The Chess Exchange

The Chess Exchange - To Your Chess Success!

Skip to content

It is currently Wed Sep 20, 2017 12:59 pm 






This topic is locked, you cannot edit posts or make further replies.  [ 9 posts ] 

Previous topic | Next topic 

  Print view

Author Message
 Offline
Pawn
 
Joined: Mon Sep 03, 2007 5:25 pm
Posts: 6
 Post subject: Mate in two?
PostPosted: Fri May 21, 2010 6:42 am 
The following is one of ten "mate in two" puzzles in the chess program I have on my cell phone. I've looked at this puzzle for hours, but I don't see a way for white to mate in two moves.

Image

What am I missing?


Top
 Profile  
 
User avatar  Offline
King
 
Joined: Sat Aug 13, 2005 3:13 pm
Posts: 304
Location: Finland
 Post subject: Re: Mate in two?
PostPosted: Fri May 21, 2010 8:43 am 
You have missed the clever 1.Rh8!
Problem is from Z.Mach in 1889.
Seems they could compose faster than sound already then. :shock:

There are severral nice variations. Check them out!


Top
 Profile  
 
 Offline
Pawn
 
Joined: Mon Sep 03, 2007 5:25 pm
Posts: 6
 Post subject: Re: Mate in two?
PostPosted: Mon May 24, 2010 4:09 am 
It seems so obvious once someone explains it. Thanks.


Top
 Profile  
 
User avatar  Offline
Site Admin
 
Joined: Thu Sep 04, 2003 12:42 am
Posts: 1430
Location: Utrecht, The Netherlands
 Post subject: Re: Mate in two?
PostPosted: Thu May 27, 2010 6:16 pm 
mrmip wrote:
You have missed the clever 1.Rh8!
Problem is from Z.Mach in 1889.
Seems they could compose faster than sound already then. :shock:

There are several nice variations. Check them out!



I have a composition in one of my endgame databases; I've written at the end of the annotation that it's by Z. Mach (what the hell stood that Z. for? I've never found out!)
I really don't know if that's the case. I used it as an example that by far not all modern chess engines are able to find the quickest mate for white. Maybe that's a good sign, because in that respect they start to mimic humans. Most go for Qc5 which was my first solution as well, as it seems so obvious.

Here's the position, maybe you know if it's really a composition by Mach:

8/2Qp4/5p1N/5p2/2p1k3/r1p5/4bK2/3R4 w - - 0 1

W Kf2,Qc7,Rd1,Nh6
B Ke4,Ra3,Be2,c3,c4,d7,f5,f6
Mate in three.


Top
 Profile  
 
User avatar  Offline
King
 
Joined: Sat Aug 13, 2005 3:13 pm
Posts: 304
Location: Finland
 Post subject: Re: Mate in two?
PostPosted: Fri May 28, 2010 3:22 pm 
Hello Jeroen,

It may come as a surprise for you, but the Z comes from the composer's first (possibly second?) name. We have Mach,Zdenek and Mach,Julius Zdenek who appear to be the same early Czech (Bohemian really) composer. More interestingly the minature twomover appeared in "Nove Parizske mody"-publication along with several of it's variants - probably right alongside with the the add for latest Parisian lingerie. :). It appears that this publication was very popular among the Czech problemists around 1900. Cross-dressers all of them, I say.

The threemover You asked about is really composed by Zdenek Mach and appeared first in "Das Schachfreund" in 1896 winning an honorary mention. It is a crafty composition, where the black rook cannot do much to prevent the mate. I liked the variation 1...f4 best.

Just for the record I know of at least three freely available, searchable problem databases in the net, where you can possibly find the name of a composer if you know the position (and the otherway around). These are

(1) Problem data base (PDB) http://www.softdecc.com/pdb/index.pdb maintained by Gerd Wilts. This is great especially for helpmates and retros. Contains approx. 180 000 problems.(Some of them mine :))

(2) Meson database http://www.bstephen.me.uk/access_meson.html maintained by Brian Stephenson. It contains approx. 134 000 problems. Many of them orthodox 2- or 3-movers. Constantly updated.

(3) Yet another chess problem database (yacpdb) http://dt.dewia.com/yacpdb/#SearchHelp is the newest of all three. It has 286 590 problems currently and is a kind of wiki as well.

Of course all three have different seach facilities. So there a learning curve to use them. Only the last (yacpdb) has facilities for direct FEN searching, which I used to track down Jeroen's enquiry.

On the subject of chess engines and problem solving there are quite a bit to discuss, but let's leave that for the other time. Did you know that Rybka (1 to 4) does not consider bishop underpromotion at all? Not in a game nor in a problem.


Top
 Profile  
 
User avatar  Offline
Site Admin
 
Joined: Thu Sep 04, 2003 12:42 am
Posts: 1430
Location: Utrecht, The Netherlands
 Post subject: Re: Mate in two?
PostPosted: Sat May 29, 2010 8:17 pm 
mrmip wrote:
Hello Jeroen,

It may come as a surprise for you, but the Z comes from the composer's first (possibly second?) name. We have Mach,Zdenek and Mach,Julius Zdenek who appear to be the same early Czech (Bohemian really) composer. More interestingly the minature twomover appeared in "Nove Parizske mody"-publication along with several of it's variants - probably right alongside with the the add for latest Parisian lingerie. :). It appears that this publication was very popular among the Czech problemists around 1900. Cross-dressers all of them, I say.

The threemover You asked about is really composed by Zdenek Mach and appeared first in "Das Schachfreund" in 1896 winning an honorary mention. It is a crafty composition, where the black rook cannot do much to prevent the mate. I liked the variation 1...f4 best.

Just for the record I know of at least three freely available, searchable problem databases in the net, where you can possibly find the name of a composer if you know the position (and the otherway around). These are

(1) Problem data base (PDB) http://www.softdecc.com/pdb/index.pdb maintained by Gerd Wilts. This is great especially for helpmates and retros. Contains approx. 180 000 problems.(Some of them mine :))

(2) Meson database http://www.bstephen.me.uk/access_meson.html maintained by Brian Stephenson. It contains approx. 134 000 problems. Many of them orthodox 2- or 3-movers. Constantly updated.

(3) Yet another chess problem database (yacpdb) http://dt.dewia.com/yacpdb/#SearchHelp is the newest of all three. It has 286 590 problems currently and is a kind of wiki as well.

Of course all three have different seach facilities. So there a learning curve to use them. Only the last (yacpdb) has facilities for direct FEN searching, which I used to track down Jeroen's enquiry.

On the subject of chess engines and problem solving there are quite a bit to discuss, but let's leave that for the other time. Did you know that Rybka (1 to 4) does not consider bishop underpromotion at all? Not in a game nor in a problem.




These are some valuable resources, sir! Those cross dresser do know their chess problems...... :)

The ascendancy of tablebases and mate searchers and the like have led to simpler programming but to the loss of some capabilities in the process as well. More often than I like I arrive at an endgame where I am sure it's a draw, despite the material advantage the chess engine gives me. I created a small database with a few of those positions and have seen some chess engines getting worse at solving them throughout the years. Shredder is often a good choice to analyze an endgame position with.

An example is Fritz 12. Let it crunch on the position and it won't find the correct move. Rybka finds it though.

On the specific subject of bishop promotion - to be honest I think there are very few positions where a specific underpromotion to bishop is in order. Most stalemate threats can be circumvented by rook underpromotions; but a chess engine should be able to find any underpromotion if it's necessary. You can find all the tactical shenanigans you have to find, but you really should find the last one giving you the victory - else it's a big "alas, it's all for naught"....


Top
 Profile  
 
User avatar  Offline
Pawn
 
Joined: Fri Dec 07, 2007 3:34 am
Posts: 12
Location: Columbus, Ohio
 Post subject: Re: Mate in two?
PostPosted: Tue Jun 08, 2010 3:13 am 
Yes, 1. Rh8 is a nice move. But in terms of solving for "mate in 2" it's still not guaranteed.

1. Rh8 presumes that Black's next move would be to capture one of the rooks (at h8 or h6). If 1...KxRh8, then 2.Qf8++ {the Knight is pinned by Rook at h6}. If 1....KxRh6, then 2. Qg5++ {the Knight is pinned by Rook at h8}.

But what if Black decides not to capture either Rook after 1. Rh8 and goes...
1....Kf7

Then how does White mate on the next move?!!!

So, as far as I can tell, it's still not a "mate in 2" !!
Any thoughts?


Top
 Profile  
 
User avatar  Offline
Moderator
 
Joined: Thu Dec 09, 2004 9:20 pm
Posts: 1077
Location: Wales, UK
 Post subject: Re: Mate in two?
PostPosted: Tue Jun 08, 2010 6:01 am 
2. Qa7 would seem to do the trick!


Top
 Profile  
 
User avatar  Offline
Site Admin
 
Joined: Thu Sep 04, 2003 12:42 am
Posts: 1430
Location: Utrecht, The Netherlands
 Post subject: Re: Mate in two?
PostPosted: Tue Jun 08, 2010 9:23 pm 
ColumbusMark wrote:
Yes, 1. Rh8 is a nice move. But in terms of solving for "mate in 2" it's still not guaranteed.

1. Rh8 presumes that Black's next move would be to capture one of the rooks (at h8 or h6). If 1...KxRh8, then 2.Qf8++ {the Knight is pinned by Rook at h6}. If 1....KxRh6, then 2. Qg5++ {the Knight is pinned by Rook at h8}.

But what if Black decides not to capture either Rook after 1. Rh8 and goes...
1....Kf7

Then how does White mate on the next move?!!!

So, as far as I can tell, it's still not a "mate in 2" !!
Any thoughts?



These are all possible combinations:
1. Rh8 Kxh8 2. Qf8#
(1... Kxh6 2. Qg5#)
(1... Kf7 2. Qa7#)
(1... Ng5 2. Qf8#)
(1... Nf6 2. Qf8#)
(1... Nf8 2. Qxf8#)


Top
 Profile  
 
Display posts from previous:  Sort by  
This topic is locked, you cannot edit posts or make further replies.  [ 9 posts ] 

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 193 on Thu Jun 28, 2007 1:40 pm

Users browsing this forum: No registered users and 1 guest





cron

ChessCentral - The Leader in Cutting-Edge Chess * Buy Fritz 12 * Buy Rybka 4 * Buy Fritz Powerbook DVD


Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group

Style based on Andreas08 by Andreas Viklund and created by Elizabeth Shulman, Stop Animal Rights, Dog Training by corgipower