Reply
 
LinkBack Thread Tools Display Modes
  #1   Report Post  
Old August 27th 13, 02:56 PM posted to rec.games.chess.analysis
abc abc is offline
external usenet poster
 
First recorded activity by ChessBanter: Aug 2013
Posts: 5
Default What's the biggest material advantage that cannot mate?


Actually, I'll repost here since the question went unnoticed in
the other group for several months:

Chris F.A. Johnson wrote:
On 2012-08-26, abc wrote:

What's the biggest material advantage that cannot mate against a

lone king?

Two knights and a king cannot *force* mate against a lone king,
though a mate is possible.

Otherwise, K+B or K+N cannot mate a lone king.


Let's see. The two knights is roughly 600 centipawns, right?
And one Knight or one Bishop is 300 centipawns.

That's a good start, but it is far from the biggest.

And apologies for not being precise. I'll rephrase
the question slightly:

What is the biggest material advantage that can
_never force_ a mate against a lone King, regardless
of position, ie. there are NO positions that can be
set up with that material from which mate can be
forced?

And a second question:

What is the biggest material advantage where a
mate is not possible against a lone King, even
with the cooperation of the opponent, ie. there
are NO positions that can be set up with that
material that are mate or from which mate can
be reached by any sequence of legal moves?

Incidentally, the answer to both questions is
exactly the same.

Got you all thinking now, have I? Or not?

Those of you who knew it from before, please refrain
and don't spoil the fun for the rest of us.
abc
  #2   Report Post  
Old September 6th 13, 01:02 PM posted to rec.games.chess.analysis
abc abc is offline
external usenet poster
 
First recorded activity by ChessBanter: Sep 2010
Posts: 14
Default What's the biggest material advantage that cannot mate?

abc wrote:

Actually, I'll repost here since the question went unnoticed in
the other group for several months:

Chris F.A. Johnson wrote:
On 2012-08-26, abc wrote:

What's the biggest material advantage that cannot mate against a

lone king?

Two knights and a king cannot *force* mate against a lone king,
though a mate is possible.

Otherwise, K+B or K+N cannot mate a lone king.


Let's see. The two knights is roughly 600 centipawns, right?
And one Knight or one Bishop is 300 centipawns.

That's a good start, but it is far from the biggest.

And apologies for not being precise. I'll rephrase
the question slightly:

What is the biggest material advantage that can
_never force_ a mate against a lone King, regardless
of position, ie. there are NO positions that can be
set up with that material from which mate can be
forced?

And a second question:

What is the biggest material advantage where a
mate is not possible against a lone King, even
with the cooperation of the opponent, ie. there
are NO positions that can be set up with that
material that are mate or from which mate can
be reached by any sequence of legal moves?

Incidentally, the answer to both questions is
exactly the same.

Got you all thinking now, have I? Or not?

Those of you who knew it from before, please refrain
and don't spoil the fun for the rest of us.
abc


Oh well, either this was such an old well-known problem
that no-one can be bothered to answer, OR it might be
that nobody actually knows the answer. I'm not sure which.
abc

  #3   Report Post  
Old September 6th 13, 02:08 PM posted to rec.games.chess.analysis
external usenet poster
 
First recorded activity by ChessBanter: Dec 2008
Posts: 116
Default What's the biggest material advantage that cannot mate?

On 06/09/13 13:02, abc wrote:
What is the biggest material advantage [...]
And a second question: [...]
Incidentally, the answer to both questions is
exactly the same.


If the intended answer is anything other than B or N
[eg, BBBBBBBBB or even BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB],
then I think you haven't specified the problem adequately.

Those of you who knew it from before, please refrain
and don't spoil the fun for the rest of us.

Oh well, [...].


It's a bit mean to ask us to refrain and then grumble
when no-one replies.

--
Andy Walker,
Nottingham.
  #4   Report Post  
Old September 6th 13, 02:49 PM posted to rec.games.chess.analysis
external usenet poster
 
First recorded activity by ChessBanter: Jul 2006
Posts: 1,015
Default What's the biggest material advantage that cannot mate?

On 06/09/2013 14:08, Andy Walker wrote:
On 06/09/13 13:02, abc wrote:
What is the biggest material advantage [...]
And a second question: [...]
Incidentally, the answer to both questions is
exactly the same.


If the intended answer is anything other than B or N
[eg, BBBBBBBBB or even BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB],
then I think you haven't specified the problem adequately.


KBBBBBBBBBk (K+9B vs k) might be doable with help from black. You would
have to agree in advance that he never takes any of your pawns and also
facilitates every promotion to be a black (or white) squared bishop.

Those of you who knew it from before, please refrain
and don't spoil the fun for the rest of us.

Oh well, [...].


It's a bit mean to ask us to refrain and then grumble
when no-one replies.


If it doesn't have to arise from a game then 32 same colour square
bishops seems be the maximum material advantage unable to give mate.

These extremal positions tend to break some chess engines.

I agree the OP posed the question poorly and asked anyone who already
knew the answer not to reply. These groups are low traffic these days

--
Regards,
Martin Brown
  #5   Report Post  
Old September 6th 13, 07:37 PM posted to rec.games.chess.analysis
external usenet poster
 
First recorded activity by ChessBanter: Dec 2008
Posts: 116
Default What's the biggest material advantage that cannot mate?

On 06/09/13 14:49, Martin Brown wrote:
On 06/09/2013 14:08, Andy Walker wrote:
On 06/09/13 13:02, abc wrote:
What is the biggest material advantage [...]
And a second question: [...]
Incidentally, the answer to both questions is
exactly the same.

If the intended answer is anything other than B or N
[eg, BBBBBBBBB or even BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB],
then I think you haven't specified the problem adequately.

KBBBBBBBBBk (K+9B vs k) might be doable with help from black.
You would have to agree in advance that he never takes any of
your pawns and also facilitates every promotion to be a black
(or white) squared bishop. [...]


Yes, but that answers a quite different question from
the one the OP asked. If you have 9B's, then it's easy to set
up a position where the B's *can* mate; the material is a B,
not a B that must be placed on a black square [otherwise, we
could equally impose conditions on where any other piece could
be placed], If you just want to find *a* position where White
cannot *force* a win despite a large material advantage, even
without stalemate being an issue, then it's easy; eg

NQBBK1k1; QQQRP3; PRPP3N;1P6;32.

There are any number of similar positions where White cannot
win even with Black's help, because of stalemate.

--
Andy Walker,
Nottingham.


  #6   Report Post  
Old September 11th 13, 08:39 AM posted to rec.games.chess.analysis
abc abc is offline
external usenet poster
 
First recorded activity by ChessBanter: Sep 2010
Posts: 14
Default What's the biggest material advantage that cannot mate?

Andy Walker wrote:
On 06/09/13 13:02, abc wrote:
What is the biggest material advantage [...]
And a second question: [...]
Incidentally, the answer to both questions is
exactly the same.


If the intended answer is anything other than B or N
[eg, BBBBBBBBB or even BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB],
then I think you haven't specified the problem adequately.


Yes, 9 light-squared B against a lone king was the answer,
or 9 dark-squared B, making a 2700 centipawn material advantage.

I don't know about inadequate, but it could be specified
more completely by including a proviso that light-squared and
dark-squared B's be considered different pieces for the
purposes of the exercise, only that would have given the
game away and spoiled the fun entirely.

Those of you who knew it from before, please refrain
and don't spoil the fun for the rest of us.

Oh well, [...].


It's a bit mean to ask us to refrain and then grumble
when no-one replies.


You just have to live with that I'm afraid. The intention
was to drum up some activity and apparently it worked.
abc
Reply
Thread Tools
Display Modes

Posting Rules

Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
This news group ChessFire rec.games.chess.misc (Chess General) 26 March 23rd 12 04:52 PM
Video of the longest win of a queen over two horses Tantale rec.games.chess.analysis (Chess Analysis) 23 November 9th 08 07:15 PM
Sanny: Do you want more test positions? Guest[_3_] rec.games.chess.computer (Computer Chess) 7 September 2nd 08 11:26 PM
Which side would have an advantage: Pieces following Near Chess ornormal chess rules? Rich Hutnik[_2_] rec.games.chess.misc (Chess General) 8 April 24th 08 10:18 PM
tablebase for R+2N vs. R Jud McCranie rec.games.chess.computer (Computer Chess) 16 June 18th 06 03:01 AM


All times are GMT +1. The time now is 10:37 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 ChessBanter.
The comments are property of their posters.
 

About Us

"It's about Chess"

 

Copyright © 2017