Author: Amir Ban
Date: 23:57:37 02/03/00
Go up one level in this thread
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; >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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