Author: Uri Blass
Date: 11:02:42 03/17/01
Go up one level in this thread
On March 17, 2001 at 12:20:37, Ernst Walet wrote:
>On March 17, 2001 at 10:22:39, Dieter Buerssner wrote:
>
>>On March 17, 2001 at 06:13:23, Christian Koch wrote:
>>
>>> 8/8/pq1PQ1kp/6p1/8/7P/5PK1/8 b - -
>>>
>>>This is the evaluation of Gandalf. Gandalf needs much time to see that he is
>>>totally lost. Other programms only need seconds to see it.
>>>I think Gandalfs endgame should be improved to play at a high level.
>>
>>I tried this position with Yace. Something strange happened:
>>
>> 51305 0.702 -0.40 5. 1...Kg7 2.Qe7+ Kg6 3.Qe8+ Kf6 4.Qe7+ Kg6 5.Qe8+
>> Kf6 6.Qe7+ Kg6 {0}
>> 111931 1.638 -0.80 6-- 1...Kg7 2.Qe7+ Kg8 3.d7 Qc6+ 4.Kg3 Qc7+ 5.Kg4
>> Qc6 6.d8=Q+ Qe8 {-921}
>> 137448 1.868 -7.64 6t 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 g4 5.d8=Q
>> Qxh3+ 6.Kg1 {-841}
>> 150310 1.974 -7.64 6. 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 g4 5.d8=Q
>> Qxh3+ 6.Kg1 {-841}
>>
>>Here one could assume, that it really sees fast, that black is lost
>>
>> 186148 2.222 -7.75 7t 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 g4 5.Qd6+ Kg7
>> 6.Qe7+ Kg6 7.Qe4+H Kf7H 8.d8=QH Qxh3+H 9.Kg1H
>> {-841}
>> 191019 2.266 -7.75 7. 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 g4 5.Qd6+ Kg7
>> 6.Qe7+ Kg6 7.Qe4+ Kf7 8.d8=Q Qxh3+ 9.Kg1 {-841}
>> 337668 3.199 -7.78 8t 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 g4 5.Qd6+ Kf7
>> 6.d8=Q Qxh3+ 7.Kg1 {-841}
>> 505552 4.276 -7.78 8. 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 g4 5.Qd6+ Kf7
>> 6.d8=Q Qxh3+ 7.Kg1 {-841}
>>
>>And it kept about the same for another 2 plies. But now:
>>
>> 1666011 12.245 -7.38 9++ 1...Kg7 2.Qe7+ Kg6 3.Qc7 Qb3 4.d7 Qd5+ 5.Kh2
>> Qd4 6.d8=R Qxf2+ 7.Kh1 {-340}
>> 6934801 57.940 -0.40 9t 1...Kg7 2.Qd7+ Kg6 3.h4 {HT}
>> 7368426 1:01.4 -0.40 9. 1...Kg7 2.Qd7+ Kg6 3.h4
>>
>>Huch: we are back at almost drawing score.
>>
>> 8889435 1:13.5 -0.80 10-- 1...Kg7 2.Qd7+ Kg6 3.h4 gxh4 4.Qe8+ Kh7 5.Qe7+
>> Kg6 6.d7 Qc6+ 7.Kh2 Qc7+ 8.Kh3 h5 9.d8=Q a5
>> {-841}
>> 12883052 1:46.1 -1.68 10t 1...Kg7 2.Qd7+ Kg6 3.h4 gxh4 4.Qe8+ Kf6 5.d7
>> Qc6+ 6.Kh2 Qc7+ 7.Kh3 Qc3+ 8.Kxh4 Qc4+ 9.Kg3
>> Qc7+ 10.f4 Qc3+ 11.Kg4 {HT} {0}
>> 13257667 1:48.9 -1.68 10. 1...Kg7 2.Qd7+ Kg6 3.h4 gxh4 4.Qe8+ Kf6 5.d7
>> Qc6+ 6.Kh2 Qc7+ 7.Kh3 Qc3+ 8.Kxh4 Qc4+ 9.Kg3
>> Qc7+ 10.f4 Qc3+ 11.Kg4 {HT} {0}
>> 17090908 2:15.6 -2.08 11-- 1...Kg7 2.Qd7+ Kg6 3.h4 gxh4 4.Qe8+ Kf6 5.d7
>> Qc6+ 6.Kh2 Qc7+ 7.Kh3 Qc3+ 8.Kxh4 Qc4+ 9.Kg3
>> Qc7+ 10.f4 h5 11.d8=Q+ Kf5 {-921}
>> 26447712 3:26.8 -6.50 11t 1...Kg7 2.Qd7+ Kg6 3.h4 Kh5 4.Qe8+ Kxh4 5.Qe3
>> Qxe3 6.fxe3 a5 7.d7 a4 8.d8=Q a3 9.e4 {-841}
>> 26573747 3:27.8 -6.50 11. 1...Kg7 2.Qd7+ Kg6 3.h4 Kh5 4.Qe8+ Kxh4 5.Qe3
>> Qxe3 6.fxe3 a5 7.d7 a4 8.d8=Q a3 9.e4 {-841}
>> 33767907 4:20.6 -6.90 12-- 1...Kg7 2.Qd7+ Kg6 3.h4 Kh5 4.Qe8+ Kxh4 5.Qe3
>> Qxe3 6.fxe3 a5 7.d7 Kh5 8.d8=Q Kg6
>>
>>And after rather long time again at loosing score. I have not investigated the
>>reasons, but perhaps this is more complicated for a chess program, than it looks
>>at first sight.
>>
>>Regards,
>>Dieter
>
>Well, no problem for CM8K, could it be the case that you maybe use incomplete
>sets of tablebases?
No
This position is not about tablebases and I guess it is about perpetual check.
I see that yace and gandalf like Kg7 Qe7+ and only later change their mind to
LKg7 Qd7+
I guess that there is a perpetual check in the line of Kg7 Qe7+ and this is the
reason that they fail low when the main line is Kg7 Qe7+.
I did not analyze the position with my chess programs that are busy in another
position.
Another point is that chessmaster gives a big bonus to unstoppable pawns in
queen endgames when I know some other programs that do not evaluate unstoppable
pawns in queen endgames and it can cause them to see 0.xx score and not 4.xx
score.
Uri
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