Author: Uri Blass
Date: 09:09:25 10/14/02
Go up one level in this thread
On October 14, 2002 at 10:06:39, James Swafford wrote: >On October 14, 2002 at 09:44:06, Vincent Diepeveen wrote: > >>On October 14, 2002 at 07:05:42, Dave Gomboc wrote: >> >>>On October 13, 2002 at 15:35:12, Vincent Diepeveen wrote: >>> >>>>On October 13, 2002 at 14:40:12, James Swafford wrote: >>>> >>>>I wonder why. there is just one person ever in this whole >>>>planet who said 12(6) = 18 ply, and that's robert hyatt. >>> >>>Bullshit -- I said this years ago, after asking a member of the DB team. >> >>>Hsu just said it himself too: >> >>>EeEk(* DM) kibitzes: next question: Seems like people wants to know >>>what the exact meaning of ""12(6)" in the Deep Blue log files, can you >>>explain this? >>>CrazyBird(DM) kibitzes: 12(6) means 12 plies of brute force (not >>>counting the search extensions & quiescence). >> >>by definition this means: it was 12 ply not counting search extensions >>and qsearch. of course hardware search is part of that. >> >>>CrazyBird(DM) kibitzes: 6 means the maximum hardware search depth >>>allowed. >> >>that's part of that 12 ply. If you interpret it different then that's >>your problem and wrong. >> >>'brute force search' is everything including hardware. In fact hsu >>even specified it for the technical gifted that it is just >>EXCLUDING qsearch and excluding extensions. >> >>>CrazyBird(DM) kibitzes: this means that the PV could be up to 6 plies >>>deeper before quiescence. >> >>*possibly* if it prints (6), the logs clearly show that 5(6) doesn't >>show a 5 ply mainline. but < 5 >> >>>Apparently that's not clear enough for you? The PV can be up to 6 plies >>>_deeper_. Deeper than what? Than the software search of 12 plies, of course! >> >>Which country do you get from, his statement is very clear. >> >>Later it was repeated even to show the full logfile here not leaving >>away a single line after when the question is asked: >> >>---- >>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! >>aics% >>CrazyBird(DM) kibitzes: 12 total in terms of brute force. 6 is just the max >>partition in hardware. >>aics% >>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 ? >>aics% >>CrazyBird(DM) kibitzes: to all the book readers, if you do like the book, please >>tell your friends would might be interested. thanks. >>aics% >>---- >>So it is clear his answer was very clear : it is 12 ply. >> >>So is it clear now? >> >>Apart from that. For 18 ply you would need to see squareroot(40^18) >>nodes to search it using fullwidth. That's a minimal tree, excluding >>qsearch and other overhead. >> >>You really believed all that time that >>deep blue searched 40^9 = 262144000000000 nodes ? > >Where do you get 40? Is that something they published, or you came >up with? I think 35-36 would be more accurate. 35^9 is also something that they could not search. I assume it is 35 if you do not like 40. > >Also, you're assuming they aren't doing any decent move ordering. >You know as well as anyone it's possible to bring your effective >branching factor to something less than sqrt(bf). No sqrt(35^18)=35^9 is after you have perfect move ordering and it is known that nobody has perfect move ordering. Hash tables can help but it seems that they do not use it effectively and even if they could be 10 times faster thanks to hash tables 35^9/10 is still impossible. Uri
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