Help from the 8 pieces endgame database ?

[Rein Halbersma]

Rein,

and to what extend are the error logical from a human perspective, or just to difficult to understand ?

Bert

There are two kinds of mistakes. First, black took the hardest of the available draws on move 49:


Here black played 49... 18-23!?. As Ed's analysis shows, it's still a draw. But a much quicker draw is obtained after 49... 13-19! 50. 30-24 19x30 51. 35x24 18-22 52. 27x18 21-27 53. 32x21 16x27 and now after 54. 18-12 27-31 55. 37-32 31-36 56. 12-7 36-41 57. 7-1 41-47 with a draw.

The "real" mistakes on moves 66 and 72 that Ed's analysis points out are only visible when you have the full 8 piece endgame databases. With the incomplete 8 piece databases (up to 1 king per side) the mistakes are not visible. In fact, Kingsrow with the incomplete dbs wants to play 72. 15-10 (going for another king), but that is a draw as Ed pointed out.

No human can be expected to fully understand 8 piece endgames, especially with multiple kings. So the fact that black lost the endgame is pretty understandable.

[TAILLE]

Hi

For me the mistakes made on moves 66 and 72 would have been easily avoidable.
66…26-31! is far more logical than 66…39-50?
72. 15-10? is a severe mistake because now the diagonal 15-47 is weak. Here again the move 35-30 is simply the most logical move
72…50-06? miss the fact that the diagonal 15-29 is weak. 72…45-29 or 72...50-33 are the only two logical moves.

Of course a human cannot say if the various positions encountered are winning or draw positions but the mistakes made are very easy to understand.

[TAILLE]

Hi,


White to play

In the above position black is one man down. Could white win ?

I tried 42-38 09-13 40-35 14-19 34-30 28-32 38-33 32-37 32-28


Black to play

but now after 19-23 28x19 27-32 26-21 32-38 21-17 38-43 17-12 08x17 19x08 17-21 08-02 43-49 02-16 49-27 and I did not find a win.

What is your feeling ?

[Ed Gilbert]

Gerard, kingsrow plays the same moves that you gave. It sees a database draw after 2-16. Very likely the start position is also a draw.

-- Ed

[TAILLE]

Gerard, kingsrow plays the same moves that you gave. It sees a database draw after 2-16. Very likely the start position is also a draw.

-- Ed

Thank you Ed. Very good confirmation indeed.

[FeikeBoomstra]

Roel had a big advantage, but the end result was a draw. Did he miss the winning move somewhere? Horizon can't find it! Any ideas?

Code: Select all

[Event "Nationale Clubcompetitie KNDB 2009/2010"]

[Site ""]

[White "Luteijn, Frits"]

[Black "Boomstra, Roel"]

[Result "1-1"]

[Round "6"]

[Date "2009.11.28"]


1. 32-28  17-21 2. 33-29  19-23 3. 28x19  13x33 4. 39x28  14-19 5. 37-32  10-14 
6. 44-39  21-26 7. 32-27  26x37 8. 41x32  8-13 9. 46-41  2-8 10. 41-37  5-10 
11. 39-33  19-23 12. 28x19  14x23 13. 50-44  10-14 14. 44-39  14-19 15. 49-44  9-14 
16. 34-29  23x34 17. 39x30  18-23 18. 44-39  4-9 19. 39-34  20-25 20. 34-29  25x34 
21. 29x18  13x31 22. 40x29  12-18 23. 37x26  19-23 24. 29-24  23-29 25. 24-19  14x23 
26. 33x24  7-12 27. 32-27  11-17 28. 35-30  1-7 29. 45-40  23-28 30. 38-32  28x37 
31. 42x31  17-21 32. 26x17  12x32 33. 47-42  8-13 34. 30-25  18-22 35. 40-34  7-11 
36. 34-29  22-28 37. 42-38  11-17 38. 38x27  17-21 39. 48-42  21x32 40. 42-38  6-11 
41. 38x27  11-17 42. 31-26  13-18 43. 43-39  9-14 44. 36-31  3-9 *

[Ed Gilbert]

Hi Feike,

Kingsrow agrees with most of Roel's moves after white's weak move at 20. 34-29. One exception is at 33. kingsrow prefers 18-22 and the variation I have shown below, but the attack fizzles and draws. Black can also try 7-11 at move 29, but this also draws. I could not find a win for black.

[Event "Nationale Clubcompetitie KNDB 2009/2010"]
[Site ""]
[White "Luteijn, Frits"]
[Black "Boomstra, Roel"]
[Result "1-1"]
[Round "6"]
[Date "2009.11.28"]
1. 32-28 17-21 2. 33-29 19-23 3. 28x19 13x33 4. 39x28 14-19 5. 37-32 10-14 6. 44-39 21-26 7. 32-27 26x37 8. 41x32 8-13 9. 46-41 2-8 10. 41-37 5-10 11. 39-33 19-23 12. 28x19 14x23 13. 50-44 10-14 14. 44-39 14-19 15. 49-44 9-14 16. 34-29 23x34 17. 39x30 18-23 18. 44-39 4-9 19. 39-34 20-25 20. 34-29 25x34 21. 29x18 13x31 22. 40x29 12-18 23. 37x26 19-23 24. 29-24 23-29 25. 24-19 14x23 26. 33x24 7-12 27. 32-27 11-17 28. 35-30 1-7 29. 45-40 23-28 {A} 30. 38-32 28x37 31. 42x31 17-21 32. 26x17 12x32 33. 47-42 8-13 {B} {Kingsrow sees a db draw after 8-13.} 34. 30-25 18-22 35. 40-34 7-11 36. 34-29 22-28 37. 42-38 11-17 38. 38x27 17-21 39. 48-42 21x32 40. 42-38 6-11 41. 38x27 11-17 42. 31-26 13-18 43. 43-39 9-14 44. 36-31

{A} 7-11 30. 40-35 23-28 31. 24-20 15x24 32. 30x19 28-32 33. 38-33 32x21 34. 33-29 8-13 35. 19x8 17-22 36. 26x28 9-14 37. 8x17 11x24 draw.

{B} 18-22 34. 42-38 22-27 35. 31x22 32-37 36. 40-34 6-11 37. 34-29 draw.

[FeikeBoomstra]

Hi Ed,
Thanks,
Feike

[TAILLE]

Hi Ed,


White to move

I do not manage to find a win in the above position. As a consequence I suspect the result is a draw. Can Kingsrow resolve this problem with its 8 pieces db ?

[Ed Gilbert]

Hi Gerard,

I do not manage to find a win in the above position. As a consequence I suspect the result is a draw. Can Kingsrow resolve this problem with its 8 pieces db ?

Kingsrow finds this position is a database draw. It does not quickly simplify to 8 pieces and it took a long search. I started the search this morning about 15 minutes before I left for jury duty and the score was heading towards a draw. When I returned 6 hours later the score is db draw.

-- Ed

[TAILLE]

Hi Gerard,

I do not manage to find a win in the above position. As a consequence I suspect the result is a draw. Can Kingsrow resolve this problem with its 8 pieces db ?

Kingsrow finds this position is a database draw. It does not quickly simplify to 8 pieces and it took a long search. I started the search this morning about 15 minutes before I left for jury duty and the score was heading towards a draw. When I returned 6 hours later the score is db draw.

-- Ed

Thank you very much Ed.


White to move

Can you tell me if there are mistakes in the sequence
25-20 03-09 16-32 35-40 32-28 40-49 28-05 49-35 48-43 35-02


White to move

[Ed Gilbert]

Can you tell me if there are mistakes in the sequence
25-20 03-09 16-32 35-40 32-28 40-49 28-05 49-35 48-43 35-02

No mistakes. These are all resolved to db draw.

-- Ed

[TAILLE]

Thank you again Ed.
That's a useful confirmation for me.

[TAILLE]

Hi Ed,


White to play

Could you tell me if this position is a winning position ?
If yes how can the win be obtained ?

Thank you in advance.

[Ed Gilbert]

Hi Gerard,

I am surprised that you ask about this position, because the end of the game can be seen fairly quickly without an endgame database.

There are 21 first moves by white that win. Kingsrow wants to play it out this way:
[FEN "W:WK34,K46,K49,K50:BK4,26,36,45"]
1. 34-29 4-15 2. 29-47 15-4 3. 46-23 4-31 4. 23-29 31-48 5. 29-40 45x34 6. 49-43 48x39 7. 50x28 34-40 etc.

-- Ed