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

Author: Robert Hyatt

Date: 15:21:06 10/17/02

Go up one level in this thread


On October 17, 2002 at 11:34:35, Uri Blass wrote:

>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.

I don't disagree, although I know how the hardware was implemented, and it isn't
nearly
so clean to try to be asymmetric based on search depth.  This is basically a
finite state machine
and it makes far more sense for everything to be done the same way, from ply 1
to ply N,
inside the hardware...


>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.

Sure.  That is why the question needs to be posed properly rather than the vague
questions
that were asked the last time...


>>
>>
>>
>>>
>>>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.

But "up to 6" then means "no more than 6 plies of extensions."  I _know_ that
they
allowed two plies of extensions for every 2 plies of search, which means that a
2
ply search could go to 40+ plies if needed...

The "up to 6" doesn't fit there at all...


>
>
>>
>>
>>
>>
>>>>
>>>>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.

Then vincent's 4(5) can't possibly be right either.  Hsu _clearly_ said 4 means
4
plies of "brute-force" search.  Whatever the hardware does, it does at _every_
ply,
so the 4(5) explanation you are proposing just doesn't fit...


>
>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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