Author: stuart taylor
Date: 23:12:05 08/10/00
Go up one level in this thread
On August 11, 2000 at 01:03:49, Ed Schröder wrote: >On August 10, 2000 at 21:36:23, Robert Hyatt wrote: > >>On August 10, 2000 at 17:22:17, Dann Corbit wrote: >> >>>On August 10, 2000 at 16:17:47, Christoph Fieberg wrote: >>> >>>>Unbelievable, but true: >>>>I composed a position which is mate in 1 and can easily found, but Fritz6 on >>>>Pentium III, 500 Mhz and 32 MB Hash needs more than 1 hour to show it (excatly >>>>1:03:17)!!! >>>>How do other computers react? >>>> >>>>The position is >>>>FEN: 8/8/pppppppK/NBBR1NRp/nbbrqnrP/PPPPPPPk/8/Q7 w - - 0 1 >>>> >>>>It is possible to reach this position from starting position: >>>>1.Sa3 Sa6 2.Sc4 Sc5 3.Sa5 Sa4 4.b3 b6 5.La3 La6 6.Lc5 Lc4 7.h4 h5 8.Th3 Th6 >>>>9.Td3 Te6 10.Td5 Te4 11.Sh3 Sh6 12.e3 e6 13.Le2 Le7 14.Lf3 Lf6 15.d3 d6 16.Ke2 >>>>Ke7 17.Dd2 Lc3 18.Te5 Lb4 19.Th1 Td4 20.Lc6 Dd7 21.Lb5 Th8 22.Td5 Kf6 23.Sg1 Sg4 >>>>24.Th3 Se5 25.Tg3 Kf5 26.Tf3+ Kg4 27.Tf5 a6 28.g3 c6 29.Sf3 Kh3 30.Sg5+ Kh2 >>>>31.Se4 Sg6 32.Kf3 Se5+ 33.Kf4 Sg6+ 34.Kg5 Se5 35.a3 Th6 36.c3 Tf6 37.De2 g6 >>>>38.Kh6 Sg4+ 39.Kh7 De7 40.Tf4 Tf5 41.Sg5 Df6 42.Df3 De5 43.Kg8 De4 44.Sh3 Tg5 >>>>45.Tf6 Sh6+ 46.Kh7 Sg4 47.Df5 Kg2 48.Kg7 Sh2 49.De5 Tg4 50.Sg5 Sf3 51.Sh7 Sg1 >>>>52.Df4 [52.Tf5 Se2 53.Sf6 Sf4 54.Se8 Kh2 55.Tg5 Kg2 56.Kh7 Kh2 57.Sg7 Kg2 58.Sf5 >>>>f6 59.f3 Kh2 60.Kh6 Kh3 Test it! What time do computers need to reach a certain >>>>search depths?] 52...Se2 53.Df3+ Kh2 54.Tff5 Sf4 55.Dd1 Kg2 56.Tg5 Kh2 57.Sf6 >>>>Kg2 58.Sg8 Kh2 59.Se7 Kg2 60.Sf5 Kh2 61.Da1 Kg2 62.f3 f6 63.Kh6 Kh3 Mate in 1! >>>>(64. Dh1#). What time do different programms need to show it in the display? 1-0 >>>> >>>>52.Tf5 leads to a position with White Queen on e5 (instead on a1). >>>>FEN: 8/8/pppppppK/NBBRQNRp/nbbrqnrP/PPPPPPPk/8/8 w - - 0 61 >>>> >>>>How long do computers need to reach for example depth 9? >>>>Fritz 6 reached depth 5 after 9 hours!! (on Pentium III, 500 MHz, 32 MB Hash) He >>>>showed 61. Dxe4 Txe4 62. dxe4 Lxc5 3. Txg4 hxg4 as best moves (+1.56 for White). >>>>What is the best move? >>> >>>chest finds the solution after examination of exactly one position (the first >>>one it tried): >>> >>>E:\chest-3.19>chest319 -b epd.epd >>>[D] 8/8/pppppppK/NBBR1NRp/nbbrqnrP/PPPPPPPk/8/Q7 w - - acn 1; acs 0; bm Qh1#; ce >>>32766; dm 1; pv Qh1#; >>> >>> >>>Crafty found it at ply 2: >>>E:\PROGRA~2\winboard\Crafty>crafty >>>EPD Kit revision date: 1996.04.21 >>>found computer opening book file [e:/crafty/release/bookc.bin]. >>>hash table memory = 24M bytes. >>>pawn hash table memory = 4M bytes. >>>EGTB cache memory = 2M bytes. >>>draw score set to 0.00 pawns. >>>choose from book moves randomly (using weights.) >>>choose from 5 best moves. >>>book learning enabled >>>result learning enabled >>>position learning enabled >>>threshold set to 9 pawns. >>>4 piece tablebase files found >>>1302kb of RAM used for TB indices and decompression tables >>> >>>Crafty v17.11 >>> >>>White(1): epdpfga epd.epd epd.out >>>PFGA: EPD record: 1 >>>middle-game phase >>> clearing hash tables >>> time surplus 0.00 time limit 30.00 (3:00) >>> nss depth time score variation (1) >>> 1 43.87 7.19 1. dxe4 Rxd5 2. Rxg4 hxg4 3. exd5 Bxa5 >>> 4. Bxa4 dxc5 5. gxf4 gxf5 6. bxc4 cxd5 >>> 7. cxd5 exd5 >>> 1 50.87 ++ 1. Qh1#!! >>> 1 50.87 Mate 1. Qh1# >>> 1-> 50.87 Mate 1. Qh1# >>> 2 50.87 Mate 1. Qh1# >>> 2-> 50.89 Mate 1. Qh1# >>> time=51.17 cpu=99% mat=0 n=5928139 fh=100% nps=115851 >>> ext-> checks=11 recaps=0 pawns=0 1rep=1 thrt:0 >>> predicted=0 nodes=5928139 evals=4531128 >>> endgame tablebase-> probes done=0 successful=0 >>> hashing-> trans/ref=1% pawn=92% used=0% >>> >>>I had a lot of stuff in memory, so it took crafty a long time to start up. >> >> >>That wasn't the problem. the first move searched (the one a simple eval/ >>material ordering suggests) takes forever, and millions of nodes to search. >> >>Programs that like the check first will solve it instantly. programs that >>look at something else first may well get lost in a huge tree of captures, >>and take a lot of time to get off the captures and onto the simple mating >>move. > >Here is another one that might blow up the tree on the first ply (and next >iterations) in case you don't limit q-search. > >[d]4K3/PPPPPPPP/8/8/8/8/pppppppp/4k3 w - - > >Lots of fun. > >Ed So how can we ever hope for computers to make GREAT discoveries, if we don't give them a free hand to look for everything? S.Taylor
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