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mattdw 192 ( +1 | -1 )
A question from an old Novice Nook. I'm still catching up with these (reading #15-25 in various order at the moment) and I have a question about something that was in "#15 - a counting primer". In the following example he is using the Kaufmann values (P=1, N=3.25, R=5, Q=9.75) and I don't quite follow what he is saying:

Quote: "The following is an example of an exchange sacrifice that strong players make routinely but weak players often do not even consider:


The above position is from Keres - Bronstein, Moscow 1956, with Black to move. Bronstein continued 18…Rxf3! 19. gxf3 Nxd4 and already Black is a little better, not “down a pawn” as a simple “rook is worth 5, knight plus pawn worth 4” evaluation
would have you believe."

With the Reinfeld values black would be "down" a pawn: 5 - (3+1) = 1
With the Kaufmann values black would still be "down": 5 - (3.25+1) = 0.75

So why does he say that black is already a little better? He is down under both material counting systems, I don't know whether I should be reading more (or less) into the board position (it is the Novice nook afterall!) - is he taking into account the doubled isolated pawn island. If so, I would have thought he would have mentioned that seeing as the article is about counting and not evaluation (...thinking maybe the future capture of the f3 pawn? Incedentally the actual game ended in a draw 4 moves later with no recapture!). White's next move was Nc3 which removed the opportunity for the deflection of the overworked queen from the defense of a4 after Nxf3, so I'm really quite stumped as to why black is better. I tried putting the position into Fritz and it agreed that Rxf3 was the best move. Any ideas? I'm not entirely sure what it is that I'm not getting!



Thanks,

Matt
ccmcacollister 456 ( +1 | -1 )
MATT ... I'm still bleary for tree analysis, so I wont attempt to state what happens next here, but just mention some factors and see what you think. If added together and which may apply :) Ok? This is not too unusual Frenchy stuff. [I once won a Linc corr game vs Steve Ahlstrom, a 23oo+ish Master from Mo. after he made a similar sac. Difference was no N hung out on a4 and WT could activate his Rooks usefully immediately.] In this diagram I assume there s/b a Rook on f1, as nothing could have taken it from there reasonably...and Kg1?
***
1)The immediate tactic that the Na4 is threatened so looks like another pawn will come off at f3 if the QN gets saved. (Which is also what Fails a Bxh7+ try there).
*
2)All the BL pieces now have rapid access to the K-side where he will probably attack, or to central lines. And WT trying to attack on the Q-side as traditional here, just pushes BL pieces to where he wants em anyway, even faster! And if WT does get into the BL Q-side, which is pretty weak really, like ...b7, BL could probably passive sac everything there if needed and only worry if he might lose to an endgame materially or Queen being made there, but not that WT could use lateral lines to staunch a BL K-side assault. It looks to me that any attempt to do that would have to be from the front here.
3) In that vein, the QR will soon become the KR, and all BL's pieces are participatory. The very Rook he gave up, can be immediately replaced. In short term attacking view, it is almost like he gave NOTHING for the Nf3 and everything he gained.
4) About Wt B's/& Again that Rook a bit. Or rather the one given up... Normally in a position where the opponent has a 2-Bishop pair, the play given to two Rooks you possess may be more and more hindered as you open a position up. The importance of WT's B pair here may now be "reduced" in two ways. A) Since there is only one Rook left for BL, WT cannot get as much B play AGAINST Rooks! as he might have
(eh? :)
(5) But also here, the mere existance of BL having the only two Center Pawns now may further hamper the usefulness of the B-pair, besides being a Plus in themselves that you are well aware of. And if/when the center goes mobile then the Bd3 may further be a target of them, as well as the N-returning to Nc3. &
the Bg3 may be subject to K-side pawn advances, or elimination the the BL N if he does not make a place for it. Hopefully Be5 before a pawn roll, since it just aint pretty if it ever goes to Bh2. Not where it dreamed of being when it grew up....
Another matter of that center, BL has an option to keep it static to control the center and try wing attack instead.
**
(6) The Kingside WT Sq's are decimated. No other word. So as WT I might well be
thanking the Pope or any of 18 Protestant ArchBishops that among them, Someone thought to leave me a WT Sq Bishop! :) Fortunately Wt may lose his f3 pawn so we dont have to count the double isolani against him, if so :) As you note- that is the worst possible formation for two pawns to have. It may hold, but try to say there is not a Better way for them to be in whatever posiiton?! Usually it is the most subject to frontal attack, cannot make a passer in an ending thus worthless.
(EG imagine this came down to RvsR ending with these pawns- who's winning?)
Also, having a larger # of islands is in general worse than not having as many.
**
(7)The BL Bishop pair are in tandem. Wt are not. Also the BL pair can prevent infiltrations of WT Rooks on the open c-file. Practically useless if WT ever got the chance to double there, or even place Rc1.
(8) In an attacking sense, for WT... what will you do. Suppose go after the Q-side.
Would you then prefer to go after the weakness of BL's 2nd rank pawns there, with pieces? Queen aor minors? Letting your two Rooks sit and do nothing? Or should we put the WT Rooks behind pawns there and push them to try and open another file so we can use them to attack the, um the ... well the BL pieces that are no longer there and are all on the K-side? Let's not do that since there is no forcible line opening Sq there anyway. (To open you must have an immobile object that can be attacked or Sq where two objects can be attacked simulateously ... or a sac that must be accepted)
(9) Because Soviet players have always been well versed in handling a "Russian Exchange" from the small-side. And worse yet, because BL is Bronstein ! Who you just dont wave a red flag in front of and not expect a charge. :) haha
*********
That's all I have off the top of my head right now ... So Please everyone, someone;
go ahead and tell my that WT won this game in a Brilliancy Prize massacre'(?!?) and
I'll just slink off into the night . . .
ccmcacollister 104 ( +1 | -1 )
ouff .... I new there would be some biggee I missed right away! Consider also the places that WT's pawns have made Nimzovich happy ... the h-file but more the f-file can both have pieces blockade (blockade?! Like those pawns might Go somewhere, except "AWAY"?? ...Ok, Revel in their possession of then, let us say ...)
ALSO WT has Two Knights; yet [all Jeremy Silman fans may applaude here...] we are simply innundated with IM types, whether gruff and concerned or simply bad-tempered(!?:) ....who will tell us endlessly that for knights to be effective they Must have outposts; especially Central or Forward outposts. Yet with the BL center, especially if it starts to roll down the yellow brick road there, ... where do WT Knights post in the Center? Or in an advanced SQ?
Worse than that, they look to become the dogs that get kicked, not just have no home ...
Just some thoughts. AND I may be wrong (because, I got all this from Dennis Miller! Just Don't tell him I said so tho ... )
ionadowman 116 ( +1 | -1 )
mattdw... ... if you want to see something similar, check out board #4642297. The game is now drawing to a close after 70-odd moves. At move 18 the normal moves seemed to lead to drawish, or at least very technical endgames. The speculative exchange R for N+2P, especially as it left Black with an enormous centre majority seemed to offer best chances for a decisive result. White kept his B-pair, but they didn't seem to balance that pawn centre, even when BK gave up his a-pawn later on. Though I like the B-pair in season, I still reckon they are overrated in general. The Black Knights proved to be excellent protectors and supporters of a general advance of black's pawn phalanx.
(I have a particular fondness for 'asymmetrical material' games. This one turned into an epic battle)
Otherwise, Craig has pretty much summarised Black's assets in the position you have given (bearing in mind the Rf1 and Kg1, instead of the Kf1 ... a typo?). My first thought was the pawn centre, but there is no doubt Black has K-side and other assorted tactical chances as well.
mattdw 208 ( +1 | -1 )
Thanks! :) Ah yes, the board was slightly wrong! (cheers craig :)):
Correction:

The actual game can be found here:
-> www.chessgames.com

Ok, so after
18...Rxf3
19. gxf3 Nxd4
20. Nc3 ...we have:


Is there another tactic involving the knight which was at a4 that I am missing? I'm not sure how black could immediately capture the f3 pawn via a forced sequence. I see what you mean about black having more prospects of an attack on the kingside (which I agree with), Dan, however didn't mention this (edit: or any of the other positional factors!)! It seems strange in an article based on counting, aimed at novices, to have an example where positional factors are taking into account but not even mentioned! I'd never really thought about the Bishop/rook thing you mentioned in #4, but in retrospect I remember having trouble in a game with a situation where that came about - I should really have learnt a lesson from that...I must be more vigilant!

I now see how all the positional factors seem to be in Blacks favour, I didn't really pick up on much of it myself the first time round apart from the pawn structure - if there is one area of my game which is exceptionally weak it is my strategic knowledge (which I will start working on seriously when I finally cease to lose my games due to catastrophic tactical errors!). Many thanks for the thoughts in this area, it is much appreciated!

Very interesting game Ion! Isn't it R for N+P rather than +2P? I like the idea of 'losing the exchange' (from a purely materialistic view) to get something less immediately tangible as a very strong pawn centre (or piece activity etc..) which can be used to gain an advantage in the future.
ionadowman 100 ( +1 | -1 )
You are right, Matt... ...the immediate exchange was R for N+1P, but White had gambited a pawn very early in the game. That I was already a pawn ahead was a consideration! I doubt I would have gone in for it otherwise - in that particular game anyhow.
I've had a look at the Keres-Bronstein game - a bit of a torso really. I prefer Black in the final position, but it doesn't look easy to arrive at any knid of plan. Keres seems to have shored up his K-wing effectively, and Black's centre pawns are for the time being immobilised.
I was a bit surprised by 20...Bf6, but it looks as though Black has to meet the threat of 21.Bxh7+ Kxh7 22.Qxd4 I wonder if 20...Nh6-f4 has anything against it? Maybe 21.Be5!? As for any tactic against the N on a4, it seems Keres's 20.Nc3 was timely. Black can't really get anything in before then. If at move 18 Black tries an immediate 18...Nxd4 19.Nxd4 Bxa4 20.b3 Be7 21.Nxe6, threatens 22.Nxf8 or Nxg7, and leaves Black with an isolani on d5. But seems, too, that 22.b4 or 22.Bc7 are also threats black is faced with. Something to thing about anyway...
Cheers,
Ion