Originally posted by David113 [fen]8/2Nb4/pp6/4rp1p/1Pp1pPkP/PpPpR3/1B1P2N1/1K6 w - - 0 1[/fen]
Mate in 5. Black has an unusual defense against White's threat...
1.Kc1 intending to walk the K over to f2, followed by Rg3# 1...Ba4 2.Kd1 Ra5! planning 3.Ke1? b5! 4.Kf2 stalemate. 3.b5! Interference. White menaces Ne8-f6# and Nd5-f6#. Black can only parry one of the threats. 3...Bxb5 4.Nd5 ~ 5.Nf6# or 3...Rxb5 4.Ne8 ~ 5.Nf6#
Originally posted by SwissGambit [b]1.Kc1 intending to walk the K over to f2, followed by Rg3# 1...Ba4 2.Kd1 Ra5! planning 3.Ke1? b5! 4.Kf2 stalemate. 3.b5! Interference. White menaces Ne8-f6# and Nd5-f6#. Black can only parry one of the threats. 3...Bxb5 4.Nd5 ~ 5.Nf6# or 3...Rxb5 4.Ne8 ~ 5.Nf6#[/b]
I don't see why it's salemate after 4.Kf2. The black rook can move to a4 and the bishop can still move along the a4-e8 diagonal.
Originally posted by Nicky4815 I don't see why it's salemate after 4.Kf2. The black rook can move to a4 and the bishop can still move along the a4-e8 diagonal.
There's a Bishop on a4, so the Black Rook can't move there. There's a pawn on b5, so the Bishop can't move either.
Originally posted by SwissGambit [b]1.Kc1 intending to walk the K over to f2, followed by Rg3# 1...Ba4 2.Kd1 Ra5! planning 3.Ke1? b5! 4.Kf2 stalemate. 3.b5! Interference. White menaces Ne8-f6# and Nd5-f6#. Black can only parry one of the threats. 3...Bxb5 4.Nd5 ~ 5.Nf6# or 3...Rxb5 4.Ne8 ~ 5.Nf6#[/b]
You have a strange notion of 'duals'. You seem to think that any dual is necessarily a flaw.
Why should we worry about duals after moves like 1...a5? That's not even a defense - it does nothing to stop White's threat. Same goes for 1.Kc1 Ba4 2.Kd1 Bb5?
In the main lines, i.e. the ones where Black actually tries to stop White from carrying out his threat, there are no duals. Your objection is overly pedantic and your idea that "every dual is a flaw" would cause many classic chess problems to be scrapped.
Sigh. There certainly are differing attitudes towards duals, as one can see in the English and German school debates, and the Bohemian school, but any problem in which so many continuations lead to the same end is riddled with duals; just as in statistics, you cannot throw out something you don't like and call it an outlier just because it is more convenient; here you can't throw out the many duals (they arise even after 1. ... Ra5 Rxa3,Ra1+ etc, which is the reason a bishop is needed on b2 instead of a P) that occur here, especially in the next to last move. If you doubt me, contact John Rice or another authority; I've been through this with him several times on problems of my own and some in the Supplement. I can't see this problem being published anywhere due to its flaws.
I'm not here to argue, just point out that it is not a very good problem on many levels - obvious key, tons of continuations leading to the same dual mates of Sf6 and Rg3, etc.
And since I am not here to argue, I'll leave it at that..... If you want to remain convinced that you know better, that's fine by me. I have problems to submit...
Originally posted by Helpmate29 Sigh. There certainly are differing attitudes towards duals, as one can see in the English and German school debates, and the Bohemian school, but any problem in which so many continuations lead to the same end is riddled with duals; just as in statistics, you cannot throw out something you don't like and call it an outlier just because it is more conveni ...[text shortened]... to remain convinced that you know better, that's fine by me. I have problems to submit...
I'm not throwing out anything. I'm saying that duals in variations arising from non-defenses shouldn't be considered a flaw.
Deciding what constitutes a flaw is more an aesthetic decision than a mathematical one.
I see no dual in the line: 1.Kc1 Ra5 2.Kd1 Rxa3 3.Nd5 [White has no other move that works] 3...Ra1+ 4.Bxa1 ~ 5.Nf6#
This problem was in fact published in Deutsches Wochenschach, 1904.
Oh my for that day, certainly such a problem would be accepted. And we can accept it as it is, recognizing the duals. After all the Codex is clear:
Article 10 - Dual
(1) Subject to paragraph (2), a dual is said to occur if, after the first move, there is more than one method of satisfying the stipulation.
When I publish classic problems in my columns or articles, I often note such duals, but you are correct, in the context of time, one must consider them minor blemishes. Today....
What would be great is if a dual-free or relatively dual-free version could be composed ...
Perhaps we were not as far apart as we assumed, and you know what they say about assume!
Originally posted by Helpmate29 Oh my for that day, certainly such a problem would be accepted. And we can accept it as it is, recognizing the duals. After all the Codex is clear:
Article 10 - Dual
(1) Subject to paragraph (2), a dual is said to occur if, after the first move, there is more than one method of satisfying the stipulation.
When I publish classic problems in my co ...[text shortened]... ...
Perhaps we were not as far apart as we assumed, and you know what they say about assume!
My point all along has been that duals outside of variations generated by Black defenses should not be recognized, or treated as flaws. The main exception is problems that operate on zugzwang rather than threats.
I will try to find some modern counterexamples that show a similar lack of concern about duals in lines that aren't Black defenses.
didnt even have to read it all, to see helpmate is seeking for some attention. the puzzle was nice and satisfying for any puzzle lover and i dont know what duals he is talking about 🙂
Mate in 5
17 May '07 12:531 edit
Back to Top