Author: Ed Schröder
Date: 22:03:49 08/10/00
Go up one level in this thread
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
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