Sorting losing captures ?

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MahmoudUthman
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Sorting losing captures ?

Post by MahmoudUthman » Sat Feb 25, 2017 9:54 pm

What is the best technique for sorting losing captures ?

jdart
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Location: http://www.arasanchess.org

Re: Sorting losing captures ?

Post by jdart » Sat Feb 25, 2017 10:27 pm

I sort by MVV/LVA and then when the move is actually being used, if it is a capture, I do SEE and if the score is negative the move is deferred - it goes into a "losing capures" array and moves are fetched out of there only at the end of move generation, assuming the search ever gets there.

--Jon

MahmoudUthman
Posts: 234
Joined: Sat Jan 17, 2015 10:54 pm

Re: Sorting losing captures ?

Post by MahmoudUthman » Sat Feb 25, 2017 10:46 pm

jdart wrote:I sort by MVV/LVA and then when the move is actually being used, if it is a capture, I do SEE and if the score is negative the move is deferred - it goes into a "losing capures" array and moves are fetched out of there only at the end of move generation, assuming the search ever gets there.

--Jon
have you tried the same thing using just MVV in the main search ?

jdart
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Re: Sorting losing captures ?

Post by jdart » Sat Feb 25, 2017 11:39 pm

have you tried the same thing using just MVV in the main search ?
No, I have not.

--Jon

Ferdy
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Re: Sorting losing captures ?

Post by Ferdy » Mon Feb 27, 2017 2:16 am

MahmoudUthman wrote:What is the best technique for sorting losing captures ?
Long ago I tried the following. I am not claiming it is the best :).

Code: Select all

Deuterium
Version 09.01.26.492 (21Dec09)

[...]

8. Added capture killer moves, these are lossing capture moves that produces a cutoff.

[...]

Henk
Posts: 5816
Joined: Mon May 27, 2013 8:31 am

Re: Sorting losing captures ?

Post by Henk » Mon Feb 27, 2017 9:27 am

How do you know if a losing capture is not winning sacrifice ? So only near the leaves losing captures are applicable.

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Evert
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Re: Sorting losing captures ?

Post by Evert » Mon Feb 27, 2017 12:09 pm

Ferdy wrote: Long ago I tried the following. I am not claiming it is the best :).

Code: Select all

Deuterium
Version 09.01.26.492 (21Dec09)

[...]

8. Added capture killer moves, these are lossing capture moves that produces a cutoff.

[...]
I have experimented with that too, but the results I found were not very convincing.

Volker Annuss
Posts: 173
Joined: Mon Sep 03, 2007 7:15 am

Re: Sorting losing captures ?

Post by Volker Annuss » Tue Feb 28, 2017 6:24 pm

Ferdy wrote:Long ago I tried the following. I am not claiming it is the best :).

Code: Select all

Deuterium
Version 09.01.26.492 (21Dec09)

[...]

8. Added capture killer moves, these are lossing capture moves that produces a cutoff.

[...]
Making captures killers works for me. The only captures that are excluded from killers are moves that capture the last moved piece.

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