Author: Robert Hyatt
Date: 14:06:33 11/23/98
Go up one level in this thread
On November 23, 1998 at 11:36:44, blass uri wrote: > >On November 23, 1998 at 09:37:25, Robert Hyatt wrote: > >>On November 22, 1998 at 11:49:54, blass uri wrote: >> >>> >>>I did not ask for all the tree but only the tree up to the point that my >>>programs can see by search of 3 minutes that black has at least 1 pawn >>>advantage. >>> >>>This is clearly less positions >>>because if in the leaves it is -2.xx then Junior can see some moves before the >>>leaves that it is -1.xx >> >> >>ok... rather than 10 million pages, it might only be 1 million pages. How >>would we get those to you? :) >> >>what you are overlooking is the point that junior (and all the other programs) >>look at a fat, shallow tree. IE how do you think a program like Crafty, doing >>300K nodes per second, reaches 12 plies in the middlegame, while Deep Blue, >>doing 1,000 times as many nodes per second, only reaches to 10-11 plies in the >>middlegame? Because *they* are searching 10 times deeper than I am on most >>moves, thru their "singular extensions" (and other extensions). We've already >>seen that in the Deep Blue vs Kasparov game two, Dark Thought and Ferret have >>searched axb5/Qb6 to depth 20 or 21 without seeing anything to cause it to fail >>low, yet we know deep blue did. At 1/2 that depth. So it might take a program >>like junior *fifty* plies to find what is going on there for all I know at >>present. And if I could somehow give you a PV to get you down to the point >>where Junior sees this, it would be so deep, probably, that it would be easy >>to say "but this isn't the best move, white or black should try this instead. >>And we end right back up at square zero. >> >>There are just some things they can see at 250M+ nodes per second that we won't >>ever see... > >we are discussing about deepthought 2 game and not about deeper blue >deepthought could not calculate 250M+ nodes per second Right... so rather than 1,000,000 pages of output, maybe we cut that down to 50,000 pages... which is 100 packages of 500 sheets each, or a stack of paper about 200 inches tall... still a tad too much? > >> >> >> >>> >>>>I don't have their "output" for this move. As I said before, we sat at the >>>>same table playing this game at the 88 ACM event (I think). I saw their output, >>>>they saw ours. We both saw them fail high with a score > 2.0, while we were >>>>reasonably happy with our score... until the roof fell in about 10 moves >>>>later... and their eval didn't vary by much for the entire sequence... So I >>>>can't give you their output, since I don't have it (they were using a laptop >>>>to display their stuff). I can only tell you what actually happened in the >>>>game. >>> >>>I believe that cray blitz lost because of a mistake that came after c5(maybe at >>>move 32 because I do not see what is wrong with 32.Bg5) >>>The fact that they have score>2.0 does not prove that they were right in the >>>evaluation. >> >> >>You'll have to believe what you want here. I *know* that a program that doesn't >>do any selective forward pruning and which doesn't use null-move is *not* going >>to make that kind of mistake, except perhaps for some sort of horizon effect on >>the end where they can't actually take the piece due to a mate threat or some- >>thing more serious. But that's not the case in this position... > >There can be a mistake in the evaluation function >They may evaluate -2.xx something that top programs evaluates as -0.xx > >Uri Remember that another "top program" fell into this hole... and there isn't a current commercial program around that can search as fast as Cray Blitz. So it didn't quite "roll over". In 1988 we were doing about 1M nodes per sec or so... And I really like this concept that "top programs" are more accurate than deep thought was. Where were these "top programs" in the ACM events of those years? It's a strong "anti-DB mindset" that keeps this sort of discussion going.
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