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Subject: Re: Q&A with Feng-Hsiung Hsu

Author: Uri Blass

Date: 08:34:35 10/17/02

Go up one level in this thread


On October 17, 2002 at 10:41:20, Robert Hyatt wrote:

>On October 17, 2002 at 06:13:26, Johan Melin wrote:
>
>>On October 16, 2002 at 23:35:10, Robert Hyatt wrote:
>>
>>>On October 15, 2002 at 14:01:35, Johan Melin wrote:
>>>
>>>>On October 14, 2002 at 07:34:16, Bas Hamstra wrote:
>>>>
>>>>>Bob, did you read the Hsu transcript posted here? It is pretty clear to me that
>>>>>Hsu himself says 12 ply fullwidth *total*. Case closed. Please read the complete
>>>>>transcript.
>>>>>
>>>>>Best regards,
>>>>>Bas.
>>>>
>>>>I agree. The transcript with Hsu is clear. But it would be out of character for
>>>>CCC if everybody just agreed with each other, there still has to be a fight ...
>>>>;)
>>>>
>>>>/Johan Melin
>>>
>>>
>>>Here is the relevant part of the transcript:
>>>
>>
>>There are other relevant parts? How about:
>>
>>----------------------------------
>>EeEk(* DM) kibitzes: kib question from ardee: Does "12(6)" mean 12
>>total ply or 12+6=18 total ply?  This has the been source of huge
>>arguments for years!
>>CrazyBird(DM) kibitzes: 12 total in terms of brute force. 6 is just
>>the max partition in hardware.
>>----------------------------------
>>
>>He sais 12 _total_. He also refers to 6 as "just", implying that it is less
>>important than the 12.
>
>
>No he clearly did _not_ say "12 total".  He said "12 plies of brute force".  He
>also
>said elsewhere that the _hardware_ does forward pruning.  So "12 plies of brute
>force"
>implies that is non-hardware...

It is not clear from it.

suppose the hardware never pruned in the first 3 plies in the hardware when the
hardware get depth 6.
Suppose also that the software sent the hardware only lines of at least 9 moves.
You can have 12 plies of brute force when 6 is the maximal depth in the
hardware.
>
>
>
>>
>>If somebody tells you that "the storage capacity of this harddrive is 20 GB, 5
>>GB is just the linux partition", then what is the storage capacity? 25 GB?
>
>No.  But nobody has said that.  they have said "20 gigabytes of space".
>The hardware has 5 gigabytes of buffer."  Does the thing have 20 gigs or
>25 gigs _now_???  From a speed perspective, it matters how that is done.
>
>
>>
>>----------------------------------
>>EeEk(* DM) kibitzes: question from parabola444:  You mentioned Deep
>>Blue searched about 12 plies brute force + extensions, which is
>>similar to what pc programs these days get on a fast pc - since Deep
>>Blue hardware was much faster, how come it didn't search significantly
>>deeper ?
>>CrazyBird(DM) kibitzes: to all the book readers, if you do like the
>>book, please tell your friends would might be interested. thanks.
>>CrazyBird(DM) kibitzes: replace would with who:).
>>CrazyBird(DM) kibitzes: we were using fairly extensive search
>>extensions, and the decision not to use null move pruning was an
>>deliberate one.
>>----------------------------------
>>
>>The interesting part here is not just what he says, but what he doesn't say. If
>>they search 18 plies nominal, he would have said so. Why would he hold back such
>>a statement? He indirectly agrees to searching only 12 plies.
>
>Again, Hsu tries to answer what he is asked, as briefly as possible.  The
>hardware does
>forward pruning.  They have _always_ given the "software depth" when they
>discuss
>this kind of number.  Whether he still is is up for debate, but I doubt he would
>suddenly
>change his terminology after using it for 15 years...
>
>
>
>
>>
>>
>>>-----------------------------------------------------------------------------------------------------------------------
>>>CrazyBird(DM) kibitzes: 12(6) means 12 plies of brute force (not
>>>counting the search extensions & quiescence).
>>>CrazyBird(DM) kibitzes: 6 means the maximum hardware search depth
>>>allowed.
>>>CrazyBird(DM) kibitzes: this means that the PV could be up to 6 plies
>>>deeper before quiescence.
>>>-----------------------------------------------------------------------------------------------------------------------
>>
>>Note that in the first line he states "not counting ..." but does not mention
>>any extra plies from hardware. Wouldn't 6 plies be more significant than
>>quiescence? So why doesn't he mention that it isn't included in the 12 plies?
>>
>
>What about the last sentence.  It seems to say exactly what you say is missing.
>
>"up to 6 plies deeper".

up to 6 plies deeper relative to the logfile.
I do not know if they did extensions in the hardware but even if I assume that
they did ply can include also extensions.

When people says that the program search 6 plies it includes extensions so it is
possible that when 6 plies are missing it includes extensions.


>
>
>
>
>>>
>>>OK, some questions:
>>>
>>>1.  If 12(6) means 12 plies total, with 6 done in hardware, how do you reconcile
>>>that
>>>_last_ sentence above (the PV could be up to 6 plies _deeper_ before
>>>quiescence).
>>>Deeper than what?  Only possible answer is deeper than 12 plies.
>>
>>He is talking about the PV. Their hardware return a score, but no PV. So
>>sometimes they didn't get a complete PV, and say "the pv COULD BE UP TO ...".
>
>
>
>That makes no sense.  They don't limit the 12 ply search to 6 plies of
>extensions
>total.    So he is not talking about search extensions.   Saying "the PV could
>be up
>to 6 plies deeper" is _obviously_ not a reference to the missing pv from the
>hardware
>for many reasons.  First, if the hardware is searching 6 plies, the PV would not
>be
>"up to 6 plies more" it would be "at _least_ 6 plies more because of the
>hardware search
>extensions + qsearch".


>
>
>>
>>>
>>>2.  If 12(6) means 12 plies total, with 6 in hardware, what does 4(5) mean?  4
>>>plies total
>>
>>Uri Blass suggests aggresive extensions that increase the remaining depth.
>
>Again, that makes no sense in this context.  It would _instantly_ have to resort
>to a
>hardware-chip only search if the above means 4 plies brute force, 5 plies of
>that done
>by hardware.

I do not see the problem.

It is possible that deeper blue extended 4 plies for the first 3 plies so the
first 3 plies were done in the software and the last 5 plies were done in the
hardware.

plies is used in a different meaning here but the meaning is clear.
last 5 plies means depth 5 for the hardware and first 3 plies means first 3
moves.

Uri



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