Author: Bernhard Bauer
Date: 06:10:41 01/13/00
Go up one level in this thread
On January 12, 2000 at 14:35:40, blass uri wrote:
>On January 12, 2000 at 13:41:29, m.d.hurd wrote:
>
>>On January 12, 2000 at 12:09:08, John Merlino wrote:
>>
>>>On January 11, 2000 at 22:15:50, Imran Hendley wrote:
>>>
>>>>On January 11, 2000 at 20:06:00, John Merlino wrote:
>>>>
>>>>>On January 11, 2000 at 03:11:42, m.d.hurd wrote:
>>>>>
>>>>>>On January 11, 2000 at 03:07:19, m.d.hurd wrote:
>>>>>>Correction :
>>>>>>
>>>>>>Fritz 6 solves this in seconds and keeps announcing the mate up to where it
>>>>>>promotes to a knight then draws by three fold repitition.
>>>>>>
>>>>>>
>>>>>>Start position
>>>>>>
>>>>>>[D] 8/8/8/2p5/1pp5/brpp4/1pprp2P/qnkbK3 w - - 0 1
>>>>>>
>>>>>>Regards
>>>>>>
>>>>>>Mike
>>>>>
>>>>>Chessmaster falls into the same trap as Fritz (et. al.). It announced mate in 15
>>>>>in 8 seconds (on a PII-450), and proceeded to promote to a queen for a 3-fold
>>>>>draw.
>>>>>
>>>>>But, if I take it past the knight promotion, it DOES work out the mate in 9 from
>>>>>there.
>>>>>
>>>>>jm
>>>>
>>>>I don't see the logic behind this. When it announces mate does it see the knight
>>>>promotion? If so why does it promote to a Queen? And if when it announces mate
>>>>it sees a Queen promotion, how can this be, because there is obviously no mate
>>>>with a Queen. Do you know why this happens?
>>>
>>>I have no idea why it happens. It does appear to defy logic. But there must be
>>>SOME programmatic reason for it, since Fritz appears to do its own version of
>>>the same thing (announce mate, promote to knight, draw by 3-fold).
>>>
>>>jm
>>
>>And not just Fritz 6, if you take the position after the pawn has promoted to a
>>Knight, neither Fritz 6 or 5.32 or Hiarcs 7.32 or Crafty 17.4 find the mate.
>>Doctor 3 does and also comet b10. So some solve it and some do not, maybe
>>someone else knows the answer why it should be so difficult.
>>
>>Mike
>
>The logic is that some programs do assumptions that king and knight with no more
>pieces cannot win.
>
>Fritz is alsoa root processor so it does this assumption only when white has
>only king and knight in the root position.
>
>Uri
This position, like many others is again a null move issue.
If you modify one line in crafty 16.05 you will get the following output:
27-> 20.92 0.00 1. h4 Qa2 2. h5 Qa1 3. h6 Qa2 4. h7
Qa1 5. h8=Q Qa2 6. Qg8 Qa1 7. Qh8
28 35.33 0.00 1. h4 Qa2 2. h5 Qa1 3. h6 Qa2 4. h7
Qa1 5. h8=Q Qa2 6. Qg8 Qa1 7. Qh8
28 36.36 ++ 1. h3!!
28 37.59 Mat15 1. h3 Qa2 2. h4 Qa1 3. h5 Qa2 4. h6
Qa1 5. h7 Qa2 6. h8=N Qa1 7. Nf7 Qa2
8. Nd6 Qa1 9. Ne4 Qa2 10. Nxc5 Qa1
11. Nd7 Qa2 12. Nb6 Qa1 13. Nxc4 Qa2
14. Na5 Qa1 15. Nxb3#
(2) 28-> 37.61 Mat15 1. h3 Qa2 2. h4 Qa1 3. h5 Qa2 4. h6
Qa1 5. h7 Qa2 6. h8=N Qa1 7. Nf7 Qa2
8. Nd6 Qa1 9. Ne4 Qa2 10. Nxc5 Qa1
11. Nd7 Qa2 12. Nb6 Qa1 13. Nxc4 Qa2
14. Na5 Qa1 15. Nxb3#
29 48.25 Mat15 1. h3 Qa2 2. h4 Qa1 3. h5 Qa2 4. h6
Qa1 5. h7 Qa2 6. h8=N Qa1 7. Nf7 Qa2
8. Nd6 Qa1 9. Ne4 Qa2 10. Nxc5 Qa1
11. Nd7 Qa2 12. Nb6 Qa1 13. Nxc4 Qa2
14. Na5 Qa1 15. Nxb3#
(2) 29-> 1:14 Mat15 1. h3 Qa2 2. h4 Qa1 3. h5 Qa2 4. h6
Qa1 5. h7 Qa2 6. h8=N Qa1 7. Nf7 Qa2
8. Nd6 Qa1 9. Ne4 Qa2 10. Nxc5 Qa1
11. Nd7 Qa2 12. Nb6 Qa1 13. Nxc4 Qa2
14. Na5 Qa1 15. Nxb3#
time=1:14 cpu=225% mat=-35 n=47875266 fh=99% nps=643138
ext-> checks=1252940 recaps=45118 pawns=91319 1rep=87690 thrt:296
predicted=0 nodes=47875266 evals=571
endgame tablebase-> probes done=0 successful=0
hashing-> trans/ref=80% pawn=99% used=90%
SMP-> split=6014 stop=22 data=12/64 cpu=2:47 elap=1:14
mate in 15 moves.
Kind regards
Bernhard
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.