Author: Mike Byrne
Date: 13:09:06 12/30/03
Go up one level in this thread
On December 30, 2003 at 13:33:57, Michael Henderson wrote: > >Crafty v 19.2 gives the following analysis for Fine #70, starting at ply 36: > >8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - - 0 1 > > depth time score > > 36 1.25 5.17 1. Kb1 Kb7 2. Kc1 Kc7 3. Kd1 Kc8 4. > Kd2 Kc7 5. Kd3 Kb7 6. Ke2 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 <HT> > 36-> 1.25 5.17 1. Kb1 Kb7 2. Kc1 Kc7 3. Kd1 Kc8 4. > Kd2 Kc7 5. Kd3 Kb7 6. Ke2 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 <HT> > 37 1.27 -- 1. Kb1 > 37 1.45 4.68 1. Kb1 Kb7 2. Kc1 Kc7 3. Kd1 Kc8 4. > Kd2 Kc7 5. Kd3 Kb7 6. Ke2 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 Kg7 > 14. f5 Kf7 15. f6 Kf8 16. Kg4 Kg8 17. > Kf4 Kf8 18. Ke4 Ke8 19. Kf5 > 37-> 1.45 4.68 1. Kb1 Kb7 2. Kc1 Kc7 3. Kd1 Kc8 4. > Kd2 Kc7 5. Kd3 Kb7 6. Ke2 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 Kg7 > 14. f5 Kf7 15. f6 Kf8 16. Kg4 Kg8 17. > Kf4 Kf8 18. Ke4 Ke8 19. Kf5 > 38 2.59 ++ 1. Kb1!! > 38 10.26 6.71 1. Kb1 Kb7 2. Kc1 Kb8 3. Kc2 Kb7 4. > Kc3 Kc7 5. Kd3 Kb7 6. Ke3 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 <HT> > 38-> 10.26 6.71 1. Kb1 Kb7 2. Kc1 Kb8 3. Kc2 Kb7 4. > Kc3 Kc7 5. Kd3 Kb7 6. Ke3 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 <HT> > 39 10.49 -- 1. Kb1 > > > >I will take the ply 36 analysis to illustrate the specific problem: > > depth time score > > 36 1.25 5.17 1. Kb1 Kb7 2. Kc1 Kc7 3. Kd1 Kc8 4. > Kd2 Kc7 5. Kd3 Kb7 6. Ke2 Kc7 7. Kf3 > Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > 11. Kg5 Kg7 12. Kxf5 Kf7 13. Kg5 <HT> > >36 plies is more than enough plies to see the winning capture Kxf5. The key > >position is after 4. Kd2. Black has a choice of playing either Kc7 or Kd7. > >Kd7 holds off the winning capture (Kxf5) two more plies than Kc7. Crafty > >wants to play 4. ...Kc7 in the analysis. Here is the key position FEN: > >2k5/8/3p4/p2P1p2/P2P1P2/8/3K4/8 b - - 0 1 >Crafty gives this analysis starting from the position after 4. Kd2 > > > depth time score > > 36 1:02 7.10 1. ... Kd7 2. Kc3 Kc7 3. Kd3 Kb6 4. > Ke3 Kc7 5. Kf3 Kd7 6. Kg3 Ke7 7. Kh4 > Kf6 8. Kh5 Kf7 9. Kg5 Kg7 10. Kxf5 > Kf7 11. Ke4 Kf6 12. Kd3 Kf5 13. Kc4 > Kxf4 14. Kb5 Ke4 15. Kxa5 Kxd5 16. > Kb5 Kxd4 17. a5 d5 18. Kb6 Kd3 19. > a6 > 36-> 1:02 7.10 1. ... Kd7 2. Kc3 Kc7 3. Kd3 Kb6 4. > Ke3 Kc7 5. Kf3 Kd7 6. Kg3 Ke7 7. Kh4 > Kf6 8. Kh5 Kf7 9. Kg5 Kg7 10. Kxf5 > Kf7 11. Ke4 Kf6 12. Kd3 Kf5 13. Kc4 > Kxf4 14. Kb5 Ke4 15. Kxa5 Kxd5 16. > Kb5 Kxd4 17. a5 d5 18. Kb6 Kd3 19. > a6 > >So, the from Fine #70, crafty gives this line after 4.Kd2: > >4. ... Kc7 5. Kd3 Kb7 6. Ke2 Kc7 7. Kf3 Kd7 8. Kg3 Ke7 9. Kh4 Kf6 10. Kh5 Kf7 > >11. Kg5 Kg7 12. Kxf5 > >while, starting from the position after 4.Kd2, we are given this line: > >4. ... Kd7 5. Kc3 Kc7 6. Kd3 Kb6 7. Ke3 Kc7 8. Kf3 Kd7 9. Kg3 Ke7 10. Kh4 Kf6 > >11. Kh5 Kf7 12. Kg5 Kg7 13. Kxf5 > >I would think that black would try to delay the loss two more plies from Fine >#70 with Kd7, or does it see Kc7 because black will lose anyway? > >thx for reading, >Michael Henderson the best bet is do not get hung up on pv lines -- they often are not the best ..a chess engine just go by the score in a given end node - but not all end nodes are created equal , some are deeper than others ...so a quicker line may not look like a better position because the engine has not searched all lines to the same depth... as an example here is a totally different line that a modified Crafty 19.08 SE sees after a few minutes - it varies with your move on 2.Kb8 -- why 2.Kb8 ..it may not have search that line as deep as other lines and that line has a better score for black... Crafty19.08 SE 32 02:32 10.10 1.Kb1 Kb7 2.Kc1 Kb8 3.Kc2 Kc7 4.Kd3 Kb6 5.Ke3 Kc7 6.Kf3 Kd7 7.Kg3 Ke7 8.Kh4 Kf6 9.Kh5 Kf7 10.Kg5 Kg7 11.Kxf5 Kf7 12.Ke4 Kf6 13.Kd3 Kf5 14.Kc4 Ke4 15.Kb5 Kxd5 16.Kxa5 Kc4 17.Kb6 d5 18.f5 Kxd4 19.f6 Ke5 20.f7 d4 21.a5 d3 22.f8Q
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