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Subject: Re: What do programmers think about a chess algorithm??

Author: J. Wesley Cleveland

Date: 09:47:20 12/12/02

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On December 11, 2002 at 16:46:21, Dann Corbit wrote:

>On December 11, 2002 at 15:04:41, J. Wesley Cleveland wrote:
>
>>On December 10, 2002 at 18:28:08, Dann Corbit wrote:
>>
>>>On December 10, 2002 at 18:24:20, Uri Blass wrote:
>>>
>>>>On December 10, 2002 at 18:12:53, Dann Corbit wrote:
>>>>
>>>>>On December 10, 2002 at 17:55:51, Dann Corbit wrote:
>>>>>
>>>>>>On December 10, 2002 at 17:51:40, Ingo Lindam wrote:
>>>>>>
>>>>>>>On December 10, 2002 at 17:30:47, Dann Corbit wrote:
>>>>>>>
>>>>>>>>On December 10, 2002 at 13:42:36, Bernardo Wesler wrote:
>>>>>>>>[snip]
>>>>>>>>>THE ALGORITHM. A MATHEMATICAL FORMULA THAT , FOR EXAMPLE, ASSURE YOU THAT IF YOU
>>>>>>>>>DO THE FIRST MOVE YOU ALWAYS WIN.
>>>>>>>>>I MEAN TO THINK ABOUT DISCOVERING A CHESS ALGORITHM IS AN UTHOPY?
>>>>>>>>
>>>>>>>>Provably impossible on current hardware and software systems.
>>>>>>>>Maybe in 100 years the game will be formally solved.  Not in the near futre.
>>>>>>>
>>>>>>>provably impossible on current hardware...?
>>>>>>>are you sure?
>>>>>>
>>>>>>Absolutely sure.
>>>>>>
>>>>>>To solve chess you must store at least the square root of nodes of the solution
>>>>>>tree.  Considering the half move clock and castle rights, it easily exhausts any
>>>>>>possibility of solution.
>>>>>>
>>>>>>>without assuming anything about the kind of solution?
>>>>>>
>>>>>>No assumptions are necessary.  We pick an adversary in the tree.  It's just like
>>>>>>how you would prove a sort works in O(f(n)).
>>>>>>
>>>>>>>atleast you are assuming the use of hardware...
>>>>>>>(an assumtion I could live with because I wouldn't bet on find the solution
>>>>>>>faster by using just a pencil and a sheet of paper :-))
>>>>>>
>>>>>>I am assuming that if you turned the universe into silicon chips and devoted
>>>>>>half of them to CPU's and the other half to memory storage that all the stars
>>>>>>will go out before you find the answer.
>>>>>>
>>>>>>>me would like to see the proof for 'provably impossible' as much as I would like
>>>>>>>to see the solution for chess
>>>>>
>>>>>10^48 formations * 100 states for half-move clock * 4 bits for castle state.
>>>>>sqrt(1.5e+51) = 38729833462074168851792654 [64 moles of positions ;-)]
>>>>
>>>>Most of the legal positions are irrelvant for solving chess because they can
>>>>happen only after both sides play illogical moves.
>>>
>>>They are still fully relevant.  You might throw away your queen and both rooks
>>>and still win (in fact, it has been done).
>>>
>>>>I do not know the number of legal positions but I know no proof that there are
>>>>more than 10^40 and I know no proof that the relevant legal positions to solve
>>>>chess are more than 10^20
>>>>
>>>>positions like 1.a4 a6 may be irrelevant to solve chess if you find that 1.a4 is
>>>>losing against 1...e5 when 1.e4 is not losing.
>>>
>>>In order to prove that they are irrelevant, you will have to solve the tree.  In
>>>order to solve the tree you will have to compute and store it.
>>
>>Except he does not have to prove that they are irrelevant, you have to prove
>>they are relevant.
>
>If he has not disproven them, then he has not demonstrated his point of a
>suggested outcome.  Either I am not communicating clearly or you do not
>understand what I have said.

You are the one that said you could prove that chess was not currently solvable,
which means others can speculate and you have to prove them wrong.

>
>>>>in that case knowing the theoretic result after 1.a4 a6 is going to change
>>>>nothing.
>>>>
>>>>Tree is only one way to prove things.
>>>>
>>>>It is possible to prove that KQ vs K without the 50 move rule win in n*n chess
>>>>board for every dimension n.
>>>
>>>Believe it or not, you form a tree to solve it.  You might have an alternate
>>>formulation, but a tree solution will be perfectly equivalent and optimal.
>>
>>You are wrong here. You can prove by induction that KQ vs K is mate on a
>>chessbord that is e.g. 10^17 by 10^17, while the tree is roughly the same size
>>as the tree of chess.
>
>How many moves will the induction contain?
>
>The same as the tree.

The proof takes only a few steps. Define king confined in a rectangle n,m as
queen on square n+1,m+1, king in the rectangle not adjacent to the queen, and
opposing king outside the rectangle n+1,m+1. Prove if the king is confined in a
rectangle of 3,1 or 3,2, it is checkmate. Prove if the king is confined in a
rectangle of n,1, you can force it to be confined in a rectangle of n-1,1. Prove
if the king is confined in a rectangle of n,m, you can force it to be confined
in a rectangle of n-1,m or n,m-1. Prove that you can confine the king in a
rectangle. QED.



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