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Subject: Re: pawn endgame position

Author: Dusan Dobes

Date: 00:59:26 01/23/01

Go up one level in this thread


On January 23, 2001 at 03:46:15, Dann Corbit wrote:

>On January 23, 2001 at 03:06:53, Dusan Dobes wrote:
>
>>On January 22, 2001 at 15:57:52, Dann Corbit wrote:
>>
>>>>I am interested if "your" engine could resist to play 46.Qe6+ in a blitz game.
>>>>
>>>>[D]6k1/2pq4/5Q2/p2PPP2/1p1P4/8/P6P/7K w
>>>>
>>>>Best wishes,
>>>>Steffen.
>>>>
>>>>[Event "ICS rated blitz match"]
>>>
>>>Phalanx has a time of it:
>>>
>>>[ white, 1 ]
>>>6k1/2pq4/5Q2/p2PPP2/1p1P4/8/P6P/7K w
>>>
>>>6k1/2pq4/5Q2/p2PPP2/1p1P4/8/P6P/7K w
>>>    -> increment adds 1440 s to soft time limit
>>>    -> soft time limit 3154.28 s
>>>    -> hard time limit 41599.9 s
>>>  6    654   112   213089  Qf6-e6  Qd7-f7  Pf5-f6  Pa5-a4  Qe6-c8  Kg8-h7
>>>                           Pe5-e6  Qf7xf6  Qc8xc7  Kh7-g6
>>>  6 ->   0:01.60   305919   0 turns
>>>  7    654   583  1226489  Qf6-e6  ??
>>>  7    352   742  1585651  Qf6-e6  Qd7xe6  Pf5xe6  Pa5-a4  Pd5-d6  Pc7xd6
>>>                           Pe5xd6  Kg8-f8  Pd6-d7  Kf8-e7  Pd7-d8B  Ke7xd8
>>>                           Ph2-h4  Kd8-e7
>>>  7    357   762  1623830  Qf6-g6  !
>>>  7    525   919  1926808  Qf6-g6  Kg8-f8  Qg6-h6  Kf8-g8  Qh6-g5  Kg8-f8
>>>                           Kh1-g1  Qd7xd5
>>>  7 ->   0:10.26  2108193   1 turn
>>>  8    525  1161  2360687  Qf6-g6  Kg8-f8  Qg6-h6  Kf8-g8  Qh6-g5
>>>  8 ->   0:23.94  4694659   0 turns
>>>  9    525  2935  5710337  Qf6-g6  Kg8-f8  Qg6-h6  Kf8-g8  Qh6-g5
>>>  9    526  3916  7666834  Qf6-g5  Kg8-f8  Pd5-d6  Pc7xd6
>>>  9 ->   1:10.73 13328419   1 turn
>>> 10    526  8747 16329005  Qf6-g5  Kg8-f8  Pd5-d6  Pc7xd6  Pe5-e6  Qd7-b7
>>>                           Kh1-g1  Qb7-g7  Qg5xg7  Kf8xg7  Pe6-e7  Kg7-f7
>>> 10 ->   3:58.68 42938008   0 turns
>>> 11    526 40425 71196909  Qf6-g5  Kg8-f8  Pd5-d6  Pc7xd6  Qg5-h6  Kf8-g8
>>>                           Pe5-e6  Qd7-b7  Kh1-g1  Qb7-g7
>>> 11 ->  17:32.80 184157117   0 turns
>>
>>So that's 7.62 seconds to switch to a different move.
>>Phalanx has special knowledge that helps it to see
>>those things quickly. It has huge extensions (like several
>>full plies) on piece exchanges leading to pawn-only endgames.
>
>I had not noticed how quickly Phalanx switched off from Qe6+.  I wonder if Qg5
>is a better choice than e6, which is what all the other engines were choosing.
>
>It has a higher evaluation, but the reported search depth is not great.  I might
>let this one run 24 hours just for fun

Just try if you have a machine available. I cannot do it
as i am about 2000 km away from my computers. I'm now
on a professional training in Helsinki trying hard to
keep attention :-)

Of course Qg5 is better as black cannot exchange the Q.

The extension trick should be working anywhere in the tree.
It might give about 4 plies for the Q exchange in this case.

Dusan



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