< Earlier Kibitzing · PAGE 2 OF 3 ·
|Dec-03-10|| ||goodevans: <Sastre>
My apologies. I was looking at the position after <24 Nd6> rather than <25 Nd6>.
|Dec-03-10|| ||Zozeke: Once I glimpsed on this position, I immediately wanted to take the hanging Knight. But back-rank mate was looming around, so I jumped on 24. Rc3 and Black Queen really has no move to keep the threat alive, hence Knight termination becomes legitimate. I gave up looking any further, though it was pretty obvious to me that puzzle labeled 'Difficult' may contain a life-saving trick for Black.|
But... There is nothing Black could do to compensate that Knight's loss? Nope? Really? Sigh, by thinking: 'CG tricks me' I tricked myself.
|Dec-03-10|| ||David2009: Y Xu vs A Ushenina, 2006 White 24?|
Black is a Pawn up and is threatening mate in three starting 24...Qc2+ which gets White's attention. So 24. Rc3 and now:
(A) Black can play to win with 24...Qa4!? but 25 Bxg7 Bxg7 26 Nf6+ Nxf6 27 Qxa4 Rxc3 28 gxc3 Nd4 29 Rc1 does not give Black enough
for his Queen sacrifice: White simply returns the exchange and grinds out a win on material
(B) 24...Qa6 relaxes the pressure on b6 and allows 25 Bxg7 since if Bxg7 26 Rg3 mates. Instead 25...Kh7 Rg3 and White is clearly winning.
Time to check the game:
Not very good analysis. 24...Qa6? gives away the Nd7 which I had not noticed was en prise. As yesterday, I missed Black's best defence. The regulars have analysed with more skill: respect!
Crafty End Game Trainer link to the puzzle position:
click for larger view
Y Xu vs A Ushenina, 2006 White 24?
Crafty EGT captures the Rook on move 25: 25...Qxd7 26.Bxg7 Bxg7 27.Nf6+ Kh8 28.Nxd7 Bxc3 29.bxc3 Rc7 to reach
click for larger view
This position should be won for White but the EGT will defend stoutly. Over to you to finish the game if you want to, using the link above.
|Dec-03-10|| ||Once: CG.com continues to ring the changes. Today's puzzle starts not with a smiting move, but with a defensive move. With 24. Rc3, white stops all of black's mating threats and has time to continue with his attack.|
The role of the Nd7 is interesting. After 24. Rc3 Qb5, we get to here:
click for larger view
The Nd7 is on defensive duties. Now it is very difficult (not impossible, just very difficult) to knight fork an enemy knight. This means that knights make good defenders against knight forks. And the Nd7 is doing just that - keeping an eye on f6 to prevent white's Ne4 from landing there.
But there's a problem with knights defending against knights forks ... they have to stand very still to maintain the defence. A queen, bishop or rook might be able to slide up or down a file or diagonal and still keep contact with a square or attacked piece. But a knight has to stand still.
Defensive knights are also vulnerable to being exchanged. The Nd7 guards f6 by being a knight move away from that square. But if the knight is exchanged for a more valuable piece, not only is the defence gone but we now have another piece in forking range of an enemy knight.
And that is what happens here. When white plays 25. Rxd7, black dare not recapture with his queen. He is either going to get mated or lose his queen to a knight fork.
I guess the moral is this - yes, you can use a knight to defend against a knight fork. Just be very careful that your opponent can't make you swap that knight for something more valuable to be dragged into forking range,
|Dec-03-10|| ||YCP: Why not Bxg7, threating Bf6 with quick mate? If he takes then Rg3|
|Dec-03-10|| ||Sastre: White can't play 24.Bxg7 because of 24...Qc2+ 25.Ka1 Qc1+ 26.Rxc1 Rxc1#.|
|Dec-03-10|| ||knight knight: Black has the threat 24...Qc2+ 25. Ka1 Qc1+ 26. Rxc1 Rxc1#. Let's look for the best way to stop this:|
a) (obvious blunder category) 24. Nc5/c3/d2??, 24. Rc1/d2??, 24. Qe2/f4??, 24. Qxg7+??, 24. Ka1??
b) 24. a3 this is effectively giving black a tempo to defend, altho it's here I notice that white's attack is very strong indeed
c) 24. a4!? is like 24. a3 but leaves the pawn undefended
d) 24. b3!? Qc2+ 25. Ka1 this is like 24. a3 in that it's giving black a tempo
e) 24. b4!? is like 24. b3 but leaves the pawn undefended
f) 24. Bc3? f5 this appears to win a piece for black
g) 24. Bg5? hxg5 action on the h-file but it seems white's just dropped a piece
h) 24. Rc3 looks like the best defence, analysed below
i) 24. Rhh1 looks like a backwards step for white's attack
j) a defence I've missed
In response to 24. Rc3, black can play:
1) 24...Ne5 25. Bxe5 f5 26. Nf6+ Kh8 27. Qxc4 Rxc4 28. Nxe8 lots of material ahead
2) 24...Qxe4+ 25. Qxe4 Nxf6 26. Qxb7 Rxc3 27. bxc3 queen for two minor pieces
3) 24...Qb4 25. Rxd7 Rxc3 27. Bxc3 piece ahead (27...f5?? 28. Nf6+ Kh8 29. Qxb4 Bxb4 30. Nxe8)
4) 24...Qa4 25. Bxg7 Bxg7 27. Nf6+ Nxf6 27. Qxa4 queen for two minor pieces (this line also works in response to 24...Qb4)
5) 24...Qa6 the 25. Rxd7 line above
6) 24...Qb5 25. a4! Qb4/xa4/a6 and back to the lines above, if 25...Ne5 26. Qg3 winning a piece I think
7) a defence I've missed
Time to see what happened...
|Dec-03-10|| ||gofer: <David2009>
Against Crafty EGT, after 40 moves I can get to the following position.
click for larger view
24 Rc3 Qb5 (forced)
25 Rxd7 Qxd7
26 Bxg7 Bxg7 (forced)
27 Nf6+ Kh8 (forced)
28 Nxd7 Bxc3 (forced)
29 bxc3 Rc7
30 Nf6 Rec8 (forced?!)
31 Qf4 Kg7 (forced)
32 Ng4 Kf8 (forced)
33 Qxh6+ Ke8 (forced)
34 Kb2 Rxc3 (forced?!)
35 Qh8+ Ke7 (forced)
36 Qxc3 Rxc3 (forced)
37 Kxc3 f5
38 Ne5 Kf8 (forced)
39 f3 Kg7
40 g4 Kh6
which is pretty well over, but yes it does take a while. <Thanks for taking the time to set up the link>.
|Dec-03-10|| ||zabbura2002: Black played 2 consecutive moves on move 22 and 23 (actually on move 24 too!) to create a chance for triple-forks. Not to the opponent but for herself to be forked.. and also leaving the Knight unguarded.
Too focused on the attacking I guess|
|Dec-03-10|| ||Auguste: 24. Rc3 is sort of forced, because black is threatening Qc2+ and then Qc1+.
after black's queen move like 24... Qb5, 25. Rxd7 is easy to find.|
|Dec-03-10|| ||twin phoenix: oddly enough i got this one fairly easily... just notice that Black threatens Q-c2+ and then mate and ask yourself how do i is solve this dilemma? the retort 24. r-c3 so effectivly stops all of blacks threats that white will be free to play such moves as 25. Rxd7. easy... The hard part, of course, is checking all tactical situations to make sure it is winning.
yay i finnally got a friday!!|
|Dec-03-10|| ||kevin86: With black to move in the puzzle position,it's a Monday mate in three with a queen sac. With white to move,24 ♖c3 is a must!|
|Dec-03-10|| ||Patriot: I didn't spend much time on this and went with 24.Rc3 after I saw the mate threat. I decided it was safe to play and it produced counter-threats which looked interesting.|
An efficient thought process might go like this...
"White is not in check and I don't see an immediate mate that white can deliver, so let's start by examining material differences and see if black has any threats."
* Material and threats by black do not matter at this point, since if white has a forced mate he should just deliver it!
"First, black threatens 24...Qc2+ 25.Ka1 Qc1+ 26.Rxc1 Rxc1#, so the only good candidates for white are the one's that address this issue. Also, there doesn't seem to be any more threats."
* When looking for threats OTB, make sure you look at ALL threats in the position--not just threats generated by the piece that moved.
"Before going further I should look at material differences since they play a direct role in analysis. White is down a pawn."
* Whenever one side is up material, the likelihood of sac'ing material back increases--especially when there is a strong attack against them. Otherwise they may be dropping material without compensation which would be a waste of time to analyze unless there were further checks, captures, or threats to examine.
"Now to look for candidate moves. Black has a killer move, 24...Qc2+ which must be addressed. 24.Rc3 is a very strong move, attacking the queen and also threatening 25.Rxd7 in some lines. 24...Qxc3 25.bxc3 is good for white, and I don't see other moves that refute 24.Rc3 so it is safe. 24.Bc3 f5 looks menacing for white. 24.Nc3 Qxg4, so that's not safe. 24.a3/b3 may give black time to consolidate although I'm not sure what he can do at this point. 24...Nxf6 25.Nxf6+ Kh8 26.Qxc4 Rxc4 27.Nxe8 looks good for white so there's no harm there."
* When considering candidates, it's usually best to look at the strongest moves first.
* A "safety test" must be performed on each without going into a lot of detail. If you can determine early that a candidate isn't safe, it can be quickly eliminated to save time.
* Going into a lot of detail on any candidate is a mistake at this point since there could potentially be a killer candidate that wins on the spot. Otherwise you may be wasting a lot of time.
"24.Rc3 looks like the strongest candidate with multiple threats against black as well as stopping black's threats. At this point if I don't have much time I could go ahead and play this move since there aren't any other moves that look promising. Otherwise I may want to look at this further. 24...Qxc3 25.bxc3 . 24...Nxf6 25.Nxf6+ Kh8 26.Rxc4 . So black must protect the queen while defending the knight on d7. 24...Qa4/Qb5 25.Rxd7 Qxd7 26.Nf6+ Kh8 27.Nxd7 wins the queen. But if 25...Kh8, now both the rook on d7 and bishop on f6 are hanging. White is at least ok if he retreats the rook but is still down a pawn."
I'm going to end it there.
|Dec-03-10|| ||goodevans: <rilkefan: "24...Qa4 25 Rxd7? Rxc3! 26 bxc3" |
Why not 26.Bc3 instead?>
<tacticalmonster: < rilkefan > yeah a hallucination. I thought after 25 Rxc3 26 Bxc3 Black can play 26...f5 forking N and Q but I overlooked that White can play 27 Nf6+ winning the queen.>
... or 27 Rxg7+ winning the King!
|Dec-03-10|| ||Patriot: I made at least one mistake. At the bottom where it reads "24...Qa4/Qb5 25.Rxd7 Qxd7 26.Nf6+ Kh8 27.Nxd7 wins the queen." is actually incorrect since the bishop is on f6. 26.Bxg7 as <dzechiel> mentioned looks like the winning move.|
Sorry for the lengthy post. Hopefully it helps some of the kibitzer's on this site.
|Dec-03-10|| ||JG27Pyth: I usually insist that I solve out the puzzle from the diagram but today I thought, Rc3 is right, and if he wants to keep his N, he'll need to work out whether his Q belongs on a4 or b5... so why don't we let him think on <his> time ;) -- then I guess-the-move'd it from there. 100% on the g-t-m. But I'm pretty sure trying to calculate/visualize up to Rxf7 with confidence from the first position would eat up a huge chunk of clock and there's always the chance I confuse myself and chase a purple rabbit into the bushes of defeat.|
|Dec-03-10|| ||goldenbear: I had this one worked out, but I considered 24.Qxe4 to be the main reply.|
|Dec-03-10|| ||JG27Pyth: Oh, btw <Once> I disagree that Rc3 isn't a move that 'smites'... it's defensive, ok, but it's defensive, <with privileges> as the kids say ;) Removing the mating threat down the c-file activates the threat against d7 -- a smite, non?|
|Dec-03-10|| ||patzer2: For today's Friday puzzle solution, we were treated to a winning combination by Chinese GM Yuhua Xu from a game which helped her to win the 2006 FIDE Women's World Championship.|
Yuhua's 24. RC3! (today's Friday solution) combines a number of tactics in her winning combination, including a poisoned pawn trap (23. Rh3!), defensive combination (24. Rc3!), deflection (24. Rc3!), decoy sham sacrifice (25. Rxd7!), a Pin and Knight Fork threat (e.g. 25...Qxd7 26. Bxg7 f5 27. Nf6+ Kf7 28. Qg6+ Ke7 29. Nxd7 ) and an overwhelming mating threat (26. Rxf7!).
On the surface, the puzzle solution 24. Rc3! is a simple defensive move designed to stop the back rank mate threat after say 27. Bxg7?? Qc2+ 28. Ka1 Qc1+ 29. Rxc1 Rxc1#.
However, on a deeper level, it springs the trap set after 23. Rh3!, when the only saving reply is 23...Nc5! = with about even chances. Earlier, 21...e5! = was an even easier way to equalize.
Instead, after the blunder 23...Qxc4? (falling into the trap by taking the poisoned pawn), Yuhua springs the trap with the decisive 24. Rc3!, when 24...Qb5 (or 24...Qb4 25. Rxd7 ) 25. Rxd7! (not 25. Bxg7?? Bxg7 26. Rg3 Qe5 ) wins a piece due to the dual threat of mate or a Knight fork after 25...Qxd7 26. Bxg7 .
If 25...Rxc3, then simply 26. Bxc3 leaves the Rook on d7 untouchable due to the pin and knight fork threat, winning the Queen after 26...Qxd7 27. Nf6+ Kh8 28. Nxd7 with decisive material advantage.
In the final position, White threatens a number of mates, including a simple mate-in-two (e.g. 26...Rxc3 or 26...Qf5 yields 27. Rxf8+ Rxf8 28. Qxg7#) or mate-in-three after 26...Re7 27. Bxg7+ Kg8 28. Nf6+! Kxf7 29. Qg6#. Black can prolong it with spite checks or by sacrificing the Queen, but with strong play the mate is unstoppable.
|Dec-03-10|| ||tacticalmonster: <David 2009> |
click for larger view
29...Rc7 is a weak move because Black drops the exchange in a four-move combination: 30 Nf6 Rec8 (or 30... Ree7?!) 31 Qf4 Kg7 32 Ne8+! Rxe8 33 Qxc7. However, it is hard to suggest any move for Black at all on the 29th move.
|Dec-03-10|| ||Brandon plays: Black seems to defend rather well using crafty or else my attacking skills suck. It took me like 60 moves to checkmate though it was a won position.|
|Dec-03-10|| ||Once: <JG27Pyth> I suppose it depends on your definition of "smite". I think the term was first coined by Purdy who said that we should "examine moves that smite".|
I have always taken a smiting move to be a violent one that forces a reply, such as check or a capture. The dictionary definition is to inflict a blow, to hit, to cleave.
Does 24. Rc3 hit or cleave? I don't think so, but 25. Rxd7 certainly "smites".
I suppose like many other things in chess it comes down to personal preferences. I don't think that 24. Rc3 is the usual type of solution for the CG puzzle, but if you do then that's perfectly fine by me.
|Dec-03-10|| ||M.Hassan: <scormus: I think mot of us can say the same......> Thank you and it is indeed cosoling to hear this from a persistant and regular kibitzer with such good explanation.|
|Dec-03-10|| ||David2009: <gofer>, <tacticalmonster>: Congratulations! |
Your line with 31 Qf4! is much faster than 31 Qd4 which also beats Crafty EGT (reaching an ending N for P up in the main variation). Earlier post:
Y Xu vs A Ushenina, 2006
<Brandon plays:> Congratulations - a win is a win! The EGT has a knack of finding unexpected resources in positions that look hopeless.
|Dec-03-10|| ||WhiteRook48: i wanted 24 Bc3 instead|
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