< Earlier Kibitzing · PAGE 4 OF 4 ·
|Feb-05-09|| ||Marmot PFL: Without calculating all the way to mate after Qxb4+ ab Rxb4+ it is clear that with the pawn on c3 the white king cannot escape. He did find a way though, Qd8+, which i didn't expect, but this just prolongs the agony.|
|Feb-05-09|| ||Jimfromprovidence: FWIW, here's an eye-pleasing forced mate if white had played 26 Ka1 instead of b4.|
click for larger view
26...cxb2+ 27 Kb1 Ba2+ 28 Kxa2 bxc1N+! 29 Rxc1 Qb2#.
click for larger view
|Feb-05-09|| ||Zzyw: Easy for a Thursday. Straightforward, forcing, and no good defensive tries for white, who could have resigned a bit earlier.|
|Feb-05-09|| ||Jack Kerouac: A 'Volt' from the blue!|
|Feb-05-09|| ||TheaN: <whiteshark & Patriot: about 'easy-to-spot-but-hard-to-finish'>|
Well, the follow-up was not necessarily that difficult, but the fact that the ONLY move against White's mate threat is Qxb4† makes that move very easy to spot, and only then the calculation starts. And to be honest, without the combination going as far as 29....Rdb8 the Black gain is not sufficient, proving that the follow-up is definitely more calculation sensitive.
<Patriot: In my opinion, it's not necessary to calculate all the way through to mate on this.>
IMO, yes and no. Even though Black has sufficient material after 30....Rxd8, the mate is still very much in the air, and Black has clear initiative. Mate might be a bit too much (as it seems to be mate in 5 after 30.Qd8†) at that point, but moves like Rdb8 and Bc4 are somewhat necessary to spot to solve the puzzle. They either simplify ALL pieces leaving Black a full Knight and two pawns up, or they lead to mate. When Black softens up White might still get away in some miraculous way.
|Feb-05-09|| ||YouRang: I got this fairly quickly. Even though it involves several moves, they are mostly forcing. |
The key move, <26...Qxb4+!>, even though a queen sac, readily suggests itself due to the amount of force (2R+B+N+P) directed at white's K position, plus the fact that the white king appears to be hemmed into a "corridor of death" by his own pieces.
After 26...Qxb4+!, then <27.axb4 Rxb4+>. White cannot play 28.Kh1 due to 28...Ra4+ 29.Rb8+ ~#.
So, the bishop-losing <28.Bb2> is forced to block check and make an escape at c1, and then <28...Rxb2+ 29.Kc1 Rdb8> (threat:Rb1#)
To avoid mate, white must jettison his queen just to buy some time: <30.Qd8+ Rxd8>, but we know that rook is heading back to b8 to renew the mate threat.
White must now vacate d1. He could try 31.Rd3, but that obviously loses the h1 rook to a skewer. But trying to avoid the skewer with <31.Rf1> doesn't help: <31...Bg4!> (sealing off e1 escape square) <32.Rf3> (must block bishop, but now Rh1 is again vulnerable to the skewer) <Rdb8> (threat:Rb1#) <33.Ke1 Rb1+ 34.Ke2 Bxf3+> (gaining exchange with check), and <35...Rxh1> next (winning the the other rook).
Black has such a vast material advantage that, apart from masochistic pleasure, white has no motive to play on.
|Feb-05-09|| ||Patriot: Thanks <TheaN> for your reply. I always enjoy reading your analysis and comments.|
I would bet 9 times out of 10 that if you asked a master to analyze the puzzle position, they would stop analyzing after 29...Rdb8. I've been getting lessons from a master for several years and I would guarantee that is where he would stop. He told me once that his teacher years ago (IM Donald Byrne) asked him what he was analyzing in a position where he was a piece up. He said he was trying to find out if there is a forced mate. Byrne replied "Don't! You're a strong enough player that any grandmaster would resign against you in this position!" It's important to know when to stop analyzing or else get into unnecessary time trouble OTB. But even in a puzzle position, analyzing past a technical win is unnecessary and may even be bad practice if you are analyzing for the purpose of becoming a better analyst OTB. It's also important not to stop analyzing when there is counterplay possible after an advantage in material. But in this position, white has nothing after 29...Rdb8 30.Qd8+ Rxd8 so there is really nothing more to consider.
Many tactics problems in books do not follow thru to mate, but end in winning a piece or even a pawn to be considered solved.
|Feb-05-09|| ||Once: There is a surprisingly interesting position at the core of this puzzle:|
click for larger view
The c3 pawn does a very effective job of restricting the white king's escape. If black has a pair of rooks (or rook plus queen) to check on the a and b files, white can find himself with no way out. The king has to march to c1, d1 and then e2 to get off the back rank. This gives black the time he needs to get his heavy pieces into position.
And all this from a single black pawn.
|Feb-05-09|| ||MiCrooks: This was pretty easy for a Thursday. White's threat of Bh6 means Black needs to get there first. So Qxb4 is really the only move I looked at, and after looking at it briefly it was pretty obvious that it works. Sure White can and did squirm, but in doing so he gives back more material that Black had to commit, so not a lot of thought needs to follow that!|
As for anticipating Bb2, sure you look at it, but it's a two mover with the first one being absolutely automatic Rxb2+. Ka1 is immediate mate with Nb3++ so that only leave Kc1 when you move your Rook that is hanging and threaten mate again forcing a Queen sack back. At that point you can quit it you want. You are easily winning this game even if you don't notice that you can still force mate!
|Feb-05-09|| ||zb2cr: Okay, I saw the Queen sacrifice 26. ... Qxb4+; 27. axb4 (moving the King or interposing the Bishop leads to mate in 1), Rxb4+; 28. Ka1, Ra4+; 29. Kb1, Rb8+; 30. Bb2, Rxb2+; 31. Kc1, Ra1#. |
However, I never even considered the defense of 27. Bb2. So, I think, only half credit for me.
|Feb-05-09|| ||ruzon: <Once: And all this from a single black pawn.>|
Don't forget the single white pawn. If c2 is empty or occupied by a piece that can move, it's an entirely different situation.
|Feb-05-09|| ||WhiteRook48: whoa, white got shocked from volt|
|Feb-05-09|| ||eatitorbeatit: I am a 8 year old genius who solved this problem with the help of my Daddy John L Spouge!!!!!!!|
|Feb-05-09|| ||Jim Bartle: Congratulations, eatit.|
|Feb-05-09|| ||johnlspouge: Whereas once I was embarrassed by my parents, now I am embarrassed by my children...|
Wish me luck (:>}
|Feb-05-09|| ||Jim Bartle: You didn't name him Magnus or Wesley or Sergey, did you?|
|Feb-05-09|| ||eatitorbeatit: I AM NOT A BOY!!!!!!!!! I AM A GIRL! Oh, and thanks! :)|
|Feb-05-09|| ||Jim Bartle: Sorry. See, my innate biases come out.
Your name isn't Yifan or Judith, is it?
|Feb-05-09|| ||johnlspouge: Hi, <Jim>. As you can already see, I have my hands full here. My daughter thanks you for her warm reception at chessgames.com and is now off to bed (I hope :)|
I really enjoyed your bio. I hope I never get a winning position against you ;>)
|Feb-05-09|| ||johnlspouge: Go to bed !@!#$@!|
|Feb-05-09|| ||Jim Bartle: A chessgames first.|
|Feb-05-09|| ||DarthStapler: Got it|
|Feb-06-09|| ||Once: <eatitorbeatit> Welcome! The natives are very friendly here ... but watch out for the nasty sunday puzzles.|
Can you explain your handle please? Has it got something to do with eggs or do you like Michael Jackson?
|Feb-09-09|| ||TheaN: <Patriot>
Valid point there: I'm somewhat notorious for my continuous analysis in positions where this is seemingly not necessary. Nonetheless, it has a pro and a con.
The con you described clearly; give your opponent the idea you're still playing for a combination with a piece up and he might try some defense to win material back and/or draw in classic ways. Play like you're a piece up and he will, probably, resign quickly.
The pro is less obvious. If I'm in a position like the one above, with 5 or less minutes to play with, I'd rather chase the king on with the obvious moves 31....Rbd8 and 32....Bc4. After 33.Bd3, investing ~30 seconds to a minute to find a clear continuation could win the game early, whilst playing on by retreating the Knight could lead to a flag loss.
Both have their merits, but having quite some position knowledge with such combinations is necessary, and for that training is needed.
|Oct-20-12|| ||JENTA: I would rather play 14. Bc4
(instead of 14. Nc4).
Black's Be6 feels dangerous.
White's manouvre Nd2-c4-d6 seemed to be artificial.
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