Author: Vincent Diepeveen
Date: 16:19:02 08/21/02
Go up one level in this thread
On August 21, 2002 at 17:27:03, Robert Hyatt wrote: >On August 21, 2002 at 14:50:15, Vincent Diepeveen wrote: > >>On August 21, 2002 at 14:48:26, Robert Hyatt wrote: >> >>Under 4.0 now already. Man you get older every day. >>You didn't read very well what i wrote about more cpu's joining in. As you did write this before reading the other replies above i will ignore this. >No, because you have no idea what you are talking about. I know how their >search worked. And I know that if you think that the branching factor keeps >getting better and better as the search goes deeper, that's ok by me. The >issue is the branching factor is below 4.0. And there is no way to do that >that I know of going pure brute-force... > > > >> >>>On August 21, 2002 at 14:25:32, Vincent Diepeveen wrote: >>> >>>>On August 21, 2002 at 12:05:12, Uri Blass wrote: >>>> >>>>>On August 21, 2002 at 11:21:18, Robert Hyatt wrote: >>>>> >>>>>>On August 21, 2002 at 10:35:13, Vincent Diepeveen wrote: >>>>>> >>>>>>>On August 21, 2002 at 10:26:57, Terry McCracken wrote: >>>>>>> >>>>>>>hello, >>>>>>> >>>>>>>Another thing. >>>>>>> >>>>>>>In 1998/1999 Hyatt claimed that deep blue searched 11 to 12 ply, >>>>>>>but that their *extensions* were better than everyone else. >>>>>>> >>>>>>>They used singular extensions. >>>>>>> >>>>>>>In 2000/2001, i also was using singular extensions, as well as >>>>>>>several other programs. >>>>>> >>>>>> >>>>>>And as I said, your implementation is pitiful compared to _real_ SE >>>>>>as implemented in Deep Thought/Deep Blue, Cray Blitz and HiTech. You >>>>>>totally fail to handle the FH-singular case which is complex and expensive. >>>>>> >>>>>>And you _also_ fail to remember that you have said _many_ times "singular >>>>>>extensions suck and what I do is much better". Only later you discover that >>>>>>your _implementation_ sucked and than when you finally got it right, then it >>>>>>did work pretty well. >>>>>> >>>>>>Which is typical for you, of course... >>>>>> >>>>>> >>>>>>> Then suddenly when we searched above 11 to 12 ply >>>>>>>depths, it was said that the 12(6) of the machine which means 12 ply >>>>>>>nominal search depth, was excluding 6 ply hardware search depth. >>>>>> >>>>>>Directly from the team, remember. I posted the email _right here_ to >>>>>>make it public... >>>>>> >>>>>> >>>>>>> >>>>>>>Which is bloody idiocy in itself, because the thing had no hashtable. >>>>>>> >>>>>>>The big theoretician Knuth has written a lemma for game tree search. >>>>>>> >>>>>>>The minimum tree to search at 18 ply search depth using alfabeta >>>>>>>(without nullmove which wasn't used by deep blue): >>>>>>> >>>>>>>2 * (squareroot(number of legal moves) ^ depth) >>>>>>> >>>>>>>or: >>>>>>> >>>>>>>2 * sqrt(40)^18 = 524288000000000 nodes needed to search it *minimum*. >>>>>>> >>>>>>>As you can imagine, getting 11 to 12 ply fullwidth search was already a >>>>>>>very good achievement in 1997. >>>>>> >>>>>> >>>>>>Again, your theoretical explanation is wrong. How do you explain that Knuth's >>>>>>"lemma" (as you wrongly call it) predicts a branching factor of > 6, when we can >>>>>>_prove_ that DB's branching factor was under 4? >>>>> >>>>>I do not think to continue to argue here but only one point: >>>>>We cannot prove that the branching factor was less than 4. >>>>> >>>>>The output is not a proof because people can choose not to believe that 12(6) >>>>>mean 18. >>>>> >>>>>If someone can make a free program with branching factor of less than 4 inspite >>>>>of no pruning(except futility pruning) then it may be interesting to see. >>>>> >>>>>Uri >>>> >>>>Look their thing could do a billion nodes a second in theory. I know >>>>very well why it is for only 1 or 2 ply a branching factor of 4. >>>> >>>>I see it in DIEP too. After a few ply slowly more and more processors >>>>you can keep busy. If they only get an average of 126MLN nodse a second >>>>of a machine which in theory is capable of doing way more, then >>>>obviously somewhere they start with 1 processor and somewhere they >>>>manage to get them all at the same time busy. >>>> >>>>That explains why the branching factor is about 5 for just ONE Ply. >>>> >>>>Note that a fail high or low is already so much longer at 11 ply that >>>>calling it branching factor 4 or 5 is already way too little. >>>> >>>>Best regards, >>>>Vincent >>> >>> >>>All you have to do is take the log files and compute it. Rather than talking >>>about how "it must be". >>> >>>I just computed the branching factor for every iteration that was completed, >>>leaving off the first one since I had nothing to compare it to (first one for >>>each search). I added them all upp and divided by N, and got something just >>>under 4.0... >>> >>>Anybody can do that again, rather than producing disinformation...
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