Author: Dieter Buerssner
Date: 20:37:06 03/17/01
Go up one level in this thread
On March 17, 2001 at 21:18:35, Robert Hyatt 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.
>I would suspect a bug.
That may be the case. And I even suspected this first. But I looked more
carefully in between. To me it still looks, that at first sight this position
may seem easier to a program, than after a deeper look. Especially 2. Qe7+ does
not seem to win fast.
>I ran this and crafty sees +8 instantly and hangs on to
>that type of score forever.
I actually also had checked Crafty 17.13, and it also showed strange behaviour.
I Just rechecked with the newest version. It does not really hang at +8. It gets
one fail high after the other for 1...Kg7, interestingly allways with a
difference of 0.39, and with exactly the same PV as the previous iteration:
8-> 1.33 8.05 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. d8=Q Qxf2+ 7.
Kh1 Kf5 <HT>
9 2.30 ++ 1. ... Kg7!!
9-> 4.23 7.66 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. d8=Q Qxf2+ 7.
Kh1 Kf5 8. Qf8+ <HT>
10 6.63 ++ 1. ... Kg7!!
10-> 11.98 7.27 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. d8=Q Qxf2+ 7.
Kh1 Kf5 8. Qf8+ <HT>
11 18.12 7.61 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. Kg1 g4 7. d8=Q
Qxd8 8. Qxd8 gxh3
11-> 18.27 7.61 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. Kg1 g4 7. d8=Q
Qxd8 8. Qxd8 gxh3
12 1:02 ++ 1. ... Kg7!!
12-> 1:42 7.22 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. Kg1 g4 7. d8=Q
Qxd8 8. Qxd8 gxh3
13 2:49 ++ 1. ... Kg7!!
13-> 7:54 6.83 1. ... Kg7 2. Qe7+ Kg6 3. Qc7 Qb1 4.
d7 Qe4+ 5. Kh2 Qd4 6. Kg1 g4 7. d8=Q
Qxd8 8. Qxd8 gxh3
In 20 minutes nothing new came. (This is a rather solow computer)
After doing 1...Kg7:
8-> 2.73 7.61 2. Qe7+ Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. Kg1 g4 7. d8=Q Qxd8 8. Qxd8
gxh3
9 4.06 -- 2. Qe7+
9 14.30 0.97 2. Qe7+ Kg6 3. d7 Qb7+ 4. f3 Qb2+ 5.
Kg3 Qb8+ 6. Kf2 Qb2+ 7. Ke3 Qc3+ 8.
Ke2 Qc2+ 9. Kf1 Qd1+ 10. Kg2 Qd2+ 11.
Kg3
9 29.16 0.98 2. Qd7+ Kg6 3. h4 gxh4 4. Qe8+ Kg7
5. Qe7+ Kg6 6. d7 Qc6+ 7. Kh2 Qc7+
8. Kh3 Qc3+ 9. Kxh4 Qd4+ 10. Kg3
9-> 40.21 0.98 2. Qd7+ Kg6 3. h4 gxh4 4. Qe8+ Kg7
5. Qe7+ Kg6 6. d7 Qc6+ 7. Kh2 Qc7+
8. Kh3 Qc3+ 9. Kxh4 Qd4+ 10. Kg3
10 53.25 1.19 2. Qd7+ Kg6 3. h4 gxh4 4. Qe8+ Kf6
5. d7 Qc6+ 6. Kh2 Qd6+ 7. Kh3 Qa3+
8. Kxh4 Qb4+ 9. Kg3 Qd6+ 10. f4 Qd3+
11. Kg4
10-> 1:03 1.19 2. Qd7+ Kg6 3. h4 gxh4 4. Qe8+ Kf6
5. d7 Qc6+ 6. Kh2 Qd6+ 7. Kh3 Qa3+
8. Kxh4 Qb4+ 9. Kg3 Qd6+ 10. f4 Qd3+
11. Kg4
11 1:23 ++ 2. Qd7+!!
11 3:10 4.21 2. Qd7+ Kg6 3. h4 Qb4 4. Qe6+ Kh7 5.
d7 Qb7+ 6. Kh2 Qb8+ 7. Kh3 g4+ 8. Kxg4
h5+ 9. Kxh5 Qb5+ 10. Kg4 Qa4+ <HT>
11-> 3:19 4.21 2. Qd7+ Kg6 3. h4 Qb4 4. Qe6+ Kh7 5.
d7 Qb7+ 6. Kh2 Qb8+ 7. Kh3 g4+ 8. Kxg4
h5+ 9. Kxh5 Qb5+ 10. Kg4 Qa4+ <HT>
So eventually a winning score is seen, for a different move. If I do 2. Qe7+, as
suggested for a very long time above:
7-> 0.60 8.05 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. d8=Q Qxf2+ 7. Kh1 Kf5
8 1.24 ++ 2. ... Kg6!!
8-> 1.44 7.66 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. d8=Q Qxf2+ 7. Kh1 Kf5
9 4.05 ++ 2. ... Kg6!!
9-> 4.38 7.27 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. d8=Q Qxf2+ 7. Kh1 Kf5
10 12.47 7.61 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. Kg1 g4 7. d8=Q Qxd8 8. Qxd8
gxh3
10-> 12.68 7.61 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. Kg1 g4 7. d8=Q Qxd8 8. Qxd8
gxh3
11 13.33 -- 2. ... Kg6
11 55.43 7.61 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. Kg1 Qd1+ 7. Kg2 Qd5+ 8.
Kg3 Qd3+ 9. Kh2 Qd4 <HT>
11-> 55.81 7.61 2. ... Kg6 3. Qc7 Qb1 4. d7 Qe4+ 5.
Kh2 Qd4 6. Kg1 Qd1+ 7. Kg2 Qd5+ 8.
Kg3 Qd3+ 9. Kh2 Qd4 <HT>
12 57.30 -- 2. ... Kg6
12 2:56 ++ 2. ... Kg6!!
12 17:16 1.58 2. ... Kg6 3. Qc7 Qb1 4. Qc6 Kf6 5.
Qxa6 Qe4+ 6. f3 Qe3 7. Qa1+ Ke6 8.
Qd1 Kd7 9. Qd5
12-> 17:17 1.58 2. ... Kg6 3. Qc7 Qb1 4. Qc6 Kf6 5.
Qxa6 Qe4+ 6. f3 Qe3 7. Qa1+ Ke6 8.
Qd1 Kd7 9. Qd5
So I think, all in all, this is not much different than the behaviour of Yace
above. I could even argue, that Yace has seen earlier, that 2. Qe7+ is not
winning easily. To compare scores, you might want to take into account, that
Yace uses a misleading material score of 0.8 for pawns.
I also tried with Shredder 5. It also gets several fail-highs for 1...Kg7:
(Note, this is German notation, so you have to substitute D with Q)
7.01 0:01 -7.39 1...Kg7 2.De7+ Kg6 3.Dc7 Db1 4.d7 De4+ 5.Kh2 Dd4 6.d8D
Dxf2+ 7.Kh1 (66.393) 42.1
8.01 0:02 -7.14++ 1...Kg7 2.De7+ Kg6 3.Dc7 Db1 4.d7 De4+ 5.Kh2 Dd4 6.Dc6+
Kg7 7.Dxh6+ Kxh6 (121.865) 57.0
8.01 0:02 -7.18 1...Kg7 2.De7+ Kg6 3.Dc7 Db3 4.d7 a5 5.d8D Kf5 6.Dxa5+ Kf4
(129.727) 58.5
9.01 0:03 -6.93++ 1...Kg7 2.De7+ Kg6 3.Dc7 Db3 4.d7 Dd5+ 5.Kh2 Dd4 6.Dc6+
Kg7 7.Da4 Dxa4 (251.257) 74.8
9.01 0:03 -6.93 1...Kg7 2.De7+ Kg6 3.Dc7 Db3 4.d7 Db1 5.d8D De4+ 6.Kf1 Dd3+
7.Dxd3+ Kf6 8.Dxa6+ Kf5 9.Dxh6 (262.085) 75.5
10.01 0:05 -6.68++ 1...Kg7 2.De7+ Kg6 3.Dc7 Db3 4.d7 Dd5+ 5.Kh2 Dd4 6.Db6+
Dxb6 7.f3 a5 (528.676) 92.0
10.01 0:05 -6.68 1...Kg7 2.De7+ Kg6 3.Dc7 Db1 4.d7 g4 5.d8D De4+ 6.Kf1 Db1+
7.Ke2 Dc2+ 8.Dxc2+ Kg7 (546.470) 92.4
11.01 0:10 -6.68 1...Kg7 2.De7+ Kg6 3.Dc7 Db1 4.d7 De4+ 5.Kh2 Dd4 6.Kg2 g4
7.d8D Dh8 (1.027.065) 98.4
12.01 0:28 -6.68 1...Kg7 2.De7+ Kg6 3.Dc7 Db1 4.d7 De4+ 5.Kh2 Dd4 6.Kg2 g4
7.d8D Dh8 (2.895.675) 102.7
13.01 4:30 -6.68 1...Kg7 2.De7+ Kg6 3.Dc7 Db1 4.d7 De4+ 5.Kh2 Dd4 6.Kg2
(25.606.939) 94.7
[Doing the suggested moves rather fast on the board, after 1...Kg7]
12.01 0:00 +6.68 2.De7+ Kg6 3.Dc7 Db1 4.d7 De4+ 5.Kh2 Dd4 6.Kg1 Dd1+ 7.Kg2
Dd5+ 8.Kh2 g4 9.d8D Kh5 (351) 3.8
[After 2. Qe7+]
11.01 0:01 -6.68 2...Kg6 3.Dc7 Db1 (119.173) 115.2
Bester Zug: Kg7-g6 Zeit: 0:06.875 min K/s: 112.979 Knoten: 774.927 TB: 77
11.01 0:00 +6.68 3.Dc7 (3.560) 21.8
12.01 0:06 +6.68 3.Dc7 (676.294) 109.4
Bester Zug: Dd7-c7 Zeit: 0:35.180 min K/s: 108.657 Knoten: 3.821.267 TB: 446
8.01 0:02 -1.63++ 3...Dd4 4.d7 Dd5+ 5.Kh2 Dd4 6.Kg3 Dd3+ 7.Kh2 Dd4 8.Kg3
(197.112) 97.8
8.01 0:02 -1.43 3...Dd4 4.d7 Dd5+ 5.Kh2 Dd4 6.Kg3 Dd3+ 7.Kh2 Dd4 8.Kg3
(262.446) 99.2
9.01 0:05 -1.18++ 3...Dd4 4.d7 Dd5+ 5.Kh2 Dd4 6.Dc2+ Kf6 7.Kh1 (503.476)
98.4
9.01 0:08 -0.78 3...Dd4 4.d7 Dd5+ 5.Kh2 Dd4 6.Dc6+ Kf7 7.Kg1 Dd1+ 8.Kg2 a5
9.Dxh6 Dd5+ 10.Kf1 Dxd7 (882.915) 98.4
10.01 0:18 -0.77 3...Dd4 4.d7 Dd5+ 5.Kh2 Dd4 6.Dc6+ Kf7 7.Kg2 Ke7 8.d8L+
Kxd8 9.Da8+ Kd7 10.Db7+ Kd6 11.Dxa6+ Kc5 12.Da3+ Kd5 13.Db3+ Kd6 14.Db8+ Kc5
(1.756.735) 96.1
And we are again back to a rather drawish score.
> I just fixed a major bug in repetition code about
>2 versions back, so bugs _can_ happen to anybody. :)
I don't know about anybody, they certainly happen to me :-(
Regards,
Dieter "Or do I have a buggy computer?" Bürßner
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