Author: Robert Hyatt
Date: 14:19:21 07/06/02
Go up one level in this thread
On July 06, 2002 at 11:03:42, Uri Blass wrote: >On July 06, 2002 at 10:25:44, Robert Hyatt wrote: > >>On July 06, 2002 at 01:28:07, Ricardo Gibert wrote: >> >>> >>>When I read in CCC that the Deep Blue search had an EBF of about 4, my thoughts >>>were, "Ugh! That means that in about 50 years of the expected hardware >>>improvements, the PC programs of the day will be able to surpass Deep Blue even >>>if Deep Blue were to get the commensurate hardware improvements." >> >>The problem is that you are making a _classic_ mistake. The EBF has _nothing_ >>to do with how the two programs will compare. What is important is the _tree_ >>that both search. If one does a 20 ply search, and the other does a 10 ply >>search, but they search the same tree, then they play equally tactically. >> >>Don't get hung up on a 20 ply search depth (iteration number). It doesn't >>mean a thing when compared to _other_ programs.. >> >> >> >>> >>>The big advantage in EBF of the then current programs is like a juggernaut that >>>cannot be stopped. That I was not impressed with Deep Blue is an understatement. >>>Deep Blue was superior...then, but this was *despite* its method of search. Its >>>hardware made it superior and not its search methods. >> >> >>Its search methods are far from primitive. IE they have been doing singular >>extensions since the late 1980's. Others started to copy the idea much later. > > >I am interested to know about a single programmer who copied the way that they >used singular extensions. OK... first, me, in Cray Blitz. 1994. GCP modified Crafty and used the Hsu-definition of SE in doing so. Hans Berliner did SE in Hitech. Dave Kittinger did the PV-singular implementation as defined by Hsu. He did not do the FH-singular part however, as it was too expensive for his tastes and since he was using a micro, that might have been reasonable. We know Genius used this around version 2 or 3, although no details about how it was implemented were ever published... >There are programmers who use singular extensions but I know about no programmer >of one of the top programs of today that use it in the way that they use it. So? They choose to implement a less-than-optimal version to control the computational cost. The DB guys didn't have to give much thought to the computational cost at the speed they were searching. Again, an apples-to- oranges comparison when one side worries about speed while the other side doesn't have to. > >If their ideas about singular extensions were so good how is it possible that >nobody copied their algorithm succesfully until today and even people who use >singular extensions(bruce moreland) use inferior algorithm if we believe you >about it. > Several _have_ copied it. I gave you several names above. >Is their algorithm about singular extensions a secret? > How could it be when it was published in the JICCA several years ago, in full detail? >Uri
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