Author: Uri Blass
Date: 03:06:01 01/04/03
Go up one level in this thread
On January 04, 2003 at 05:20:14, Ed Schröder wrote: >On January 04, 2003 at 04:34:37, Uri Blass wrote: > >>1)It seems that Ed missed the following post >>http://www.talkchess.com/forums/1/message.html?274444 > >Okay. > > >>2)I have questions about the recapture extensions. >> >>a)I think that it is more simple to use >> >>HIGH = root_score+TABLE [current_depth]; >> >>static int TABLE 500,500,450,400,350,300,275,250,225,200,200,.... > >I suppose you can do it this way too, yes. > > >>By this way you do not need to update high every ply but only calculate >>it after recapture. > >Hmmm..., why make easy things complicate, it's only done one time when going one >ply deeper in the tree at the very begining of the new ply, and when climbing >back, meaning its costs are zero. I agree that it is still cheap. but doing it every time you make move or undo move is still more work to do then doing it every time you make or undo moves. > > > >>b)What do you mean by I_score >>Is is the score after the recapture or before the recapture. > >I_SCORE is material value (plus PS values) of the current board position. Yes but it is not clear for me if the current board position is before the recapture or after the recapture. > > > >>I think that it may be productive if you demonstrate by a diagram what is the >>value of I_score. >> >>suppose you search from the opening position >>1.e4 e5 2.Nf3 Nc6 3.Bb5 Nc6 Bxc6 dxc6 > >Where is the diagram :) The first diagram is the diagram of the opening position(the root of the search) [D]rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 The second diagram after 4.Bxc6 dxc6 is the following diagram [D]r1bqkbnr/1pp2ppp/p1p5/4p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 0 5 I guess that Rebel does the recapture extensions. > > >>I guess that a recapture extensions is done. >>Assume that the initial position has 0.00 evaluation. >> >>What is the value of high?(I am not sure if 2.5 or 2.25) > >ply 7 -> 2.50 >ply 8 -> 2.25 >ply 9 -> 2.00 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Bxc6 dxc6 I guess that the position after 4...dxc6 is ply 8 and I guess that the currecnt board position is the position after 4...dxc6 so it is 2.25. > > >>Ignore the fact that bishop and knight may have the same value. >>Is piece_value depth the value of bishop or knight when the recapture extension >>is done(I guess bishop)? > >I don't understand your question. The question is if piece_value after the captures BxN PxB is the value of the bishop or the value of the knight. > > >>Is I_score the score before dxc6 or after dxc6? >>Is I_score from the point of view of the side to move or from the point of view >>of the opponent? > >Again, I_SCORE is material value (plus PS values) of the current board position. > >Ed I understood it. The question is if it is from the point of view of the side to move. I always use it from the point view of the side to move but I have doubts if it is done in that way in Rebel after I did not understand another subject about pruning in the qsearch when for me the logical way is to prune when score <alpha-something and for you it is >beta+something. I may look at your other reply that you probably replied to see if you answered it. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.