Author: leonid
Date: 13:35:07 09/12/01
Go up one level in this thread
On September 12, 2001 at 16:08:11, Dann Corbit wrote: >On September 12, 2001 at 10:45:44, leonid wrote: > >>On September 12, 2001 at 10:34:41, leonid wrote: >> >>>[D]Q6r/1prpbqk1/1Q4q1/1Q1nn1p1/1Q1NN1p1/1R4q1/1BBQQRp1/K6b w - - >>> >>>Please indicate your result. > >According to chest, it's not a mate in 8. When it was said "easy mate", it was not said "easy" having in mind "brute force". By selective mate could be found very easely 10 moves deep. Move was B6-G6. Six seconds. Seven moves deep by brute force took already for mine 25 min. Celeron 600. No hash. Actually, I looked only similar position 8 moves deep. This last one was changed on the place when I found that it contain one mistake. To make it easier, black queen on h8 was replaced by black rook. Initial position took 7 hours to be verified by brute force 8 moves deep. > >Crafty can't spot it, but I did not expect 17+ ply to be exhausted: >EPD Kit revision date: 1996.04.21 >unable to open book file [e:\crafty\release/books.bin]. >hash table memory = 192M bytes. >pawn hash table memory = 80M bytes. >EGTB cache memory = 32M 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. >5 piece tablebase files found >19045kb of RAM used for TB indices and decompression tables > >Crafty v18.10 > >White(1): st 999 >search time set to 999.00. >White(1): epdpfga \t.epd t.out >PFGA: EPD record: 1 >middle-game phase > clearing hash tables > time surplus 0.00 time limit 16:39 (16:39) > nss depth time score variation (1) > 1 0.03 26.76 1. Rxf7+ Qxf7 > 1-> 0.05 26.76 1. Rxf7+ Qxf7 > 2 0.05 26.75 1. Rxf7+ Qxf7 2. Rxg3 Rxa8+ > 2-> 0.19 26.75 1. Rxf7+ Qxf7 2. Rxg3 Rxa8+ > 3 0.20 -- 1. Rxf7+ > 3 0.23 24.14 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Qh6+ > Kg8 4. Rxg3 Bxb4 5. Qdxg5+ > 3-> 0.63 24.14 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Qh6+ > Kg8 4. Rxg3 Bxb4 5. Qdxg5+ > 4 0.79 24.14 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Qh6+ > Kg8 4. Rxg3 Bxb4 5. Qdxg5+ > 4-> 2.13 24.14 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Qh6+ > Kg8 4. Rxg3 Bxb4 5. Qdxg5+ > 5 2.17 ++ 1. Rxf7+!! > 5 3.91 26.23 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Rxg3 > Bxb4 4. Qh6+ Kg8 5. Qdxg5+ Ng6 6. Qbxd5 > 5-> 8.16 26.23 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Rxg3 > Bxb4 4. Qh6+ Kg8 5. Qdxg5+ Ng6 6. Qbxd5 > 6 8.37 ++ 1. Rxf7+!! > 6 19.60 26.77 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Qh6+ > Kg8 4. Nf6+ Nxf6 5. Qdxg5+ Ng6 6. Qhxg6+ > Qxg6 7. Qxg6+ Kh8 8. Rxg3 Bxb4 9. Qxb4 > 6-> 38.74 26.77 1. Rxf7+ Qxf7 2. Qxh8+ Kxh8 3. Qh6+ > Kg8 4. Nf6+ Nxf6 5. Qdxg5+ Ng6 6. Qhxg6+ > Qxg6 7. Qxg6+ Kh8 8. Rxg3 Bxb4 9. Qxb4 > 7 40.59 ++ 1. Rxf7+!! > 7 2:39 28.64 1. Rxf7+ Qxf7 2. Nf5+ Qxf5 3. Qxh8+ > Kxh8 4. Qh6+ Qh7 5. Qxh7+ Kxh7 6. Nxg3+ > Ng6 7. Qbd4 Bc5 > 7-> 3:37 28.64 1. Rxf7+ Qxf7 2. Nf5+ Qxf5 3. Qxh8+ > Kxh8 4. Qh6+ Qh7 5. Qxh7+ Kxh7 6. Nxg3+ > Ng6 7. Qbd4 Bc5 > 8 3:37 ++ 1. Rxf7+!! > time=16:39 cpu=99% mat=22 n=589487968 fh=99% nps=590k > ext-> chk=80125742 cap=1032919 pp=36146 1rep=5779692 mate=87 > predicted=0 nodes=589487968 evals=3796048 > endgame tablebase-> probes done=0 successful=0 > >So tell me, what's the solution? It could be that if the solution will be found by Chest it will spot the next mate beside mate that start with b6-g6. He is good on brute force with excellent branching factor and huge hash. >Pretty diagram, by the way. Thanks, Leonid.
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