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Subject: Re: Crafty and Cray Blitz Questions to Prof. Hyatt

Author: Robert Hyatt

Date: 19:31:33 10/09/00

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On October 09, 2000 at 13:59:55, Aaron Tay wrote:

>On October 09, 2000 at 13:38:37, Robert Hyatt wrote:
>
>>On October 09, 2000 at 12:46:27, Joshua Lee wrote:
>>
>>>Since you can't compare them by playing each other what about comparing
>>>printouts? Are there any printouts that have NPS Depth line etc. If i had this i
>>>would attempt. I did look at a game against Chiptest where CB had 14 Ne6 but
>>>played Na4<-- not the losing move but not as good as Ne6 CB get's a queen Vs 3
>>>minor pieces which is not easy but it would be alot better than the situation
>>>before if CB could keep his queen on and exchange rooks it makes it easier. As
>>>Black's only chances would be to obtain a new queen not likely. So the outcome
>>>is probably a draw but this is just my guess.  To see this move for Crafty would
>>>be over 14Ply on my 800Mhz Athlon just to give you some idea. If you can
>>>elaborate on CB's earlier versions and how they played maybe this will answer my
>>>questions and help you to improve on crafty.
>>>
>>>
>>>Sometimes it's all about asking the right question.
>>>
>>>thank you
>>
>>
>>Actually I did this a couple of years ago and posted the results in r.g.c.c I
>>believe.  I took a couple of the world championship 1986 games (the wc won by
>>CB for the second time in a row) and had Crafty 'annotate' the games.  It was
>>uncanny how they agreed tactically.  Of course, 1986 CB was doing maybe 100-200K
>>nodes per second max, so crafty had a big edge in speed.  But it found _zero_
>>tactical mistakes by CB.
>>
>>I analyzed the games partly in a discussion with Chris Whittington where he
>>was into the usual mode of criticizing Cray Blitz for any reason.  He picked on
>>one particular move as looking foolish.  Someone else pointed out that CSTal
>>played the _same_ move, as it was tactically forced to avoid losing a pawn,
>>but of course that didn't make any difference.  I became interested in how
>>Crafty would compare.  I gave crafty more time than CB had, using faster
>>hardware than CB had (1986 hardware for CB, remember), and it couldn't find
>>any move it would label as a mistake or oversight.
>>
>>CB was tactically very strong.  In most positional cases the two programs were
>>in agreement as well, which is not surprising since I wrote both.
>>
>>The main advantage CB might have had back then was far faster hardware than
>>anything I might run Crafty on in 1986.  Of course Crafty would have run on a
>>Cray back then, but it would have been far slower as Crafty is not vectorized
>>while CB was.  I suspect there is not a lot of difference in the two programs
>>today.  CB might have a tactical edge due to singular extensions and a bit of
>>selectiveness near the leaf positions, while crafty probably has more >positional (particularly endgame) knowledge (excepting king safety where CB >was clearly better).
>
>Sorry to interrupt, but does that mean that as of today you wouldn't bet on
>Crafty running on your current hardware to beat CB (the lastest/last version)?
>
>So when do you anticipate will Crafty overtake CB? In 5 years time, when everone
>is using better hardware?


You will have to rephrase your question a bit.  But to help, if you meant
"can crafty on the quad xeon play with Cray Blitz on the T90?" the answer
is _NO_.  CB on the T90 runs at around 7M nodes per second, about 7X faster
than the quad xeon.  I wouldn't want to play such a handicap match.

On the other hand, if you mean "Can Crafty, on the best box you can get today
play with CB on the T90?" the answer is yes.  I have some data from Tim Mann's
21264a machine which is about as fast as my quad xeon, but using a single cpu
at 667 mhz.  A 16 cpu machine would be faster than Cray Blitz.  And I would
expect it to win more than it would lose, although I think it would be pretty
close.



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