Author: Vincent Diepeveen
Date: 11:50:15 08/21/02
Go up one level in this thread
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. >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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