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Subject: Re: Simple Endgame for programs without TBs ??

Author: Robert Hyatt

Date: 17:40:51 11/22/00

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On November 22, 2000 at 20:43:48, Robert Hyatt wrote:

>On November 22, 2000 at 20:28:50, Andrew Dados wrote:
>
>>On November 22, 2000 at 14:06:22, Robert Hyatt wrote:
>>
>>>On November 22, 2000 at 12:32:47, Bruce Moreland wrote:
>>>
>>>>On November 22, 2000 at 03:55:13, Jeremiah Penery wrote:
>>>>
>>>>>On November 22, 2000 at 00:02:34, Bruce Moreland wrote:
>>>>>
>>>>>>On November 21, 2000 at 20:24:31, Jeremiah Penery wrote:
>>>>>>
>>>>>>>On November 21, 2000 at 20:11:10, Bruce Moreland wrote:
>>>>>>>
>>>>>>>>What does Crafty think of the Reti study:
>>>>>>>>
>>>>>>>>[D]7K/8/k1P5/7p/8/8/8/8 w - - 0 1
>>>>>>>>
>>>>>>>>White to move draws.  I might have this slightly wrong, because I'm constructing
>>>>>>>>it from memory.
>>>>>>>>
>>>>>>>>bruce
>>>>>>>
>>>>>>>I get a drawscore at ply 9 from Crafty in this position.
>>>>>>>
>>>>>>>This is the last line I got:
>>>>>>>
>>>>>>>22->    1:01  -0.50   1. Kg7 Kb6 2. Kf6 Kxc6 3. Kg5 h4 4.
>>>>>>>                      Kxh4 Kc7 5. Kh5 Kb6 6. Kh6 Ka5 7. Kg6
>>>>>>>                      Kb6 8. Kh5 Ka5 9. Kh6 Kb6 10. Kg6 Ka5
>>>>>>>                      11. Kh5 Kb6
>>>>>>
>>>>>>What interests me would be the scores prior to that ply, where Crafty things
>>>>>>white is going to hit a home run.
>>>>>>
>>>>>>bruce
>>>>
>>>>> 7      0.19  -0.50   1. c7 Kb7 2. c8=Q+ Kxc8 3. Kh7 Kb7
>>>>>                      4. Kh6 Kc6 5. Kxh5
>>>>> 7->    0.21  -0.50   1. c7 Kb7 2. c8=Q+ Kxc8 3. Kh7 Kb7
>>>>>                      4. Kh6 Kc6 5. Kxh5
>>>>
>>>>>Crafty never thinks white is winning in this position.
>>>>
>>>>It should think black is winning, because black's pawn can't be stopped, but
>>>>white's can.  I snipped out a lot of the other lines here, but does anyone else
>>>>think that the line I kept is completely ridiculous?
>>>>
>>>>Bob, what the heck is crafty doing there?
>>>>
>>>>bruce
>>>
>>>There are several possible issues here.  My PV may well be silly on the end.
>>>When I get a hash hit, with an EXACT score, the PV is obviously cut short at
>>>that point.  Later, I try to probe the hash table to add more moves to the
>>>end.  And on occasion, those moves might not make any sense, and might not
>>>even be part of the set of moves that leads to the score it gave...
>>>
>>>Here is a non-egtb output from crafty (400mhz machine, one cpu):
>>>
>>>              time surplus   0.00  time limit 30.00 (3:00)
>>>         nss  depth   time  score   variation (1)
>>>                1     0.00  -3.50   1. Kg8
>>>                1->   0.00  -3.50   1. Kg8
>>>                2     0.00     --   1. Kg8
>>>                2     0.00  -3.91   1. Kg8 h4
>>>                2     0.00     ++   1. c7!!
>>>                2     0.00   0.00   1. c7 Kb7 2. c8=Q+ Kxc8
>>
>>[snip]
>>
>>Bob.. how can you justify zero score here...?
>
>
>Good question...  I am looking...  There is one potential explanation for old
>crafty's...  someone sent me a change to the rook pawn + wrong bishop code
>that worked in every case except one...  no bishops and the opponent has enough
>pawns to win, while it only had a rook pawn that couldn't promote.  The change
>would say "draw" which was wrong.  I "thought" this was fixed.  In looking at
>the position, I might have either lost the fix, or else my fix had a hole I
>didn't notice.
>
>More in a little while...
>
>OK...  my "fix" got lost.  Not sure how... probably meant to copy from my
>notebook (with fix) to my quad xeon, but must have done it backward losing
>the fix.
>
>I will re-do the fix and rerun the test.  It is nonsense at present...


Here is more reasonable output:

         nss  depth   time  score   variation (1)
                1     0.00  -3.50   1. Kg8
                1->   0.01  -3.50   1. Kg8
                2     0.02     --   1. Kg8
                2     0.03  -3.91   1. Kg8 h4
                2     0.04     ++   1. c7!!
                2     0.05  -3.17   1. c7 Kb7 2. Kg8
                2->   0.06  -3.17   1. c7 Kb7 2. Kg8
                3     0.06     --   1. c7
                3     0.07  -5.63   1. c7 Kb7 2. Kg7 Kxc7
                3     0.08     ++   1. Kg8!!
                3     0.09  -3.58   1. Kg8 h4 2. c7 Kb7
                3     0.10  -3.41   1. Kg7 h4 2. Kf6
                3->   0.12  -3.41   1. Kg7 h4 2. Kf6
                4     0.13     ++   1. Kg7!!
                4     0.16  -2.97   1. Kh7 Kb6 2. c7 Kb7 3. Kg6
                4->   0.17  -2.97   1. Kh7 Kb6 2. c7 Kb7 3. Kg6
                5     0.18     --   1. Kh7
                5     0.19  -4.21   1. Kh7 h4 2. Kg6 h3 3. c7 Kb7
                5     0.20  -4.14   1. Kg8 h4 2. Kf7 h3 3. Ke6
                5     0.21  -3.91   1. Kg7 h4 2. Kf6 h3 3. c7 Kb7
                5->   0.22  -3.91   1. Kg7 h4 2. Kf6 h3 3. c7 Kb7
                6     0.22     ++   1. Kg7!!
                6     0.23  -3.08   1. Kg7 h4 2. Kg6 Kb6 3. c7 Kb7 4. Kf6
                6->   0.23  -3.08   1. Kg7 h4 2. Kg6 Kb6 3. c7 Kb7 4. Kf6
                7     0.23     --   1. Kg7
                7     0.24  -3.74   1. Kg7 h4 2. Kf6 Kb6 3. Ke5 h3 4. Kd6
                7->   0.25  -3.74   1. Kg7 h4 2. Kf6 Kb6 3. Ke5 h3 4. Kd6
                8     0.26  -3.94   1. Kg7 h4 2. Kf6 h3 3. Ke6 Kb6 4. Kd7
                                    Ka6
                8->   0.27  -3.94   1. Kg7 h4 2. Kf6 h3 3. Ke6 Kb6 4. Kd7
                                    Ka6
                9     0.32  -3.81   1. Kg7 h4 2. Kf6 Kb6 3. Ke5 h3 4. Kd6
                                    Ka6 5. c7 Kb7
                9->   0.34  -3.81   1. Kg7 h4 2. Kf6 Kb6 3. Ke5 h3 4. Kd6
                                    Ka6 5. c7 Kb7
               10     0.36     ++   1. Kg7!!
               10     0.46  -3.21   1. Kg7 h4 2. Kf6 Kb6 3. Ke5 h3 4. Kd6
                                    Ka6 5. c7 Kb7 6. Kd7
               10->   0.57  -3.21   1. Kg7 h4 2. Kf6 Kb6 3. Ke5 h3 4. Kd6
                                    Ka6 5. c7 Kb7 6. Kd7
               11     0.61     ++   1. Kg7!!
               11     0.64   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1
               11->   0.65   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1
               12     0.72   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Kf8
               12->   0.75   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Kf8
               13     0.84   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7
               13->   0.86   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7
               14     0.97   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5
               14->   1.00   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5
               15     1.19   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5 10. Qe8
               15->   1.22   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5 10. Qe8
               16     1.48   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5 10. Qe8
                                    Qxe8+ 11. Kxe8
               16->   1.51   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5 10. Qe8
                                    Qxe8+ 11. Kxe8
               17     1.88   0.00   1. Kg7 h4 2. Kf6 h3 3. Ke6 h2 4. c7
                                    Kb7 5. Kd7 h1=Q 6. c8=Q+ Kb6 7. Ke8
                                    Qa1 8. Qd7 Qh8+ 9. Kf7 Ka5 10. Qe8
                                    Qxe8+ 11. Kxe8 Ka4



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