Author: Bas Hamstra
Date: 13:32:01 06/18/01
Go up one level in this thread
On June 18, 2001 at 11:57:41, Ulrich Tuerke wrote: >On June 18, 2001 at 11:19:41, Bas Hamstra wrote: > >>On June 18, 2001 at 10:40:55, Ulrich Tuerke wrote: >> >>>On June 18, 2001 at 10:25:36, Uri Blass wrote: >>> >>>>On June 18, 2001 at 10:01:45, Ulrich Tuerke wrote: >>>> >>>>>On June 18, 2001 at 08:54:10, Uri Blass wrote: >>>>> >>>>>>On June 18, 2001 at 08:33:21, Ulrich Tuerke wrote: >>>>>> >>>>>>>On June 18, 2001 at 08:28:08, Bas Hamstra wrote: >>>>>>> >>>>>>>>On June 17, 2001 at 01:09:50, Robert Hyatt wrote: >>>>>>>> >>>>>>>>>On June 16, 2001 at 22:59:06, Vincent Diepeveen wrote: >>>>>>>>> >>>>>>>>>>Hello, >>>>>>>>>> >>>>>>>>>>From Gian-Carlo i received tonight a cool version of crafty 18.10, >>>>>>>>>>namely a modified version of crafty. The modification was that it >>>>>>>>>>is using a small sense of Singular extensions, using a 'moreland' >>>>>>>>>>implementation. >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>>Instead of modifying Crafty to simulate Deep Blue, why didn't you >>>>>>>>>modify Netscape? Or anything else? I don't see _any_ point in >>>>>>>>>taking a very fishy version of crafty and trying to conclude _anything_ >>>>>>>>>about deep blue from it... >>>>>>>>> >>>>>>>>>Unless you are into counting chickens to forecast weather, or something >>>>>>>>>else... >>>>>>>> >>>>>>>>I don't agree here. It is fun. Maybe not extremely accurate, but it says >>>>>>>>*something* about the efficiency of their search, which I believe is horrible. I >>>>>>>>think using SE and not nullmove is *inefficient* as compared to nullmove. We >>>>>>>>don't need 100.0000% accurate data when it's obviously an order of magnitude >>>>>>>>more inefficient. >>>>>>> >>>>>>>May be you are right, if the program is running on a PC. However if you can >>>>>>>reach a huge depth anyway because of hardware, may be you can afford to use >>>>>>>this, because it doesn't matter too much wasting one ply depth ? >>>>>> >>>>>>It is not about wasting one ply but about clearly more than it and >>>>>>it is clear that not using null move is counter productive when the difference >>>>>>becomes bigger and not smaller at longer time control so the fact that they had >>>>>>better hardware only supports using null move. >>>>> >>>>>How can you be so sure ? Do you really know that all of the top programs are >>>>>using null move. I wouldn't bet too high on this. There may be viable >>>>>alternatives to this, though not being published. >>>> >>>>I know that Junior and Rebel do not use null move but they use other pruning >>>>techniques. >>>> >>>>I do not believe that the technique of no pruning+singular extension is good at >>>>long time control and this is the point. >>> >>>You may be right or not. Who knows ? >>>Who really knows the program of the Deep Blue guys ? >>>IMHO, the discussion is far too speculative. >>> >>>I guess that these gentlemen were knowing very well what they were doing. >>>I think that it's almost some kind of arrogance, to disqaulify their program >>>without knowing a thing. Isn't it ? >> >>Now you sound exactly like Bob. > >Well, may be, he isn't always wrong. -:) > >>Noone is disqualifying their program. At the >>time unbeatable. But it *is* possible to compare search model A with search >>model B and conclude that B is better. DB is not a magical black box that we >>know absolutely about. We know they didn't prune. So they could have even been >>stronger. > >I just doubt that the comparison is possible, because they had a completely >different platform with charactistics being basically different from what we >used to. So, for example, search coasted practically nothing compared to >evaluation because it was done by hardware. You would have to simulate this >too.For instance, searching an extra ply deeper by use of SE wasn't a big >problem for them. But it may be a problem for a PC program. I don't see this. If search was free, they had the choice to burn many nodes in extensions or they could get extra depth. Suppose they had a reasonable qsearch, then at depth-2 you miss hardly anything. Then they had the choice: a) Seeing 20 ply positionally, not missing anything up till 18 ply b) Searching 16 ply and not missing anything, with SE on top of that That's the situation, and I don't see where DB differs here from a PC program. To use the standard joke: if A plays B, B sees first that it gets mated :-) >May be, I'm just a bit stubborn, but I keep on being very sceptical about >Vincent's approach. Depends on what he is going to do, I'm not sure. Of course his first post has a provocative title, but I am interested in some results anyway. Best regards, Bas.
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