< Earlier Kibitzing · PAGE 2 OF 4 ·
|Oct-28-09|| ||WhenHarryMetSally: it's unbelievable that only two pawns are lost for the whole game!|
|Oct-28-09|| ||costachess: Shams: <Graham Clayton> I'm not so sure, I think 39.a4 intending a4-a5-a6 rips open a queenside file. |
--- No , don't rips a queenside!!
|Oct-28-09|| ||Nostrils: Rf6 looks the most interesting move. It allows a dynamic possibilty of the white knight attacking the queenside pawns at the expense of the black rook taking over the kingside.
37 .. Rf6
38 Ne7 Rf4
white must contemplate if Ne7 - Nc8 is too expensive.
37 .. Rf6
38 h5 Rxf5
38 exf5 Nf6
and black picks up the h pawn.
|Oct-28-09|| ||AnalyzeThis: That's interesting, Nostrils. You're saying that you don't play 37....Rxf5, you play 37.... Rf6, meeting 38. h5 with Rxf5 at that point. |
But, once you play ...Nxh5 like you're planning, can white sac a pawn with f6 to provide way in?
|Oct-28-09|| ||JG27Pyth: Once you determine that Black is playing for draw the Rxf5 exchange sac seems pretty simple... but I strongly doubt I'd have ever thought of it OTB because the position looks so drawish to me in the first place -- I'd never have realized the fortress building tactic was necessary. Very nice play from Larsen to get the win from there.|
|Oct-28-09|| ||agb2002: Material is even. White threatens 38.gxf7. Black can alleviate his cramped position with 37... Rxf5 38.exf5 Nf6 forcing a complete blockade: if White eventually plays b6 then ... a6 seals the queen side and similarly, if White plays a6, then ... b6 achieves the same goal. To any other White's move, Black only needs to move his king.|
Any other plan might allow the maneuver Ne7-Nc8 forcing a6 or a5 with the subsequent weakening of Black's queen side and the invasion of the white rook.
|Oct-28-09|| ||gofer: I think the point of the puzzle is to notice some or all of the following;|
a) the black king is hemmed in and is open to back rank mate issues if white's rook can get through anywhere.
b) The white king is going to come to f3 to protect both e4 and g4, so that the black night can't move out of the defensive position it is in.
c) Once the white king is on f3 the rook will be completely free to move.
d) If black plays h5 then the rook is free to take the loose pawn.
e) If black doesn't play h5 then the white king can infiltrate along the c8 - h3 diagonal.
f) If the black rook chooses to move to c7 then the white rook can control the f file.
g) If the black rook doesn't move from the f file then white can eventually swap off rooks and black knight
can move to e7 and c8 at which point the black king is trapped unless the black knight moves and if
it moves the d6 pawn is lost.
So I see no good opportunities for black, I only see good opportunities for white.
So I think black should play for a draw.
37 ... Rxf5
38 exf5 Nf6
This is a draw. There is no way through black's defences for the rook or king, unless white sacs the rook.
Time to check...
|Oct-28-09|| ||patzer2: Black's missed opportunity 37...Rxf5!, building a defensive fortress as suggested by <Graham Clayton> and <RV>, is the solution to today's Wednesday puzzle.|
|Oct-28-09|| ||bengalcat47: Since this week's theme is draws I have to state that one of the most intriguing I've ever seen is Halprin vs Pillsbury, 1900 In particular the play of the game speaks well for Pillsbury's exceptional skills.|
|Oct-28-09|| ||patzer2: Also interesting in this game is Larsen's surprising exchange sac and passed pawn combination with 46. Rxg4!! .|
|Oct-28-09|| ||cocker: This is a position that defeats a Silicon Monster. Mine thinks that White is winning after 37 ... Rxf5, but cannot achieve the win.|
|Oct-28-09|| ||Eisenheim: Right away when I saw this position, I thought of the game where Nakamura beat Rybka and tied up the board. 37 Rxf5 will enable that to occur. And then black can choose a time and way to strike at his convenience or merely draw the game (which seems to be the theme). Important lesson to remember here is not to blindly cling to material's relative worth. A rook is only worth more than a knight, if the situation dictates a rook is needed. In a fortress a knight will generally prevail since it can leap where the rook is bound by the structure of the board.|
|Oct-28-09|| ||Nostrils: <AnalyzeThis: But, once you play ...Nxh5 like you're planning, can white sac a pawn with f6 to provide way in?>
Good point to watch out for.
37 .. Rf6
38 h5 Rxf5
39 exf5 Nf6
40 Kg2 Nxh5
41 f6 Nxf6
The squares e4,f4,g4 and g5 are all controlled by black, so there is no route through for the white king. I don't see any rook sacrifices that would work, so it looks ok.
|Oct-28-09|| ||euripides: <al wazir I think the losing move was 39...h5> I was going to agree and say how difficult passive defence is: but I think Black is in zugzwang. |
The very nice idea of a fortress after <39...Nf6 40. Nxh6+ gxh6 41. Rxf6 Kg7 42. Re6 h5> seems not to work after 43.a5 Kf8 44.Kf2 (zugzwang again) Kg7 (or Rd8 45.g7+ Kf7 46.g8+ to break the blockade) 45.Re8 Kxg6 46.Ra8 e.g. 46...b6 47.axb6 axb6 48.Rb8. If 43...a6/b6 White exchanges pawns and the rook cannot protect the weaklings on the 6th rank. But I could be wrong.
Other moves look unpromising for Black. 39...Nf6 40.Nxh6+ Kh8 41.Nf7+ Kg8 42.Ng5: 39...Kh8 40.Nxd6 threatening Rf8 mate: 39...Rd8 40.Ne7+ Kh8 41.Rf8 mate: 39...Rc7 40.b6 opening lines. Perhaps Black can try 39...Nc7 40.b6 axb6 41.Rb1 Na8 but I guess White can penetrate even then.
|Oct-28-09|| ||zb2cr: Phooey. My second miss of the week. I saw the first move, but had no real idea how to proceed from there. Not my week, it appears.|
|Oct-28-09|| ||carelessfills: 37...Rxf5. After that, Black just sits. It's obvious that White has no entry point or pawn levers on the Kingside since Black has full control over f6. Black doesn't even need to play Nf6 ever, as long as it remains on d8! Black can also choose to play h5 or let White play it first!!|
White's only try for a pawn lever is on the queenside, but Black should do nothing there until forced to. Black just sits on the queenside, waiting for White to commit. White's Rook, on its own can not do anything without a pawn lever to open up a file. If White plays b6, Black answers with a6. If White plays a4 and a5, Black still sits and waits and does nothing against the seemingly imposing white pawn front, since Black can counter either of White's final advances of a6 (or b6) by advancing his own pawn to b3 (or a6) completely blocking the queenside.
This last setup of two adjacent pawns on the Black's 2nd rank against two opposing White pawns on the 5th rank is a common defensive maneuver to slow down White's kingside attack in many Schevenigen like variations in the Sicilian defense, where White gets pawns at g5 and h5, and Black still doesn't waste time defending until White advances one to the 6th rank and instead pursues his own action on the queenside or centre.
|Oct-28-09|| ||lost in space: <Black only needs to move his king.>|
If white got to a5 and b5, Black has to avoid to move Kc7 as then White can play b6+ and at least one file is open. This might not be enough but why to take a risk?
|Oct-28-09|| ||carelessfills: White can even helpmate himself if he tries to hard on the Kingside!|
37 .... Rxf5
38 exf5 Kg8
39 Kg2 Kf8
40 Kg3 Ke7
41 Kg4 Kd7
42 Kh5 Nf6#
|Oct-28-09|| ||lost in space: I think the moves 25. b5 and 37. g6 were mistakes.|
|Oct-28-09|| ||TheaN: Wednesday 28 October 2009
Bogey (+1s <> +1m)
Candidates: <[Rxf6]>.............yeah :)
Knowing the theme of the week, it's easy to KNOW Black would like to draw; however, the position calls for it as well. The weak d-pawn and the attack on the Rook lead to a terrible position for Black after 37....Rf6 38.Nd7 where Black is completely paralyzed. So, what's the swindle?
<37....Rxf6!!> and for once giving away a stronger piece for a weaker one will actually strengthen one's position. The point is that White's Knight is definitely the strongest piece otb, and Black also has the attack on the Rook to par. With the keymove he does both, but does it draw?
<38.exf6 Nf6 39.a4 Kg8 40.a5 Kf8 41.b6 (41.a6 b6 =) a6=> and White can make no progress. If the White King approaches, he can't progress past the fourth rank, both the pawns and the Knight block all squares. If White ever tries a breakthrough with the Rook, Black shouldn't capture to preserve the draw, although no single breakthrough actually seems to win. Time to check.
|Oct-28-09|| ||TheaN: 2/3
Ah, make that 37....Rxf5 38.exf5. Furthermore, I think I kind of underestimated the strength of Rd7 as a defensive move; but still, if Black wanted to draw he should have considered Rxf6. I guess he didn't.
|Oct-28-09|| ||randomsac: giant pawn chain. nice|
|Oct-28-09|| ||Mate Hunter: <Nostrils> idea of playing 37...Rf6 instead of 37...Rxf5 certainly looks interesting.|
Could anyone perhaps make a deeper analysis of the position and possibilities after 37...Rf6?
|Oct-28-09|| ||johnlspouge: Wednesday (Medium/Easy)
Larsen vs E Torre, 1987 (37...?)
Black to play and win.
Material: Even. The White Kg1 has 5 legal moves. Black is disadvantaged by lack of space, but the position is closed, so he can make a fortress.
Candidates (37...): Rxf5
37…Rxf5 38.exf5 [else, drop a N]
To open the position, White must sacrifice R for Pe5. (Black can lock a- and b-Ps, so the Q-side provides no invasion point. Under no circumstances can the R safely reach the a-file to attack Pa7.) With best play, the game is a clear draw.
|Oct-28-09|| ||njchess: Ouch! I got this one but either Torre was trying too hard for a win, or he was in time trouble.|
< Earlier Kibitzing · PAGE 2 OF 4 ·