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Subject: Re: Never Say "Impossible"

Author: Robert Hyatt

Date: 19:01:31 05/09/01

Go up one level in this thread


On May 09, 2001 at 19:20:18, Uri Blass wrote:

>On May 09, 2001 at 18:41:43, Robert Hyatt wrote:
>
>>On May 09, 2001 at 13:33:21, Uri Blass wrote:
>>
>>>
>>>The rules of chess say that the if a game takes more than 9999 half moves both
>>>sides can ask for a draw by the 50 move rule.
>>>
>>>If you do not assume that both opponents are stupid in your calculation then it
>>>is clear that one of them will ask for the draw so you can assume for practical
>>>purpose that it is a draw.
>>
>>
>>Suppose it is a game, for "winner takes all" where if it is drawn, nobody
>>gets a cent?  Will you claim the 50-move draw there or will you keep trying
>>to win the pot of gold?
>>
>>Then you see why I say that unless someone proves that chess is won for white
>>or black, which is not going to happen for a few thousand centuries, then I
>>will keep playing.  Until the end of time if needed, hoping for my opponent to
>>make a mistake...
>>
>>
>>>
>>>I can prove for a bigger constant that there is not.
>>>The shortest mate is of less than 10^100 plies because every game of 10^100
>>>plies include repetitions and if there is a mate there is a shorter mate with no
>>>repetitions.
>>>
>>>Uri
>>
>>
>>That doesn't make the length of all possible games finite however.
>
>It is totally irrelevant.
>The point is that even without the 50 move rule after enough plies searching
>deeper is not going to give better results.
>
>If you find a forced mate for one of the sides it is clear that searching deeper
>is not going to help.
>
>If you do not find a forced mate for one side then it is clear that the position
>is drawn and searching deeper is not going to help(programs do not assume that
>the opponent will do a mistake in their search).
>
>Uri


Please prove that KQQQ vs KQQQ is drawn or won for each case.  Note that we
declare the 50-move rule is not in use.  How do you decide when to declare a
position drawn?  No captures in 50 moves?  I'll be happy to show you a 5 piece
position where a forced mate happens _well_ beyond the 50 move rule.  So how
do you stop?

It isn't necessary that my opponent "do a mistake".  It is just necessary that
I search deeply enough to find the forced win that just happens to be beyond
50 moves.  Or beyond 500 moves.  Or beyond 5000 moves.  If you can prove that
for a simple 8 piece ending, then we go to nine and then ten.  Pretty soon we
are into some _huge_ trees.  I think you will find the KQQQ vs KQQQ is more
than enough however, to make this point.  We know that for 5 piece endings we
have mates beyond 100 moves.  For 6 we don't know the max yet, but we do know
it is > 5 piece max.  There are some known 200 move mates in 6 piece endings
with no captures for way over a hundred moves.  What do you think might happen
by the time we attempt 32 man files?  billions of moves before a forced mate?



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