< Earlier Kibitzing · PAGE 1 OF 3 ·
|Feb-10-11|| ||Fish55: 61. a6, bxa6 62. Kc6 forces the pawn through.|
|Feb-10-11|| ||belgradegambit: Very easy for a Thursday.|
|Feb-10-11|| ||dzechiel: White to move (61?). Material even. "Medium."
In a blitz game, I play
with the idea of 62 d7+ and 63 Kxb7 followed up with the a-pawn promotion. But I don't think that works here, as black can play
and the white king cannot go to a7 without forfeiting the a-pawn to the knight.
So, the first move must be with something other than the king. Moving the bishop doesn't make progress...
Aha! That's it!
with the threat of 62 a7 and 63 a8=Q+.
Black has little choice here. Trying to intercept the pawn with 61...Kb8 allows 62 d7+ and 63 d8=Q.
Staying on the white squares ensures that the knight won't deliver any unwanted checks.
Black is toast here. If he doesn't take immediate action, white is going to follow up with 63 d7+ Kd8 64 Bh4#.
Attacking the bishop, the pawn, and covering h4. But, alas, it's too late...
63 d7+ Kd8 64 Bc7+ Ke7 65 d8=Q+
There may be some other lines, but I think you get the idea.
Time to check and see how this one went down.
|Feb-10-11|| ||Phony Benoni: OK, I got off on the wrong track on this one. Whenever +wrong colored rook pawn appear, I start looking for ways to push the pawn through anyhow. Here, I was considering 61.Kb6, 62.d7+ and 63.Kxb7. But Black replies 61...Nd5+ and 62...Nf6, and can always cover d7 with his knight.|
So instead of sacrificing the d-pawn to get the a-pawn through, the process needed to be reversed.
There's a fascinating ending in the database--might be a Louis Paulsen game--that shows a subtle way of winning with the wrong colored rook pawn. I thought of looking for it, but now it seems irrelevant.
There will likely be a number of winning tries in analysis today. We'll see if any others pass msuter.
|Feb-10-11|| ||rilkefan: I'm thinking a6 then bxa6 is forced, and then Kc6 wins. On the other hand knight endgames are too hard for me. On the other other hand, I read a little of Nunn's Understanding Chess Endgames over the holidays and this problem seems very easy.|
|Feb-10-11|| ||al wazir: I can boast that I did as well as a GM on this one.|
|Feb-10-11|| ||NM JRousselle: Black had the better of it in this ending. If he had played 45... Nd2, White may have trouble saving the game.|
|Feb-10-11|| ||estrick: For several minutes I couldn't see anything better than 61 Kc5. I was about to give up and look at the game continuation, when . . . |
I finally realized that if the King could get to a square such as c6, it would be immune from knight checks (at least temporarily) and would be able to guide his pawn to d7 with check, followed up by the bishop seizing control of the queening square, and even threatening mate. So, deflecting Black's b pawn away from control of c6 by sacrificing his a pawn allows White to carry out that plan. If Black does not accept the proffered pawn, then the a pawn threatens to queen, and Black will not be able to stop both pawns.
If this had been OTB, I probably would've played Kc5. Hopefully, I'll know better in the future now that I've done this puzzle.
|Feb-10-11|| ||scormus: After overlooking the neat #ing tactic yesterday I felt I must try better today. I hadnt quite rubbed the sleep out of my eyes but 61 a6 looked decisive enough. Then if B played anything other than ... bxa6+ then either the a- or d-pawn Qs (or even # on d8). So I got quite a shock when I saw 61 Kc5 .... then that little "A" which gave me hope. And yes, 61 a6!|
|Feb-10-11|| ||consul: <NM JRousselle: Black had the better of it in this ending. If he had played 45... Nd2, White may have trouble saving the game.>
Why? In that case as White i would play Bd8 winning a pawn... Black can get a strong pawn group on the east wing, but i don't see a big problem: after all White will still have a Bishop, long runner.|
|Feb-10-11|| ||Jimfromprovidence: White must not have seen a win after 61 a6 Bxa6+ 62 Kc6 Nf5.|
click for larger view
But as <dzechiel> noted, the win is there after 63 d7+ Kd8 (only move) 64 Bc7+!
click for larger view
Its a bit of a tricky puzzle but not too much so. Its interesting to look at why 63 Kc5 does not work (basically that move throws away the winning tempo).
|Feb-10-11|| ||TheBish: C Sandipan vs F Slingerland, 2008|
White to play (61.?) "Medium"
At first, I thought the object was to trade the d-pawn for the b-pawn, and then queen the a-pawn, but that doesn't seem to be possible: 61. Kb6 (preparing d7+) Nc4+ and the fork forces the king back, 62. Kb5. Then I saw a way to queen the d-pawn instead!
The key is to give away the a-pawn, in order to queen the d-pawn.
Otherwise the a-pawn will queen, or if 62...Kb8 63. d7+ queens the d-pawn.
63. Kc6! Nf5 64. d7+ Kd8 65. Bc7+ Ke7 66. d8=Q+ and the rest is easy.
|Feb-10-11|| ||think: Got this one, but I missed yesterday's. And a bunch of people said yesterday's puzzle was easy...|
|Feb-10-11|| ||rilkefan: <White must not have seen a win after 61 a6 Bxa6+ 62 Kc6 Nf5>|
I don't think one could not see this - of course the pawn wants to be pushed and the bishop wants to control the queening square. I would guess rather that white just wasn't thinking of mate or sacrificial solutions in an endgame.
|Feb-10-11|| ||Eyal: Yeah, I was thinking something similar about <White must not have seen a win after 61 a6 Bxa6+ 62 Kc6 Nf5. But as <dzechiel> noted, the win is there after 63 d7+ Kd8 (only move) 64 Bc7+!>. This is just a matter for speculation, of course, but I doubt if that's the reason 61.a6 wasn't played - it seems to me that once you spot the basic idea of diverting the black pawn, so that the king can enter c6, the question of whether the bishop hits the d8 queening square from h4 or c7 is secondary and easy to solve. The whole a6 idea was probably missed for some other reason - among other things, nobody told Sandipan at the crucial moment that it's a puzzle and White has a winning combination...|
|Feb-10-11|| ||Dr. J: <think: Got this one, but I missed yesterday's. And a bunch of people said yesterday's puzzle was easy... >|
That's easy to explain: If you solve the puzzle, it was easy; if you don't, it was hard.
|Feb-10-11|| ||TheaN: Thursday 10 February 2011
Material: White, +2 vs +2 endgame
Candidates: d6, Kb7, <[a6]>
These kind of endgame position are trivial, yet again also each case on its own. One single tempo, one single threat can thwart a completely won position to a hopelessly losing one.
Characteristics of this position are the wrong bishop for the a-pawn meaning that if we remove the white d-pawn it is pretty much drawn on the spot. This should make obvious d6 is certainly not the move. A bishop move makes no real progress, aside from Bh2 blocking the pawn. However, that is instantly hampered by the fact white's time is not a plenty and Nf5 makes winning one hell of a job. Kb7 is the only reasonable alternative to the keymove, but this prones the white king for twentysixthousand forks of which Nc4 should be most clear being drawn. Alas we followup with, taking note that the queen-rook pawn is considerably useless in the bishop endgame:
<61.a6> purely to make access to c6. Ironically, the a-pawn himself is so threatening now black has no choice but to give up the c6 square.
<61....axb6> acting dynamically with 61....h4 is too late on account of 62.a7 with 63.a8=Q , a knight move just as much; from where is he supposed to guard a7 or a8 anyways: 61....Nf5 62.a7 Nxd6 63.Kb4 , always diagonally two squares away and the tempos are gone. The move 61....b6 is similar to the keymove, as in that it just allows Kc6 with the a-pawn still on the board.
<62.Kc6> typically, 63.d7 with 64.Bc7 or Bh4 is unavoidable. 62....Nf5 63.d7 Kd8 64.Bc7 Ke7 65.d8=Q . Perhaps best is moving away at this move:
<62....Kd8 63.Bh4 Ke8 64.d7 Kf7 65.d8=Q > and this is no check, the knight is shut now anyways. Time to check.
|Feb-10-11|| ||gmalino: an endgame with a lot of possibilities...
and black gives the Knight for the last white pawn-draw....
But this could be a winning position, couldn't it?
is even worse for white....
Ah, no, I overlooked some important detail in the first line.
and now blacks King can't stop a8Q!
But Black can try harder!
61.Kb6 should be answered by
62.Kb5 N anywhere
63.B forcing Knight to flee
64.Kb6 should work!
Checking. (took me 20 min.)
|Feb-10-11|| ||agb2002: White has a bishop dor a knight.
Black might consider maneuvers like Nf5-Nd4-Nf3 controlling h4 and h2 to force White to trade the bishop for the h-pawn.
On the one hand, the knight cannot control the promotion squares a8 and d8, directly or indirectly (with a fork involving the white king). On the other hand, the white bishop controls the dark squares and it would be useful to control some light squares, namely c6 and d7 to support the d-pawn. Hence, 61.a6:
A) 61... bxa6+ 62.Kc6
A.1) 62... Nf5(g2) 63.d7+ Kd8 64.Bc7+ Ke7 65.d8=Q+ wins.
A.2) 62... Nd5 63.d7+ Kd8 64.Bh4+ Ne7 65.Kd6 a5 66.Bxe7#.
B) 61... Kb8 62.d7+ and 63.d8=Q wins.
C) 61... b6 62.a7 (or 62.Kc6, similar to A) Kb7 63.d7 + -.
D) 61... <other> 62.a7 + -.
|Feb-10-11|| ||sevenseaman: With the basic idea to avoid putting my K on a dark square so I deny Black N a check with tempo, I go|
61. a6 Black needs to 61...bxa6 (if not then a7 and Q)and I go 62. Kc6 ~ 63. d7+ and the game belongs to me with Bc7+ check in hand.
When I saw the solution I was disappointed as I saw Sandipan draw.
I have checked all possibilities and still have a win.
Then I see some kibitzing and find support for my line from <eyal> who refers to <dzechiel> somewhere down the page. Shall see.
I am new to the daily puzzle. I hope its ok or a draw would be the only right solution?
|Feb-10-11|| ||mike1: ok, yes , got a6...
The main question is : where did Black go wrong (in the endgame)?
I think 58... Nd2 is the one.
I think Black could play 58.. Kd7! instead. 59 Kxb7 Nxa5+ is a draw, no doubt. Black just plays h4 and if Bxh4
then Nxa5 and Kd6 with Kxd5 to follow.
|Feb-10-11|| ||LoveThatJoker: White wins with 61. a6! The main idea is that if 61...ba, then play continues with 62. Kc6 Nf5 63. d7+ Kd8 64. Bc7+ and 65 d8=Q+ winning.|
It should also be noted that if Black refuses the pawn then White will win by moving the a-pawn and queening one of his passers.
Of course if Black plays 61...Kb8 then there will be no need to move the a-pawn as 62. d7+ will win outright.
|Feb-10-11|| ||gofer: I think this one is all about turning the knight into useless lump of wood. At the moment he is aint good but he aint useless either.
He is helping black to control a6 and d7 because Nf5 is going to make things difficult for white. So white needs
to get his king to c6 then white can play 1 d7+ Kd8 2 Bc7+ Ke7/Ke8 3 d8=Q+ winning. So there seems to be only one
way to get the king to c6...
<61 a6 ...>
61 ... Nf5/Nd5/Kd7 62 a7 and Pa7 will promote
61 ... Kb8 62 d7+ Ka7 63 d8=Q winning
61 ... b6 62 a7 Kb7 63 d7 and either Pa7 or Pd7 will promote
<61 ... bxa6>
<62 Kc6 ...>
click for larger view
Black cannot stop Pd6 because its knight has turned into a "useless lump". It cannot attack the king
except by taking two moves and it cannot get to the bishop or protect d7.
62 ... Nf5 64 d7+ Kd8 65 Bc7+ winning
62 ... Nc2 64 d7+ Kd8 65 Bc7+ winning
62 ... Nc4 64 d7+ Kd8 65 Bc7+ winning
One nice continuation is...
<62 ... Nd6!?>
<63 d7+ Kd8>
<64 Bh4+ Ne7>
<65 Kd6! a5>
Time to check...
|Feb-10-11|| ||Willber G: <al wazir: I can boast that I did as well as a GM on this one.>|
Ha ha, me too!
|Feb-10-11|| ||knight knight: 61. a6 is the first move I see, if 61...b6 62. a7 Kb7 63. d7 wins, if 61...h4 62. a7 and queens, 61...Kd7/d8 62. a7 and 61...Kb8 62. d7+|
There are eight knight moves after 61. a6. The knight somehow has to get to b6 or c7, but the d6 pawn protects c7 and the king b6. If 61...Nd5 62. a7 Nc3+ 63. Kc4! b5+ 64. Kxc3 Kb7 65. d7. So white plays 62. a7 and wins.
This leaves 61...bxa6 62. Kc6 with the threat 63. d7+, which looks winning:
a) 62... Kb8 63. d7+
b) 62...Kd8 63. Bh4+
c) 62...Nd5 63. d7+ Kd8 64. Bh4+ Ne7 65. Bxe7+ Kxe7 66. Kc7
d) 62...Nf5 63. d7+ Kd8 64. Bc7+
Ok time to check...
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