Author: Robert Hyatt
Date: 13:30:32 07/22/00
Go up one level in this thread
On July 22, 2000 at 09:46:15, blass uri wrote: >On July 22, 2000 at 09:09:05, Ed Schröder wrote: > >>On July 21, 2000 at 22:40:16, blass uri wrote: >> >>>[D]2k1rr2/pp1n2p1/2p1n1p1/3pP3/5qPP/P4NR1/1PP1QP2/1K1NR3 w - - 0 1 >>>This is one of the positions from deeper blue-kasparov(game 4 before 23.Nc3) >>> >>>Deep blue claims that they could search 15 plies in 15 seconds that is >>>200,000,000*15 nodes=3,000,000,000 nodes >>> >>>I am interesting to know if you can search 15 plies with no pruning and no >>>extensions with less than 3,000,000,000 nodes. >>> >>>You can use evaluation of 0 for all the moves so you will always have a perfect >>>order of moves. >>> >>>You can use hash tables. >>>please tell me how many nodes you need to see >>>1 ply,2 plies,....15 plies and how many plies do you need to fill the hash >>>tables. >>> >>>repeat the experiment with smaller hash tables in order to guess if bigger hash >>>tables can help significantly. >>> >>>Here is Deep blue logfile in the relevant position >>> >>>3(4)[Nc3](30) 30^ T=0 >>>nd1c3 Qf4g3r pf2g3Q Rf8f3n >>> 3(5) 61^ T=0 >>>qe2e3 Qf4e3q re1e3Q Rf8f4 ph4h5 Pg6h5p pg4h5P >>> 3(5) 68 T=0 >>>qe2e3 Qf4e3q re1e3Q Rf8f4 ph4h5 Pg6h5p pg4h5P >>> 4(5) 78 T=0 >>>qe2d3 Ne6c5 qd3g6P Qf4g3r >>> 5(5)[Qd3](74)[Qe3](82)[Nc3](86) 86 T=0 >>>nd1c3 Ne6d4 nf3d4N Qf4g3r pf2g3Q Nd7e5p >>> 6(5)[Nc3](75) 75 T=1 >>>nd1c3 Pg6g5 ph4g5P Qf4g3r pf2g3Q >>> 7(5) #[Nc3](78)############################# 78 T=2 >>>nd1c3 Nd7c5 qe2e3 Qf4e3q pf2e3Q >>> 8(6) #[Nc3](61)############################# 61 T=5 >>>nd1c3 Nd7c5 pb2b4 Nc5d7 pb4b5 >>> 9(6) #[Nc3](74)############################# 74 T=15 >>>nd1c3 Nd7c5 pb2b4 Nc5d7 pb4b5 Ne6d4 nf3d4N Qf4d4n pb5c6P >>>10(6) #[Nc3](65)############################# 65 T=102 >>>nd1c3 Nd7c5 pb2b4 Nc5a6 pb4b5 Na6c5 pb5c6P Pb7c6p kb1a2 Rf8f7 >>>11(6)[TIMEOUT] 65 T=159 >>>nd1c3 >>> >>>Uri >> >>What should the experiment proof? > >The idea is to check if it is possible to get 15 plies with no prunning with the >same number of nodes. > >I am not sure if it is possible even if you assume no extensions and perfect >order of moves and in this case it proves that the depthes of Deep blue are not >brute force depths(I am sure that the depthes are not brute force but I need a >proof to convince Hyatt). > >I see from other post(of Dave) that the no pruning is probably not relevant to >Deep Blue of 1997 so if there is agreement about it and Hyatt admit that the >plies are not brute force with no pruning the experiment is not relevant. > >Uri Hyatt didn't admit that. I said that when I asked (directly) about whether deep blue did null-move or any other sort of forward pruning, the answer was _no_. They did say that the software and hardware searches were different in that the software did way more extending than the hardware did. And they did say that they added futility pruning in the q-search, but that is pretty safe based on my results (and others). Dave or Dan said they had seen something that indicated selectivity at the end of the software search. I've never seen such, but I did not specifically ask about it either. Except that they did say "no selectivity in forward pruning, period." Just selectivity in extensions... I can't say more as I don't know more, there...
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