Author: leonid
Date: 19:45:11 05/23/01
Go up one level in this thread
On May 23, 2001 at 19:35:00, Heiner Marxen wrote: >On May 23, 2001 at 15:37:07, leonid wrote: > >> >>>Hey, Leonid, what about some problems with lots of pawns? >>>That sort of piece is missing in your creations, up to now, right? >> >>Hi, Heiner! >> >>I don't use that much pawns since they signify little mobily. This last position >>came just from three close positions that had pawns. If I presented before >>without pawns it is because it was the simplest one. Very few people here are >>ready for some deep thinking before week-end. Now you can see the other two, >>even if initially I expected to write only deepest mate. Anyway, both positions >>are very easy and accessible for every possible program. They have limited >>number of moves to start. Everybody can try and solve them. >> >>[D]RqqkqqR1/rPNbNPr1/QnqBqnQ1/bqRQRqb1/Q2K2Q1/3B4/8/8 w - - > >This one is quite easy even for Chest's brute force attack: K7/600, 47.74 sec. >Six key moves lead to mate in 9: Pretty good time! Mine found only after 13 min that mate not exist in 8 moves. Mate in 9 (first mate) was found in 1 min and 23 sec. Selective do good work here. It find mate in 9 moves in 3 sec. > >Nxc6+ Qxc6 fxe8Q+ Nxe8 bxc8Q+ Qxc8 Nxe6+ Qxe6 Q4xg5+ Qee7 Bxe7+ Qxe7 >Rxe8+ Kc7 Rxc6+ Bxc6 Qgxc6# > >Nxe6+ Qxe6 fxe8Q+ Nxe8 Nxc6+ Qbxc6 Q4xg5+ Re7 Bxe7+ Qfxe7 bxc8Q+ Nxc8 >Qxe8+ Kc7 Qd8+ Qxd8 Qxd8# > >bxc8Q+ Nxc8 fxe8Q+ Qxe8 Nxc6+ Qxc6 Nxe6+ Qxe6 Q4xa5+ Qbc7 Be7+ Kxe7 >Rxe6+ Bxe6 Qgxe6+ Qxe6 Qaxe6# > >bxc8R+ Nxc8 fxe8Q+ Qxe8 Nxc6+ Qxc6 Nxe6+ Qxe6 Q4xa5+ Qbc7 Be7+ Kxe7 >Rxe6+ Bxe6 Qgxe6+ Qxe6 Qaxe6# > >fxe8Q+ Nxe8 bxc8Q+ Qxc8 Nxc6+ Qxc6 Nxe6+ Qxe6 Q4xg5+ Qee7 Bxe7+ Qxe7 >Rxe8+ Kc7 Rxc6+ Bxc6 Qgxc6# > >fxe8R+ Nxe8 bxc8Q+ Qxc8 Nxc6+ Qxc6 Nxe6+ Qxe6 Q4xg5+ Qee7 Bxe7+ Qxe7 >Rxe8+ Kc7 Rxc6+ Bxc6 Qgxc6# > >>[D]RrqkqrR1/qPNbNPq1/BnqBqnB1/bqQQQqb1/Q2K2Q1/3B4/8/8 w - - > >This one has an even smaller effective branching factor. It has the same >set of solution moves, but it is a mate in 12: Here I was not sure where is the mate. Your finding is useful. 10 moves took already 6 hours and 28 minutes to say that no mate exist. For 11 moves it could be expected as 50 hours. Branching factor started to grow for my program just after 7 moves. It was between 4 and 5 move - 5.4. Mate was found for sure in 13 moves by selective. Took 7 sec. Big number of possible solutions make this position quit useful for possible logic verification. Cheers, Leonid. >Nxc6+ Qxc6 bxc8Q+ Rxc8 Nxe6+ Qfxe6 fxe8Q+ Rxe8 Rxe8+ Nxe8 Qxg5+ Nf6 Rxc8+ > Nxc8 Qxa5+ Nb6 Qexe6 Qa4+ Qxa4 Bc6 Be7+ Kc7 Qge5# > >Nxe6+ Qxe6 fxe8Q+ Rxe8 Nxc6+ Qbxc6 bxc8Q+ Rxc8 Rxe8+ Nxe8 Qxg5+ Nf6 Rxc8+ > Nxc8 Qxa5+ Nb6 Qexe6 Qa4+ Qxa4 Bc6 Be7+ Kc7 Qge5# > >bxc8Q+ Rxc8 fxe8Q+ Rxe8 Nxc6+ Qxc6 Nxe6+ Qxe6 Rxe8+ Nxe8 Qxg5+ Nf6 Rxc8+ > Nxc8 Qxa5+ Nb6 Qexe6 Qa4+ Qxa4 Bc6 Be7+ Kc7 Qge5# > >bxc8R+ Rxc8 fxe8Q+ Rxe8 Nxc6+ Qxc6 Nxe6+ Qxe6 Rxe8+ Nxe8 Qxg5+ Nf6 Rxc8+ > Nxc8 Qxa5+ Nb6 Qexe6 Qa4+ Qxa4 Bc6 Be7+ Kc7 Qge5# > >fxe8Q+ Rxe8 bxc8Q+ Rxc8 Nxc6+ Qxc6 Nxe6+ Qxe6 Rxe8+ Nxe8 Qxg5+ Nf6 Rxc8+ > Nxc8 Qxa5+ Nb6 Qexe6 Qa4+ Qxa4 Bc6 Be7+ Kc7 Qge5# > >fxe8R+ Rxe8 bxc8Q+ Rxc8 Nxc6+ Qxc6 Nxe6+ Qxe6 Rxe8+ Nxe8 Qxg5+ Nf6 Rxc8+ > Nxc8 Qxa5+ Nb6 Qexe6 Qa4+ Qxa4 Bc6 Be7+ Kc7 Qge5# > >Although only 40MB hash have been used, it helped a lot (factor 13). >K7/600, 163.78 sec. > >Cheers, >Heiner
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