Author: Christophe Theron
Date: 10:06:13 01/14/01
Go up one level in this thread
On January 14, 2001 at 10:18:08, Robert Hyatt wrote:
>On January 14, 2001 at 00:37:12, Christophe Theron wrote:
>
>>On January 14, 2001 at 00:22:17, Robert Hyatt wrote:
>>
>>>On January 14, 2001 at 00:05:08, Christophe Theron wrote:
>>>
>>>>On January 13, 2001 at 17:19:19, Robert Hyatt wrote:
>>>>
>>>>>On January 13, 2001 at 17:13:13, Gian-Carlo Pascutto wrote:
>>>>>
>>>>>>Hi all,
>>>>>>
>>>>>>I just added code to my program to handle fractional extensions
>>>>>>and recapture extensions.
>>>>>>
>>>>>>My problem now is: how do I test & tune these? I did what I
>>>>>>normally do and ran it through WAC. It did worse. Probably not
>>>>>>so surprising as they are nearly all rather simple tactical
>>>>>>positions, so extending more (on checks...not so much on
>>>>>>recaptures) is nearly always a win.
>>>>>>
>>>>>>Does anybody here have a testcase? Maybe a set of positions
>>>>>>where it _really_ matters how you do your extensions?
>>>>>>
>>>>>>If you added frac. extensions you your program, what made you
>>>>>>decide to do so?
>>>>>>
>>>>>>--
>>>>>>GCP
>>>>>
>>>>>
>>>>>Do as I did. Make the extension amount something you can set via command.
>>>>>Then run a potload of tests. I ran WAC with all the extensions set to
>>>>>values between .5 and 1.0, in increments of .25. That is 3 cases for
>>>>>each extension and I varied 4 different extensions. 81 tests and you then
>>>>>look at which ones needed the fewest total nodes to solve _all_ the test
>>>>>positions...
>>>>
>>>>
>>>>
>>>>
>>>>So Crafty is cooked for WAC!? ;)
>>>>
>>>>
>>>>
>>>> Christophe
>>>
>>>
>>>:)
>>>
>>>actually not, as I used a lot of other positions as well (IE I used some of
>>>the "crafty goes deep" positions that were not tactical at all....)
>>
>>
>>
>>I am still using full ply extensions.
>>
>>I think I should try fractional extensions. Actually I did in the past. My 16
>>bits version used fractional extensions (in 1/100th of ply), but I was also
>>doing much more extensions. I mean I had more reasons to do extensions.
>>
>>As for now, I prefer to be extremely "selective" in my extensions. There are a
>>lot of conditions to meet before Tiger triggers an extension.
>>
>>
>>
>> Christophe
>
>
>Fractional ply extensions give a chance for better control. IE you can say
>"OK, I want to extend 3 checks, then not extend 1, then extend the next three,
>but not the next... then you use a 3/4 ply extension... it is also useful
>for controlling the one-legal-reply extension since that is really a double
>extension on one ply and extending _two_ plies is potentially catastrophic.
I'm currently doing something similar by updating a flag word. The flags
basically tell me what happened in the current path and I use it to make
extension decisions.
Christophe
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