.1.a) 27... Kf7 28.Qg6+ Kf8 29.Nxe6#.
A.1.b) 27... Kf8 28.Qg6 and mate soon.
A.1.c) 27... Kh7 28.Qg6+ Kh8 29.Nxe6 Bf8 (29... Rg8 30.Qxh6#) 30.Bxf6+ followed by Nxc7 is disastrous for Black. A.1.d) 27... Kh8 28.Qg6
A.1.d.i) 28... Rg8 29.Qxh7#.
A.1.d.ii) 28... e5 (to close the a1-h8 diagonal) 29.Ne6 Rg8 (29... Bf8 30.Nxc7 Rxc7 31.Qxf6+ + - [Q+2P vs R+N]) 30.Qxh6+ Nh7 31.Nxc7 Rxc7 32.f4 and White has the queen and three pawns for a rook and two knights and keeps some attack. A.1.d.iii) 28... Ne5 29.Qxh6+ Nh7 (29... Kg8 30.Nxe6 Bf8 31.Qg5+ Rg7 32.Qxf6 Qe7 33.Bxe5 seems to win decisive material) and White's attack sems to lose steam. A.1.e) 27... Kh8 28.Nxe6 Rg8 29.Qf4 with the double threat 30.Qxh6+ and 30.Nxc7 is similar to A.1.d. A.2) 26... Ke8 27.Qxh6, menacing 28.Qg6+ Kf8 29.Qf7#, looks winning (27... Ra8 28.Nxe6 threatening Qg6#, Qh8+ and Nxc7+). A.3) 26... Kf8 27.Nxe6+ Ke8 27.Qxh6 as in A.2.
B) 25... Kg7 26.Rxg7+ as in A (26... Kh8 27.Qxh7+ Nh7 28.Qxh7#). C) 25... Qa5 26.Nxe6+ followed by Nxg7 (probably much better than Nxd8) with three pawns for the knight (the h-pawn is hanging) and a strong attack. |
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Nov-08-14
 | | scormus: <plumbst: 27.Qg3+! was a nice move by Castaneda; the line leads to a much simpler win than 27.Nxe6+.> Yes, I thought this little finesse was the neatest part of the sequence. Finding 24 Nxe6 was not much of a challenge - one of the classic piece sacs against the Sicilian - nor the next 2 moves (a lot easier than yesterday). But the one after was cool |
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| Nov-08-14 | | morfishine: White pressures <e6> & <g7>, the latter thru the former via the Knights (besides the direct pressure from the Rook), so this becomes largely a matter of move-order. With that said, I felt best was to start with 24.Nxe6+ I had <24.Nxe6+> 24...fxe6 25.Nf4 and here I thought Black defends best with 25...Qa5; and here it seems the "branches" sprout in all directions, one improvement after the other for each side that I became dizzy and simply left it at that. For example, after 26.Nxe6+ Kf7 27.Nxg7 Rh8 28.Nf5 Bf8 we get this:
click for larger view***** |
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| Nov-08-14 | | kevin86: White sacrifices..and then winds up material ahead! Sounds odd, doesn't it? |
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| Nov-08-14 | | Strongest Force: Maybe white is a descendant of the famous psychic/peyote-guru? :) |
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Nov-08-14
 | | Jimfromprovidence: White can answer 25...Qa5 (instead of 25...Kf7) with 26 Bc3.
click for larger view There only are two choices here, 26...Kf7 (which loses the queen) or 26...Nb4. If 26...Nb4, then 27 Ne6+ looks good. 
click for larger viewAfter 27...Kf7 28 Rd5!? deserves a close look. (The knight cannot recapture because of Rg7+ Ke8 Qxh6, etc ). 
click for larger view |
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Nov-08-14
 | | Penguincw: Like most people, I found the obviously 24.Nxe6+ fxe6. I was going to followup with 25.Bxf6, but 25...Bxf6, and black's position remains solid. |
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| Nov-08-14 | | morfishine: <Jimfromprovidence> Yes, I looked at <28.Rd5> in your line (and in others placing the rook on <d5>), but thought Black could confuse things with 28...b5, but it doesn't matter much after 29.Rxg7+ Ke8
30.Qxh6
Hard one to visualize
***** |
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| Nov-08-14 | | Bobsterman3000: Overall this is an example of what can happen when you're too passive and don't mount any offense - your opponent has a free hand and time to build up a huge sacrifice-based attack of their own. |
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| Nov-08-14 | | M.Hassan: "Very Difficult"
White to play 24.?
Equal
I beleive I started the right line but can not get results!24.Nxe6+ fxe6
25.Rg6 Kf7
26.Qg3 Nh4
27.Rxg7+ Nxg7
28.Qxg7+ Ke8
29.Nf4 Bf8
30.Qg8 Rf7
31.Qg6 Be7
32.Nxe6 Qc8
33.Qxh6
Stalled.
White has gained a Knight+4 pawns and Black a Kinght and a Rook.
Do not see where I have gone wrong. have to check. |
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| Nov-08-14 | | TheBish: G Castaneda vs Jobava, 1998 White to play (24.?) "Very Difficult", material is even. Black has a typical defensive Sicilian position, almost a hedgehog setup. White has more space and aggressively posted pieces, almost perfectively placed. But where is Black's weakness? It's very hard to spot, but actually, e6 is weak! "What's that?" you say. "It's defended by the f7 pawn, the best defender there is!" Well, that may be true... but after that's gone, how do you defend it? That's the reasoning I used to come up with an amazing sacrifice. 24. Nxe6+!! fxe6 25. Nf4!
Now it becomes a little clearer. The threat is nothing less that winning the queen with a knight fork, and the only way to defend the weakened e6 square is 25...Kf7. A move like 25...Qa5 does nothing to diminish White's attack, as after 26. Nxe6+ Kf7 27. Rxg7+! Kxe6 28. f4 d5 29. exd5+ Kd6 30. dxc6+ and White cleans up nicely. 25...Kf7 26. Rxg7+ Kxg7
click for larger viewNow the natural 27. Nxe6+ Kg6 28. Nxc7 Rxc7 29. Qg3+ Kf7 30. Qf4 Ne5 31. Qxh6 should be good enough to win, but there is even better... 27. Qg3+! Kh8 28. Nxe6 Rg8 29. Qf4 Rg6 30. Nxc7 Rxc7 31. c5! Kh7 32. cxd6 Rd7 33. e5 Ne8 34. Qf5 Rd8 35. Rd3 Ng7 36. Qe4 
click for larger viewand White has too many threats (36... Bg5 37. h4 Bxh4 38. Qxh4) and has an overwhelming position. The moral of the story is: If you are going to play the Sicilian Scheveningen variation as Black, you should keep the light-squared bishop to defend e6! Short of that, your pieces need to be coordinated enough so that they have mobility and are not boxed out of the defense -- as here, where the Rd7 blocked the queen from defending e6. |
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| Nov-10-14 | | patzer2: For the Saturday Nov 8, 2014 puzzle, White begins with a demolition followed by a devastating quiet move, threatening a royal Knight fork after <24. Nxe6+!! fxe6 25. Nf4!> In the game, Black chooses to allow the Knight fork after <...25 Kf7 26. Rxg7+> If 26...Qa5 (the most practical alternative to allowing the fork), then 27. Bc3! Nb4 28. Nxe6+ Kf7 (diagram below) 
click for larger viewand White has many winning options. The most clever win here is 28. Rd5! pointed out by <Jimfrom providence> (see last diagram in Jim's post), when play might continue 28...Nfxd5 29. Rxg7+ Kxe6 30. exd5+ Kf5 31. Qf3#. Also here (my diagram above) White has the more straight forward 28. Rxg7+! Kxe6 (28...Ke8 29. Qxh6  ) 29. h4! when play might continue 29...Qh5 30. Qh3+ Qg4 31. Rxg4 . <...25 Kf7> Black sees nothing better than offering up the Queen for Knight and Rook. <26. Rxg7+ Kxg7>. Here Black likely expected 27. Nxe6+ , which wins with a bit more difficulty than White's next surprise move. If 26...Ke8, then 27. Qg3! threatening 28. Qg6+ is crushing. <27. Qg3!> Not essential, but stronger than 27. Nxe6+ Kg6 28. Nxc7 . <27...Kh8 28. Nxe6+ Rg8 29. Qf4!> Threatening a decisive double attack with 30. Qxh6# or 30. Nxc7 winning the Queen. <29...Rg6 30. Nxc7> and with decisive material the rest is a mop up operation as in the game continuation. |
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| Apr-08-17 | | Eduardo Bermudez: I like chess, played logic and dynamics, like this game! |
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Kibitzing
+ sac: 24.Nxe6+