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Subject: Re: How did Alen Turning's program work?

Author: Pete Galati

Date: 10:47:20 04/21/00

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On April 21, 2000 at 12:17:51, Robert Pope wrote:

>On April 21, 2000 at 07:43:51, Alessandro Scotti wrote:
>
>>On April 20, 2000 at 19:51:02, Pete Galati wrote:
>>
>>>I've seen Alen Turning's Chess program that only existed on paper mentioned a
>>>few times, but I don't think I've seen any mention of how it actually worked.
>>>
>>>Has his program ever been published?
>>
>>I'm very interested in this subject of reviving old programs. After a little
>>search I was able to dig out the original papers by Kotok and Bloom (in the form
>>of bitmap scanned pages!) but it seems I'm missing a couple of additional pages
>>which contained moves from actual games, a very useful thing for testing. If
>>there's enough information available it could be possible to write a program
>>that plays (more or less) the same even if the original code is not available.
>>
>>Sorry if I haven't answered your question... I'm looking for info too!
>
>The Turing's article in "Faster than Thought" is also reprinted in David Levy's
>"Computer Chess Compendium".  I was planning to recode some of the early
>evaluation functions as options in my own program, but I haven't had a chance to
>do any work on it recently.  It is similar to other current bare-bones programs,
>though his selection of moves to look at in quiescence is a little unique.
>
>Here is a quick synopsis:
>P=1, N=3, B=3.5, R=5, Q=10, checkmate=1000
>
>Search: 2 ply exhaustive, then quiescence.
>
>Quiescence:
>All recaptures, all en prise captures, all checkmating moves, all captures where
>value(attacker)<value(captured piece).
>
>Evaluation=W/B, white's piece totals over black's.
>
>If there is a tie, look at Position-play value for white pieces and black king,
>consisting of:
>a) +sqrt(true legal mobility of each N,R,B,Q), capture moves count double
>b) +1.0 for non-queens that are defended, +1.5 if twice-defended
>c) +sqrt(t.l.m. of king, excluding castling)
>d) -sqrt(mobility of queen if it were on king's square)
>e) +1.0 if moves do not destroy castling possibility
>   +1.0 if castling is possible on next move
>   +1.0 if castle this move
>f) +0.2 per rank advanced per pawn
>g) +0.3 per pawn defended by a non-pawn.
>h) +1.0 for threatening checkmate of black king (??)
>i) +0.5 for checking black king
>
>Square roots are rounded to nearest tenth.
>
>Hopefully this is all right -- I am typing by hand and interpreting what he
>says, which is sometimes ambiguous.
>
>Rob

Thanks, I made a copy of that.  I've got my local library getting me a copy of
"Alan Turing, The Enigma" sometime next week, and Barnes & Nobel has ordered a
copy of "Machines and Thoughts", but they know nothing about Turing's "Faster
Than Thought".  Maybe one of them will have good notes about Turochess.

At the moment Turing's papers don't seem to be online yet, hopefully soon, see
this page: http://www.turing.org.uk/sources/archive.html  who says:

" Part of this collection of papers has now been scanned or photographed to a
  high quality and should be available on-line in May 2000 as the Digital
  Turing Archive."

lets all hold our breath and see if we turn blue.  But that's just next month,
so I'm hoping it's true.

Pete



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