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Later Kibitzing > |
| Jul-18-08 |
| officeplayer: Now after 20.h5, 20. ... Nxd5(which transposes into the position i gave in my previous post) was compulsory to keep the initiative. Instead, black threw it all in White's hands with 20. ... f5?, which creates an illusion about central pressure, but in fact, weakens black king side tremendously. And now black is forced to accept the bishop sac 21.g4! e4, which lead to this position in the game:
click for larger view
which evaluates about +1.30 and is won for white. |
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Jul-18-08
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| whiteshark: Oh, <officeplayer>, I see we worked/posted simultaneously on the same line. :D |
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Jul-18-08
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| 4tmac: I kind of like 33. N-e5+ even though it takes an extra move since it gets all the pieces "in the game". |
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Jul-18-08
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| johnlspouge: Friday (Difficult): White to play and win.
Material: Down a B. White has a battery Rh1 and Rh3 on the h-file, and strong pressure against the Kf8 with Nc6 and Qe6 occupying advanced outposts. Black has a threat of mate-in-one with Qxb2#, so if White is to counterattack, it must be with continued check until the mate threat is lifted (in today's case, by mate :) Candidates (29.): Rh8+
29.Rh8+
Tedious calculation demonstrates mate. Black has 2 legal moves. (1) 29…Bxh8 30.Rxh8+ Ng8 [Kg7 31.Qh6#] 31.Qh6+
The Kf8 can flee, or Rf7 can interpose:
(1.1) 31…Ke8 32.Rxg8+ Kd7 [Rf8 33.Qxf8+Kd7 Rg7#]
33.Qe6+ Kc7 34.Qxf7#
(1.2) 31…Rg7 32.Qxd6+
The Rg7 can interpose, or Kf7 can flee to 1 of 2 squares: (1.2.1) 32…Re7 33.Qxe7#
(1.2.2) 32…Kf7 33.Qe6+ Kf8 34.Rxg8+ Rxg8 33.Qe7#
(1.2.3) 32…Ke8 33.Rxg8+ Rxg8 [Kf7 33.Qe6#] 34.Qe7#
(2) 29…Ng8 30.Qxd6+ Ke8 [Re7 31.Qxe7#]
31.Rxg8+ Bf8 [Rf8 32.Qe7#]
32.Rxf8+ Rxf8 33.Qe7#
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Jul-18-08
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| johnlspouge: <<Gilmoy> wrote: <29.Rh8+ Bxh8 30.Rxh8+ Ng8 31.Qd6+> Kg7 oops. We must first force Black to self-blockade g7.> Yes. Calculation is mostly important for showing what does <not> work. I went through this variation before calculating the happy consequences of 31.Qh6+. |
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Jul-18-08
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| PinnedPiece: Playing through the game, I guessed 29 Rh8+ ok, and the followup, but had a difficult time on move 33 Qe6+, which seems to me to be almost as clever as the rook sac. 33 ? is as difficult for me...I think probably harder than yesterday's anyway...... |
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| Jul-18-08 |
| Samagonka: This one fits well into my pattern of thinking: I got the first 3 moves without trouble and the rest doesn't seem to be too complicated either. Good Friday for me. |
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Jul-18-08
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| Marmot PFL: This is not terribly difficult, given the game situation. White is a piece down and threatened with mate on b2. The only chance is to get to black first - Rh8+ Bxh8 (Ng8 Qxd6+) Rxh8+ Ng8 (Kg7 Qh6#) Qh6+ (not Qxd6+ Kg7) Rg7 Qxd6+ Kf7 (Ke8 Rxg8+)here is where my calculation ended, but black has no escape and the rest is not hard Qe6+ Kf8 Rxf8+ Rxf8 Qe7mate. |
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Jul-18-08
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| Marmot PFL: <officeplayer> The rating gap in this game was oven 500 points, so Bologan takes some chances (0-0-0) he probably would not take against another 2700 player. |
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Jul-18-08
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| JG27Pyth: Not at all hard to guess the initial rook sac... but there really are a lot of variations to look into (I had to set this up on the board to convince myself I saw all that needed seeing) but every variation leads to mate I believe. Here's a sideline I don't think has been mentioned:
29.Rh8+ Bxh8 30.Rxh8+ Ng8 31.Qh6+ (the king tries running:) Ke8 32.Rxg8+ Kd7 (and now 33.Rxb8 is obviously winning for white but better yet is mate in two...) 33.Qd6+ Kc7 34.Qxf7# |
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| Jul-18-08 |
| zb2cr: I didn't see the game line to completion. Instead, I tried 33. Ne5+, Ke8; 34. Rxg8+, Rxg8; 35. Qd7+, Kf8; 36. Qf7#.
One move longer, but using some of the same ideas. |
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| Jul-18-08 |
| DarthStapler: I saw the first 3 moves in one of the variations I analyzed but not Qxd6+ |
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Jul-18-08
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| johnlspouge: <<JG27Pyth> wrote: [snip] Here's a sideline I don't think has been mentioned: > Your variation is (1.1) in my post, with your <33.Qd6+> correctly written as <33.Qe6+>. C'mon, <JG27Pyth>, you mean to say you didn't read <all> my variations? ;>) I nearly fell asleep myself today. |
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Jul-18-08
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| Bishoprick: As problems go, sort of icky. You know that every move has to be a check or Black mates. In each case, there is only one (or two checks) available. So. . . |
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Jul-18-08
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| YouRang: Ach! I saw the whole thing up tp 33.Qe6+ Kf8, but then my board vision failed me, and I didn't see the lovely finale: 34.Rxg8! |
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Jul-18-08
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| kevin86: I have an alternate move that IMHO works better. Oops,correction 31  d6+ but black parries with  g7
The fullexchange would leave white a rook down:(
Maybe I ought to get a job in the banking industry. |
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| Jul-18-08 |
| ruzon: I did not see that 31.Qxd6+ is met by Kg7 either, but the banking industry isn't the place to be right now. Go do some engineering or art, kevin86. Creating is good for the soul. |
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| Jul-18-08 |
| MiCrooks: I agree with the other poster...the fact that you are facing mate in one makes this problem easier than it otherwise might be. You know that every move has to be a check. So even if you didn't see immediately where things were going, you would immediately reach for Rh8+ as your key move. Then it is just a matter of sorting through alternatives to find the right path. This is the kind of game that I really like to back up a few moves and see how they got themselve into this sort of razors edge position, where whoever has the move wins. |
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| Jul-18-08 |
| MiCrooks: Whiteshark: in your first diagram, yes Black is a pawn up but White has plently of compensation. In these positions the initiative outweighs material, and computers are notoriously bad about figuring this out. For instance, after h5 what would be Black's reply? The computer settles on Re8 which is reasonable threatening e4, but White has hxg6 and Black must recapture as he cannot allow gxf7. Which way to recapture? Say hxg6 then after Rh4 White's position has a lot of potential and Black's attack appears to be going nowhere. I'm not saying Black is lost by any means, but I think White would have been fine playing into this line. By playing into this position he was saying that he was willing to gambit this pawn for the initiative. |
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| Jul-18-08 |
| AccDrag: Oh, interesting blindspot by me... I do all my analysis without a board, so sometimes I hallucinate badly with retained images. :-D |
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Jul-18-08
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| Kasputin: Black is up a piece and threatens an immediate mate on b2. For that reason nothing works with the white knight as a first move because the knight cannot deliver check. A defensive candidate move would be 29. Qe2 but this is not all that satisfying for fairly obvious reasons (same with moving the king). Candidates:
a) 29. Rh8+
b) 29. moving the queen - Qxf7+, Qxe7+, Qc8+
a1)
29. Rh8+ Bxh8
30. Rxh8+ Ng8 (if ...Kg7 then 31. Qh6#)
31. Qh6+ Ke8
32. Rxg8+ Kd7
( or ...Rf8 33. Qxf8+ and then 34. Rg7#)
33. Qe6+ Kc7
34. Qxf7#
a11)
29. Rh8+ Bxh8
30. Rxh8+ Ng8 (if ...Kg7 then 31. Qh6#)
31. Qh6+ Rg7
32. Qxd6+ Kf7 (or 32 ...Ke8; 33. Rxg8+ Rxg8; 34. Qe7# - and of course 32 ...Re7 leads to 33. Qxe7#)
33. Qe6+ Kf8
34. Rxg8+ Rxg8
35. Qe7#
a2)
29. Rh8+ Ng8
30. Qxd6+ Ke8 (...Re7 then 31. Qxe7#)
31. Rxg8+ Rf8
32. Qe7#
a21)
29. Rh8+ Ng8
30. Qxd6+ Ke8 (...Re7 then 31. Qxe7#)
31. Rxg8+ Bf8
32. Qe6+ Re7
33. Qxe7#
And since 29. Rh8+ looks like it works in all variations, there is no need to think about any queen moves as candidates. That is, if I didn't miss anything. |
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Jul-18-08
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| Kasputin: Well I think I got this. Some other time, I will go back and see if all of this is correct. If there is an error, please point this out fellow kibitzers. Despite the necessity of white to continue with check after check, doing this puzzle is about the limit of my board vision right now. |
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Jul-18-08
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| JG27Pyth: <C'mon, <JG27Pyth>, you mean to say you didn't read <all> my variations? ;>)> JohnLSpouge... when you've got to use the Dewey decimal system to catalog your variations it's time to step away ;) (FYI -- I think I like the 1.1.1 1.2.1 etc. labels... is that your innovation? I don't think I've seen it before.) |
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Jul-18-08
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| zenpharaohs: I think I got this (another "second man through" play), but since I was reinstalling the operating system on the computer I didn't do any computer checking yet. |
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Jul-19-08
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| patzer2: For the Friday, July 18, 2008 puzzle solution, Bologon initiates a mating attack with 29. Rh8+! See either <johnlspouge> or <Kasputin>'s posts for detailed analysis. |
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Later Kibitzing > |
sac: 23.gxf5
