Author: James T. Walker
Date: 10:31:38 02/02/01
Go up one level in this thread
On February 02, 2001 at 13:28:18, James T. Walker wrote: >On February 02, 2001 at 12:39:31, Timothy J. Frohlick wrote: > >>On February 02, 2001 at 12:10:58, James T. Walker wrote: >> >>>On February 02, 2001 at 03:19:14, Timothy J. Frohlick wrote: >>> >>>>On February 02, 2001 at 01:28:59, Jouni Uski wrote: >>>> >>>>>[D]8/6kn/3B3p/5K1B/8/8/8/8 b - - >>>>> >>>>>resign 1-0! Why? Is this really white's win? >>>>> >>>>>JouniDate: 1/2/2001 >>>> >>>>Jouni, >>>> >>>>Gambit Tiger without tablebases solves this as a mate in 46 in 26 minutes on a >>>>PII 333 with 48 Megs Hash. >>>> >>>>1... Ng5 2. Bc5 Nf7 3. Bd4+ Kf8 4. Kf6 Ng5 5. Bc5+ Kg8 6. Kf5 Nf7 7. Be7 Ng5 8. >>>>Bb4 Nf7 9. Kg6 Ne5+ 10. Kf6 Nd7+ 11. Ke7 Ne5 12. Bc3 Nc6+ 13. Ke8 Kh7 14. Kf7 >>>>Ne5+ 15. Kf6 Nc6 16. Bf3 Nd8 17. Bb4 h5 18. Be4+ Kh8 19. Be7 Nc6 20. Bxc6 Kh7 >>>>21. Be4+ Kg8 22. Kg6 Kh8 23. Bd5 h4 24. Bf6# >>>> >>>> >>>>1-0 >>>> >>>>Maybe tablebases are not all that great after all. They don't always find the >>>>shortest solution to a problem. >>>> >>>>Tim Frohlick >>> >>>Why mate in 46 and then you give a mate in 24 line? I believe the "mate in 46" >>>is true as Shredder 5 finds a mate in 47 (maybe a difference in terms) but where >>>did the above line which is 24 moves come from? >>>Jim >> >> >>Jim, >> >>Mate in 46 ply or 23 moves that is. I do believe that this is the shortest >>mate. It sounds better to say the bigger number even though that is not how you >>claim "mate in". What I did to solve the above problem was to let GT run out to >>14 or 15 ply seaarches and hand-pick the end move. It seems that the "horizon >>effect" can be partially eliminated by this method. In addition, I think that >>GT would not even get to a 46 ply search in a week of searching on a 333 Pentium >>II. The intelligent way to solve these long mate problems without a tablebase >>is to do what I have done. >> >>It is not "Green" ie environmentally friendly to let one's computer run for days >>just to solve one chess problem.. N'est pas? >> >>Tim "Save the Electrons" Frohlick > >Hello Tim, >Well I don't believe the mate in 23/24 moves. I seriously doubt that Tiger >could mate any of the top programs in 23 moves and I think the tablebases are >the best method to find mate here. It is interesting to me that the different >programs all using the same tablebases find different distances to mate here. >Although the shortest was mate in 46/47 some found mate in 74 (Fritz 6)and some >found mate in 49 (Junior 6) and all used the same tablebases to find these >scores. >Regards, >Jim Hello again, While typing the above post Fritz found a mate in 35 (31:17) so who knows? If given more time it may yet find one shorter. Jim
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