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Subject: Re: Completely blocked positions, some interesting things

Author: Omid David

Date: 05:03:19 10/04/02

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On October 04, 2002 at 06:30:02, Omid David wrote:

>On October 03, 2002 at 22:47:58, Jeremiah Penery wrote:
>
>>On October 03, 2002 at 22:07:38, Omid David wrote:
>>
>>>On October 03, 2002 at 21:30:56, Jeremiah Penery wrote:
>>>
>>>>On October 03, 2002 at 20:39:02, Omid David wrote:
>>>>
>>>>>Quite impressive, just 1.02% slower (paractically negligible). Do you invoke
>>>>>that detection at every node in the search tree?
>>>>
>>>>Yes, but most of the time it exits very quickly (a couple of 'if' clauses).  I
>>>>could probably make it cost even less, but I'm not very interested in doing that
>>>>yet.
>>>
>>>But the problem may arise in the endgames where there are a number of pawns and
>>>pieces left which can potentially cause a "block draw". Then in the draw
>>>detection heuristic, almost in every node you'll pass the first few 'if's and
>>>will have to step into a detailed assessment of the position. How much does it
>>>slow down there, in comparison to the non-detecting version?
>>
>>I'm not really sure, and I suspect it depends highly on the kind of position.
>>If you have any specific ones, I'll be happy to test them.
>>
>
>Let's compare the following two very similar positions:
>
>The first one - White wins:
>[D] 8/8/8/k3p3/1p1pPp2/1PpP1P2/K1P3B1/8 w - - 0 1
>
>The second one - Draw:
>[D] 8/8/8/k3p1p1/1p1pPpP1/1PpP1P2/K1P3B1/8 w - - 0 1
>
>How do the different methods fare in these two cases?

And a third position which is also a draw:

[D] 8/8/8/k3p3/1p1pPp2/1PpP1P2/B1P5/1K6 w - - 0 1






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