Author: Robert Hyatt
Date: 05:18:05 11/24/98
Go up one level in this thread
On November 24, 1998 at 03:26:30, Vincent Diepeveen 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. > >Not really. First they limit singular extensions considerable. Secondly >singular extensions aren't holy. They aren't gonna find that much extra >in games, as it is very non-human what it does. It extends only 1 move, >no matter what kind of bullshit it is. > >1.e4,h5 2. Qxh5?? 3. Rxh5 this is a singular extension already. Rxh5 is >way better than all other moves. > Please re-read their paper on SE. They don't exend such things I don't believe for obvious reasons.. In Cray Blitz, I didn't extend a capture that took the piece moved at the previous ply, ever... because I trusted my recapture extension to work there if it was important... >Searching this further is quite stupid, but that's what singular extensions >do. Only if you implement them wrong.. :) > >>There are just some things they can see at 250M+ nodes per second that we won't >>ever see... > >But positional i already see more after 3 minutes. As i'm searching deeper >than Deep Blue at nowadays PII-450. remember again, you are mixing apples and oranges. Their singular margin was something like 1/3 of a pawn or some such number. So SE isn't only finding tactical shots it is also finding positional shots as well.. > >So i'm getting like 12/13 ply after some minutes (especially 3 minutes a move >time control). Most Principal variations aren't based on Singular extensions. >If it is, then at most 1 move. > >> >> >>> >>>>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... >> >> >> >>> >>>I saw newspapers do the same mistake when a human player does a sacrifice and >>>win and they see it as a proof that the sacrifice was a good move. >>> >>>Uri >> >> >>Humans make mistakes very frequently. non-selective computers don't make these >>errors nearly so frequently. And when you consider two different types of >>programs (Cray Blitz vs Deep Thought) the likelihood of *both* making this >>mistake to let black win that bishop is *very* low indeed... As I mentioned >>before, Cray Blitz is far from a pushover...
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