Author: Robert Hyatt
Date: 10:36:52 10/14/02
Go up one level in this thread
On October 14, 2002 at 11:31:35, Vincent Diepeveen wrote: >On October 14, 2002 at 04:53:28, Andreas Guettinger wrote: > >>On October 13, 2002 at 21:20:32, Robert Hyatt wrote: >> >>>On October 13, 2002 at 12:00:39, Andrew Williams wrote: >>> >>>>Several people asked: >>>> >>>>Question: What does "12(6)" mean in Deep Blue's logs? >>>> >>>>Dr Hsu said, "12(6) means 12 plies of brute force (not counting the search >>>>extensions & quiescence). 6 means the maximum hardware search depth allowed. >>>>this means that the PV could be up to 6 plies deeper before quiescence." >>>> >>>>Unfortunately questions were being fed through a third-party, so it wasn't >>>>possible to get a follow-up. >>>> >>>>Andrew >>> >>>I saw the question and answer tonight when I got back home. >>> >>>Too bad the question wasn't phrased reasonably to clear up the ambiguity. >>> >>>The above doesn't contradict the email I got from DB team members, nor does it >>>contradict the article they published. It is just too vague... >> >> >>Seems pretty clear to me what he said. The PV can be up to 6 ply deeper than 12 >>ply before quiescence search starts, this make a maximal PV length of 18 (not >>including extensions). >> >>regards >>Andreas > > >It is very clear. It is 12 ply in total including hardware depth. >That doesn't contradict with anything. Vincent, it contradicts a _lot_. The email I posted here. Searches that start off 4(5) which would be impossible by your definition. Etc... > >If they would have gotten 18 ply they would have shouted it loudly >around at this planet and sued everyone with commercial interest in >the field of computerchess who said it was 12 ply. Why? They proved they were better than anyone else... Why sue one particular person that has little credibility anyway??? > >Instead when the subject search depth comes on the agenda, the deep blue >team starts to talk about nodes a second, instead of search depth. > >Reality is that in 1997 everyone had a branching factor of between 6 and 10. Reality is that you make idiotic statements. Just compute the branching factor for Deep Blue. It was just under 4.0 for game 1. And Crafty in 1995 did _not_ have a branching factor of 6-10, so I have absolutely no idea why you are making up such numbers, but several have copies of the Jakarta version of Crafty (1996) and it _certainly_ didn't have a branching factor of 5 or more... That is _easy_ to settle as the Jakarta version is still around... Stop spouting absolute rubbish. _you_ might have had such a terrible branching factor. Deep Blue did not, as their logs show, and I certainly didn't, nor did at least Ferret as we swapped logs all the time. > >They had around 6.0 to 10.0, so that's not so bad as it looks like. They >just got more nodes a second. the improvements in b.f. started later when >hashtables and nullmove started to work well together and R=2 was changed >to R=3 by most. Why don't you offer some real data, since the logs are public. They might have a 6-10 EBF at some point in a game. I have them myself in bad cases, but I certainly don't _averate_ 6-10 and neither did they, nor anybody else I know of in 1996-1997... > >The statement is very clear when asked whether it was 12 ply or 18 ply >in total the answer was: 12. > >Very clear. > >And that he better could say so, because it is impossible to search >18 ply fullwidth: > And again, they have now revealed that they did forward pruning, so your statement is 100% pointless... >According to Knuth, it is > 2* squareroot(40^18) = 524.288.000.000.000 nodes > >Or do you disbelief the proof of Knuth about what the minimal tree is >that you have to search with alfabeta? > First, 40 is wrong. 35-38 is accepted as the _real_ number. But when you do forward pruning, then 35-38 drops drastically, which invalidates the entire formula. You are simply mis-using it. Nobody says the formula is wrong. Your use of the formula is wrong, however... >If you do not, cut the nonsense please, and get back to normal. > >Most searched like 8-9 ply in 1997. They get 12 ply. They didn't get >twice the search depth at all of course. Stories about 18 ply nominal >search depth is complete nonsense. I got 12 plies in 1996. Ferret did the same. > >Even Knuth proved it to be impossible. > >Now they have this machien that's just busy getting a hell of a lot of >nodes a second. > >You have a statement from Hsu that he cares less for searching deeper >than doing a bunch of extensions. > >Bob claims they lost 2 ply to extensions. > >And you still believe it is 18 ply? > I don't claim that. I said that in Cray Blitz, SE cost me one ply all the time, and _sometimes_ two plies... >So without those extensiosn that would be 20 ply. > >Want to know what the minimal tree is for 18 ply search when searching >fullwidth without hashtable? > >2 * squareroot(40^20) = 20.971.520.000.000.000 > >Or 2.0 * 10^16 nodes > >MINIMAL tree. > based on an inflated branching factor of 40, which is wrong, when someone is doing forward pruning... >So not realistic tree. Add another huge factor to that for the >realistic tree. > >How naive are we still today? > >WHY THE HELL IS HYATT STILL PUTTING OIL IN THE FIRE? \ I'm not. _you_ are the one making ridiculous statements. But that is normal it seems... > >He'll realize as the best that it's 12 ply and that 12 ply was great in 97. > >Whether he got that too at his cray is not important. Of course it isn't important. Nothing is important to the discussion except your twisted/defective opinion...
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.