Author: Robert Hyatt
Date: 10:11:21 01/24/01
Go up one level in this thread
On January 24, 2001 at 13:03:21, Miguel A. Ballicora wrote: >On January 24, 2001 at 03:11:56, Severi Salminen wrote: > >>>I didn't do this in Cray Blitz so there is an alternative. Do the normal >>>search, but each time you search a legal move, inc a counter. When you are >>>done searching all moves, if the counter == 1, there was only one legal one >>>to search. Search it _again_ but one ply deeper... >> >>Sounds time consuming...I hate all these researchs :) I _do_ use a legal move > >It should not be, I think. It is like an internal iterative deepening. >Moreover, it could be faster! couldn't be? > >>counter (for other purposes) but I believe it is faster to generate only legal >>"check evasive" moves as I allready pass the "being in check" information to the >>next ply. > >One question, you people do extend when there is a single move. This is an >extra extension besides "check extensions"? >In other words, if king is in check --> depth+=1 and if there is only one >reply --> depth+=2 (assuming no fractional increments) ? > >Regards, >Miguel > > >> >>Severi I get away with doing two extensions because of a minor oddity in my search. I decided that due to my very simple q-search, I didn't want to make a move at the last ply that would check my opponent, and hand that position over to my q-search. What I do, therefore, is that I extend when I _check_ the other side, rather than waiting until I get to the next ply and extending when I notice I am in check. At the next ply I notice I am in check, call the legal- move generator, and if it produces only one move, I extend there for 1 reply. Note that my 'check' extension is 1.0 plies, but the 1-reply extension is currently .75 plies. When I start the search, I start depth off at 1.5, which means the first 2 1-reply (or any other fractional extension) extensions will actually extend a full ply, but the third won't. From then on, out of a group of four 1-reply positions, three will extend and one won't...
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