Author: Amir Ban
Date: 00:03:49 02/04/00
Go up one level in this thread
On February 04, 2000 at 02:57:37, Amir Ban wrote: >On February 04, 2000 at 00:02:09, Robert Hyatt wrote: > >>On February 03, 2000 at 17:08:37, Amir Ban wrote: >> >>> >>>There's an article by Nunn & Friedel in the latest ICCAJ called "Brains of the >>>Earth" on a contest to solve 6 very hard king & pawn endings. The article says >>>solving this suite in 24 hours was an exceptional achievement, and Kasparov made >>>an amazing achievement of solving it in 45 minutes. It's also possible to >>>understand from the article that Hiarcs could not solve the set. >>> >>>So I set up the EPD, intending to let Junior think about it all night, but I was >>>surprised to find that Junior (no tablebases) can find all 6 key moves in less >>>than 2 minutes each. >>> >>>Here is the EPD: >>> >>>6k1/6p1/8/4K1P1/8/7P/8/8 w - - ; bm Kf4; >>>k7/4p3/4p3/8/8/3P1P2/5P2/K7 w - - ; bm Kb2; >>>8/4p3/2kp4/4p3/6K1/5P2/3P4/8 w - - ; bm Kg5; >>>k7/8/1p6/p1p5/2P4K/8/PP6/8 w - - ; bm a4; >>>8/8/p7/8/1P6/7p/P4k1P/3K4 w - - ; bm a3; >>>8/5p1p/8/6k1/8/6P1/5PP1/7K w - - ; bm Kh2; >>> >>>I don't quite understand it. >>> >>>Amir >> >> >>position 1: >> >>White(1): 6k1/6p1/8/4K1P1/8/7P/8/8 w - - >>1. Kf4 Kf8 2. Kg4 Kg8 3. Kh5 Kh7 4. Kh4 Kh8 5. Kg3 Kh7 6. Kf4 Kg6 >>7. Kg4 Kf7 8. Kh5 Kf8 9. Kg6 Kg8 10. h4 Kh8 11. h5 Kg8 12. h6 gxh6 >>13. Kxh6 Kf7 14. Kh7 Ke6 15. g6 Kd5 16. g7 Kc4 17. g8=Q+ Kc3 18. >>Qf8 Kb2 19. Qc5 Ka1 20. Qb6 Ka2 21. Kg7 Ka1 22. Kf6 Ka2 23. Ke5 Ka1 >>24. Kd4 Ka2 25. Kc3 Ka1 26. Qb2# >> >>position 2: >> >>I think this must be obvious. Kb2 is the _only_ move I get. My first output >>is at ply=14, with Kb2 as the move. I stopped it at depth=28, 30 seconds, >>move was still Kb2, eval still +1.5 >> >>position 3: >> >>Kg5 is the only move I get from the first printed output thru 25 plies. Score >>is -1.0, but no other move ever shows up as better... >> > >This is white to draw. The critical line continues 1...Kd7 2.Kh6! > >[D]8/4p3/3p4/3kp3/8/5PK1/3P4/8 w - - ; bm Kh6; > Should be: [D]8/3kp3/3p4/4p1K1/8/5P2/3P4/8 w - - ; bm Kh6; >>position 4: >> >>a4 is also the only move I get, from the first output at 14 plies thru 27 plies >>where I stopped it. eval=.36, so it isn't crushing... but it does agree with >>the move. >> > >The critical line continues 1...Kb7 2.Kh5! > >[D]8/1k6/1p6/p1p5/P1P4K/8/1P6/8 w - - ; bm Kh5; > >>position 5 >> >>a3 is found instantly. And it is crushing. By ply 24, 30 seconds, score is +7 >>and climbing every iteration. >> >>position 6. >> >>The first "hard" one (one that takes over a few milliseconds to get the >>suggested best move). Crafty likes Kg1 until depth 22, 20 seconds. At >>that point it switches to Kh2 and sticks with it. >> >>Interesting that it takes the best player in the world 45 minutes, a strong >>GM 24 hours, and a computer only 60 seconds _total_. >>Perhaps the computers just excel at this kind of position since they can reach >>extreme depths quickly... >> > >You only need to look at the solution to no. 1, which may be the simplest one, >and look at the weird king walk to h4 and back, to see why this is very >difficult. All of these positions have subtle and elaborate solutions. I can't >even imagine how a GM tackles such problems, let alone solve them. > >Amir > > >>Note that I did run them with tablebases...
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