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Subject: Re: Behind Deep Blue: 3rd print with new Hsu afterword

Author: Vincent Diepeveen

Date: 01:19:21 05/07/04

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On May 07, 2004 at 01:03:20, Jouni Uski wrote:

>Has You looked for that afterword? There is very short comment to Kasparov
>vs. Junior and Kramnik vs. Fritz. Hsu still claims DB was superior to
>Fritz/Junior in tactics! Really?
>
>Jouni

Let me quote Bruce Moreland: "i would love to have a shot at deep blue in blitz,
i tactically will destroy it".

This was with Ferret at a 4x 400Mhz PII machine.

I agree with Bruce.

We must be realistic. Deep Blue needed 3 minutes to get to 10 ply in openings
positions. In endgames it finished 12 ply a lot. Most middlegame positions
however it searched 10 - 11 ply.

On average they claimed a search depth of 12.2 ply but this is not iterative
depth but 'observed' depth. So the singular extension depth added to it (not
qsearch i guess).

10 ply with a singular extensions and threat extensions and mate extensions is
in theory tactical very strong. Certainly for 1997 standards.

However in hardware they cannot do any dangerous extension. Not only Hsu
explicitly mentions it, also Chrilly has done very clear statements that
hardware search is *that* inefficient that he had to forward prune in hardware
in a very primitive way. Same for Deep Blue. In its 4 ply of hardware search it
forward pruned, and *had* to of course. Both cannot use any dangerous extensions
in hardware search. Deep Blue triggers the last one at 4 ply depth left.

This where software products pick up incredible tactics last few plies. They see
just near to shit last few plies.

So you can extend a lot in mainsearch, but 10 ply - 4 = 6 ply. So within 6 ply,
it should see everything then.

Let's be clear, this in 2004 is not a realistic scenario. Hsu still lives in the
80s. He did live there in 1997 still. His machine didn't even use nullmove which
by 1995 had been clearly proven for every idiot on the planet as the way to go.

Frans Morsch *publicly* did statements about recursive nullmove. During dinner
every programmer has heard it, i'm sure of it.

What Hsu writes is utter nonsense.




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