Author: Robert Hyatt
Date: 09:17:28 03/11/99
Go up one level in this thread
On March 11, 1999 at 02:03:04, Peter Kappler wrote:
>On March 10, 1999 at 23:08:47, blass uri wrote:
>
>>
>>On March 10, 1999 at 22:59:37, Robert Hyatt wrote:
>>
>>>On March 10, 1999 at 22:49:00, Robert Hyatt wrote:
>>>
>>>>On March 10, 1999 at 21:54:51, blass uri wrote:
>>>>
>>>>>
>>>>>On March 10, 1999 at 21:16:33, Robert Hyatt wrote:
>>>>>
>>>>>>On March 10, 1999 at 02:33:14, Peter Kappler wrote:
>>>>>>
>>>>>>>
>>>>>>>8/8/4kpp1/3p1b2/p6P/2B5/6P1/6K1 b - - bm Bh3; id "Topalov-Shirov Linares 98";
>>>>>>>
>>>>>>>
>>>>>>>Does everybody remember this game? It's from last year's Linares tournament,
>>>>>>>where Shirov played a shocking bishop sacrifice in the endgame and won
>>>>>>>brilliantly. I believe that post-mortem analysis proved it was the only way to
>>>>>>>win. (Please correct me if this is wrong)
>>>>>>>
>>>>>>>I watched this game live on ICC with dozens of others, and we were all quite
>>>>>>>impressed with Shirov's powers of calculation.
>>>>>>>
>>>>>>>This *should* be an extremely difficult problem for computers - but I'm sure
>>>>>>>somebody will tell me that Hiarcs or some other commercial program can solve it
>>>>>>>in 10 seconds.
>>>>>>>
>>>>>>>Just curious...
>>>>>>>
>>>>>>>--Peter
>>>>>>
>>>>>>
>>>>>>I ran this two ways.. First from the original position to see what crafty would
>>>>>>play with no 'urging' by me:
>>>>>>
>>>>>> 12-> 6.37 2.61 1. ... a3 2. Kf2 Bc2 3. g4 Bd1 4. h5
>>>>>> gxh5 5. gxh5 Bxh5 6. Ke3 a2 7. Kd4
>>>>>> Bd1 8. Ba1 f5
>>>>>> 13 11.78 2.62 1. ... a3 2. Kf2 Bc2 3. g4 Bd1 4. h5
>>>>>> gxh5 5. gxh5 Bxh5 6. Ke3 a2 7. Bb2
>>>>>> Bg6 8. Kd4 Be4 9. Ba1
>>>>>> 13-> 13.87 2.62 1. ... a3 2. Kf2 Bc2 3. g4 Bd1 4. h5
>>>>>> gxh5 5. gxh5 Bxh5 6. Ke3 a2 7. Bb2
>>>>>> Bg6 8. Kd4 Be4 9. Ba1
>>>>>> 14 34.53 2.46 1. ... a3 2. Kf2 Bc2 3. Ba1 Kf5 4.
>>>>>> Ke3 Be4 5. g3 a2 6. Kf2 Bc2
>>>>>> 14-> 45.46 2.46 1. ... a3 2. Kf2 Bc2 3. Ba1 Kf5 4.
>>>>>> Ke3 Be4 5. g3 a2 6. Kf2 Bc2
>>>>>> 15 1:08 2.46 1. ... a3 2. Kf2 Bc2 3. Ba1 Kf5 4.
>>>>>> Ke3 Be4 5. g3 a2 6. Kf2 Bc2
>>>>>> 15-> 1:24 2.46 1. ... a3 2. Kf2 Bc2 3. Ba1 Kf5 4.
>>>>>> Ke3 Be4 5. g3 a2 6. Kf2 Bc2
>>>>>> 16 2:55 2.37 1. ... a3 2. Kf2 Bc2 3. Ke3 a2 4. g3
>>>>>> Kf5 5. Kd4 Be4 6. Kc5 Kg4 7. Bxf6 Kxg3
>>>>>> 8. Kd6 Kg4
>>>>>> 16-> 3:59 2.37 1. ... a3 2. Kf2 Bc2 3. Ke3 a2 4. g3
>>>>>> Kf5 5. Kd4 Be4 6. Kc5 Kg4 7. Bxf6 Kxg3
>>>>>> 8. Kd6 Kg4
>>>>>> 17 8:25 2.42 1. ... a3 2. Kf2 a2 3. Ke2 Be4 4. Kf2
>>>>>> Kf5 5. g3 Bb1 6. Ke3 Bc2 7. Kd4 Be4
>>>>>> 8. Kc5 Kg4 9. Bxf6
>>>>>>
>>>>>>
>>>>>>so it likes a3 thru any depth it might get in a real tournament setting.
>>>>>>
>>>>>>
>>>>>>I then played Bh3 and let it search for white:
>>>>>>
>>>>>> 16-> 49.18 0.56 2. gxh3 Kf5 3. Kf2 Kf4 4. Bxf6 a3 5.
>>>>>> Bc3 Ke4 6. Ba1 Kf4 7. Bh8
>>>>>> 17 1:14 0.68 2. gxh3 Kf5 3. Kf2 Kf4 4. Bxf6 a3 5.
>>>>>> Bc3 Ke4 6. Ke2 Kf4 7. Kd3 Kg3 8. Bf6
>>>>>> a2 9. Kc2 Kf4 10. Kb3 Kf5
>>>>>> 17-> 1:22 0.68 2. gxh3 Kf5 3. Kf2 Kf4 4. Bxf6 a3 5.
>>>>>> Bc3 Ke4 6. Ke2 Kf4 7. Kd3 Kg3 8. Bf6
>>>>>> a2 9. Kc2 Kf4 10. Kb3 Kf5
>>>>>> 18 1:56 -- 2. gxh3
>>>>>> 18 2:39 0.00 2. gxh3 Kf5 3. Kf2 Ke4 4. Bxf6 a3 5.
>>>>>> h5 gxh5 6. Ba1 d4 7. Ke2 h4 8. Kd2
>>>>>> Kf4 9. Bxd4 Kg3 10. Bc3 Kxh3
>>>>>> 18-> 3:26 0.00 2. gxh3 Kf5 3. Kf2 Ke4 4. Bxf6 a3 5.
>>>>>> h5 gxh5 6. Ba1 d4 7. Ke2 h4 8. Kd2
>>>>>> Kf4 9. Bxd4 Kg3 10. Bc3 Kxh3
>>>>>> 19 4:37 0.00 2. gxh3 Kf5 3. Kf2 Ke4 4. Bxf6 a3 5.
>>>>>> h5 gxh5 6. Ba1 d4 7. Ke2 h4 8. Kd2
>>>>>> Kf4 9. Bxd4 Kg3 10. Bc3 Kxh3
>>>>>> 19-> 5:24 0.00 2. gxh3 Kf5 3. Kf2 Ke4 4. Bxf6 a3 5.
>>>>>> h5 gxh5 6. Ba1 d4 7. Ke2 h4 8. Kd2
>>>>>> Kf4 9. Bxd4 Kg3 10. Bc3 Kxh3
>>>>>>
>>>>>>which is right interesting, because notice this runs into the 5 piece
>>>>>>tablebases and says _draw_.
>>>>>>
>>>>>>question is, now, does Bh3 really make sense? This seems to say "no".
>>>>>>
>>>>>>interesting...
>>>>>Did you let crafty to play against itself.
>>>>>after 2.gxh3 Kf5 3.Kf2 Ke4 4.Bxf6
>>>>>crafty16.5 as an engine for Junior5(no tablebases) prefers 4...d4 with
>>>>>evaluation -6.01 at depth 18 and -6.02 at depth 19
>>>>>
>>>>>I believe that crafty needs more time to see the win after Bh3.
>>>>>
>>>>>I do not remember the game but I remember that I analyzed it with a computer and
>>>>>did not see a draw for white.
>>>>>
>>>>>Uri
>>>>
>>>>
>>>>I will check deeper.. but note that after Bh3, it reaches the endgame databases
>>>>and with white on move, it claims white can force a dead draw. I don't see any
>>>>reason it would change to let black do more, after forcing a path to a tablebase
>>>>draw...
>>>>
>>>>And note that crafty is using _all_ the 5 piece files we have, which covers
>>>>a lot of territory. But I'll let it run a ways longer forcing the 'drawing'
>>>>white move first to see if black can 'improve'.
>>>
>>>
>>>Still says 'draw'... but there is a minor problem here, in that crafty believes
>>>black is losing and so would choose a draw given the chance. And there is no
>>>way to solve this.
>>>
>>>What I might propose is that we simply play this out... I'll run crafty on the
>>>white side, you play the black side. And let's see if it is winnable against
>>>the database 'monster'. I'd suggest we start after Bh3 gxh3 (assuming gxh3 is
>>>the best move for now, since Crafty says that leads to a tablebase draw).
>>>
>>>It alternates between Kf5 and f5 as black's next move, but I'll leave that to
>>>you to choose if you want to try this. Seems like an interesting thing to do
>>>of course. I'd love to be able to write that his Bh3 was no more than a draw
>>>after his occasional comments about 'no computer will ever solve this position'
>>>only to have one find the right move in minutes. :)
>>>
>>>I have gone thru 21 plies with black's second move and crafty still says Kf5,
>>>score=0.00
>>>
>>>Bob
>>
>>After 1...Bh3 2.gxh3 I play 2...Kf5 and if 3.Kf2 I play Ke4 and if 4.Bxf6 I play
>>4...d4
>>
>>Uri
>
>
>That is exactly how the game continued...
>
>47. ... Bh3!!
>48. gxh3 Kf5
>49. Kf2 Ke4
>50. Bxf6 d4
>51. Be7 Kd3
>52. Bc5 Kc4
>53. Be7 Kb3
>
>and White resigned.
>
>According to Seirawan's notes in Inside Chess, Black will play 54...Kc2 and
>queen one of the pawns.
>
>So, can Crafty improve upon Topalov's play?
>
>--Peter
I don't know... this is the problem here... white appears to be winning
to a normal 'evaluation'. Which means that when crafty searches, it looks
for ways for white to win, and assumes black will do anything it can to avoid
these 'winning' positions which translates into drawing if possible.
That was why I said that I am not anywhere near sure that this is drawn. About
all my analysis has shown so far is that black can certainly force a draw if it
wants. And once I got deep enough down the main line, it certainly seems that
black wins this easily... IE after the Kf2/Ke4 moves, Bxf6 fails low at ply=19,
to -6.24. Which means that this needs 25 plies from the original position to
play Bh3.
I will attach crafty's output, where it won't play Bxf6 (-6.xx score) but
instead would play Bb4. 15 5.17 0.00 4. Bxf6 a3 5. Ba1 a2
6. Ke2 Kf4 7.
Kf2 Ke4
15-> 7.62 0.00 4. Bxf6 a3 5. Ba1 a2 6. Ke2 Kf4 7.
Kf2 Ke4
16 23.69 -- 4. Bxf6
16 31.75 -0.11 4. Bxf6 d4 5. h5 gxh5 6. Be7 Kd3 7.
Bc5 Kc4 8. Be7 Kb3 9. Ke1 a3 10. Bc5
d3 11. Kd2 a2 12. Bd4
16-> 43.78 -0.11 4. Bxf6 d4 5. h5 gxh5 6. Be7 Kd3 7.
Bc5 Kc4 8. Be7 Kb3 9. Ke1 a3 10. Bc5
d3 11. Kd2 a2 12. Bd4
17 1:08 -0.07 4. Bxf6 d4 5. Be7 Kd3 6. Bc5 Kc4 7.
Bd6 Kc3 8. h5 gxh5 9. Be5 a3 10. Kf3
Kc4 11. Ke4 d3 12. Kf5 d2 <HT>
17-> 1:20 -0.07 4. Bxf6 d4 5. Be7 Kd3 6. Bc5 Kc4 7.
Bd6 Kc3 8. h5 gxh5 9. Be5 a3 10. Kf3
Kc4 11. Ke4 d3 12. Kf5 d2 <HT>
18 1:24 -- 4. Bxf6
18 1:50 ++ 4. Bxf6!!
18-> 2:24 -0.08 4. Bxf6 d4 5. Be7 Kd3 6. Bc5 Kc4 7.
Bd6 Kc3 8. h5 gxh5 9. Be5 a3 10. Kf3
Kc4 11. Ke4 d3 12. Kf5 d2 <HT>
19 2:32 -- 4. Bxf6
19 3:12 -6.24 4. Bxf6 d4 5. Be7 Kd3 6. Bb4 Kc2 7.
Ke2 d3+ 8. Ke3 a3 9. Bxa3 d2 10. Be7
d1=Q 11. Bg5 Qd3+ 12. Kf4 Qxh3 <HT>
19 4:35 ++ 4. Bb4!!
19 12:15 -2.36 4. Bb4 d4 5. h5 gxh5 6. Ke2 f5 7. Bd6
d3+ 8. Kf2 f4 9. Bf8 f3 10. Ke1 Kd4
11. Bg7+ Kc4 12. Bb2 Kb3 <HT>
19-> 14:52 -2.36 4. Bb4 d4 5. h5 gxh5 6. Ke2 f5 7. Bd6
d3+ 8. Kf2 f4 9. Bf8 f3 10. Ke1 Kd4
11. Bg7+ Kc4 12. Bb2 Kb3 <HT>
That is a different move, to be sure...
I let crafty play that and followed with d4 as suggested... this is the
next result:
20-> 25:19 -2.38 5. Ke1 d3 6. h5 gxh5 7. Kd1 f5 8. Bc5
f4 9. Kd2 f3 10. Ke1 Kd5 11. Bf8 Kc4
12. h4 Kc3 13. Bc5 Kc2 14. Bb4 Kc1
21 29:04 -2.51 5. Ke1 d3 6. h5 gxh5 7. Kd1 f5 8. Bc5
f4 9. Kd2 f3 10. Ke1 Kd5 11. Ba3 Kc4
12. Bb2 Kb3 13. Bd4 Kc2 14. Be3 a3
15. Kf2
21-> 36:32 -2.51 5. Ke1 d3 6. h5 gxh5 7. Kd1 f5 8. Bc5
f4 9. Kd2 f3 10. Ke1 Kd5 11. Ba3 Kc4
12. Bb2 Kb3 13. Bd4 Kc2 14. Be3 a3
15. Kf2
22 37:59 -- 5. Ke1
22 45:57 -2.91 5. Ke1 d3 6. h5 gxh5 7. Kd1 f5 8. Bc5
f4 9. Kd2 f3 10. Ke1 Kd5 11. Be7 Ke5
12. h4 Kf4 13. Bf8 Kg3 14. Bd6+ Kxh4
15. Be5 a3 16. Kd2
22-> 60:22 -2.91 5. Ke1 d3 6. h5 gxh5 7. Kd1 f5 8. Bc5
f4 9. Kd2 f3 10. Ke1 Kd5 11. Be7 Ke5
12. h4 Kf4 13. Bf8 Kg3 14. Bd6+ Kxh4
15. Be5 a3 16. Kd2
looking bad, but not nearly so bad as simply rolling belly-up with Bxf6 it
seems...
Bob
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.