Author: Jeremiah Penery
Date: 17:32:45 10/19/02
Go up one level in this thread
On October 19, 2002 at 19:50:02, Uri Blass wrote: >On October 19, 2002 at 19:29:15, Jeremiah Penery wrote: > >>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? > >If the software searched 7 plies then it told the hardware to search 5 plies and >not 6 plies >see the following: > >"2.Does 12 means that the depth of the software in deeper blue was less >than 12 plies(12-x when x is the depth of the hardware that is not constant)? >CrazyBird: yes, the software "brute force" depth is always less." > >Hsu agreed that 12 means 12-x in the software when x is the depth of the >hardware. It seems like in 12(6), software depth is anywhere between 6 and 11, and the hardware makes up the rest of the 12. It makes sense, though it is a little strange, and he could (should) have very easily made it clear before. But I still don't know how to make sense of 4(5), when Hsu says it was impossible, yet it happened in most of their searches. If the number is simply wrong, then what assurance is there that all other the other depth numbers are correct? Hsu could have just said "12 is software+hardware depth", but instead he says "12 in terms of brute force" before, and then in response to your question he said "the *software* 'brute force' depth is always less." Why does he use the term brute force in both of those statements, which gives the impression that he uses the term to describe only the software search? Of course, if his comments today were correct, then the hardware should also be counted in the 'brute force' depth, but he doesn't make it very clear in his statements.
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