Author: Vincent Diepeveen
Date: 16:56:15 10/19/02
Go up one level in this thread
On October 19, 2002 at 19:29:15, Jeremiah Penery wrote:
all your questions are answerred very easily by a few lines
in software hsu could have had. Of course ignoring the
single bound way of searching.
Important thing is the redividing all the moves of a ply
when a hardware processor gets a timeout (search takes
too long in hardware, well what you guess with near to
minimax search done to it).
int search(int depthleft) {
if( depthleft <= 6-ENDGAMEPHASE ) {
time t1 = GetClock();
score = SearchInHardware(position,6-ENDGAMEPHASE);
result = SetEventCheckForTimeOut(t1+TIMEOUT);
if( result == TIMEOUT ) {
for( all moves ) {
score = SearchInHardware(position,6-ENDGAMePHASE-1);
}
}
return score;
}
else {
..
search(depthleft-1);
}
}
>On October 19, 2002 at 17:03:51, Dave Gomboc wrote:
>
>>On October 19, 2002 at 14:45:19, Steve Lim wrote:
>>
>>>SJLIM: Alot of programmers on CCC have asked me to ask you this.. for
>>>clarification..
>>>SJLIM: Please explain search depths for the notations 4(5) and clarify earlier
>>>comments about 12(6). This may include indicating what is "normal full width"
>>>searching, extensions, quiesence search, or other types of searching DB2
>>>utilized, and which was done in software versus in the hardware chess chips.
>>>SJLIM: Also, what types of pruning were used. This topic has generated enourmous
>>>discussion on CCC.
>>>CrazyBird: 4(5)means the same thing. 5-ply maximum hardware depth, although it
>>>is obviously impossible in this case.
>>>CrazyBird: since the brute force depth is 4.
>>>CrazyBird: i can't really go into the details of the hardware pruning. it is
>>>related to method of analogy pruning, or rather a basterized form of it.
>>>CrazyBird: limitation in the contract with ibm.
>>>SJLIM: Can this be answered? - Does 12(6) mean the 6 is included _in_ the 12, or
>>>in addition to the 12?
>>>CrazyBird: 6 is part of 12, but the hardware can search less than 6, that is the
>>>software horizon may be more than 6 plies.
>>>CrazyBird: and of course, the selective depth can be arbitrarily deep, well, no
>>>more than 8 times brute force.
>>>CrazyBird: argh, the q search. it is in hardware. both sides are allowed checks
>>>in quiescence search. max is 8, i think.
>>
>>Clearly, Vincent's interpretation is supported here.
>>
>>I'm still sure they were searching much deeper than 12 ply in important lines
>>though!
>
>Strange that he said 4(5) is an impossible case, when at least half of their
>searches had that depth reported. Also, I'm not sure how, if the second number
>is a maximum depth, that it could be included in the first number, when the
>second number is variable (not to mention that the second number is often bigger
>than the first). It implies that the first number (software depth, not counting
>extensions/pruning) is variable also (which Hsu said), but I'm not sure how that
>would work.
>
>>>CrazyBird: 6 is part of 12, but the hardware can search less than 6, that is >>the software horizon may be more than 6 plies.
>
>Say the software searched 7 plies (or more) - how do we know that the hardware
>didn't also search 6 plies beyond that (we just know it didn't search MORE than
>6 plies).
>
>Maybe I'm being a bit obtuse, can anyone try to explain this to me?
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.