Author: Bas Hamstra
Date: 17:25:53 01/16/01
Go up one level in this thread
On January 15, 2001 at 21:33:02, Christophe Theron wrote: >On January 15, 2001 at 18:24:23, Bas Hamstra wrote: > >>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. >> >>They can also be very powerful, see Genius. It sees amazing things in 0 sec. So >>it can be done. > > > >Unfortunately this has nothing to do with fractional extensions. I was referring to extending more than 1 ply. Bas. > > > Christophe > > > > >> What about this, heavy extend near the root until 100.000 (or >>whatever) nodes are reached. Works brillantly. No choking. And then comes the >>deep search and the hashtable is full of nice things. >> >>Bas.
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