Search found 224 matches

by outAtime
Wed Feb 02, 2011 12:55 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: pawn attacks in mobility
Replies: 6
Views: 1944

Re: pawn attacks in mobility

I often wondered if it would hurt not to count captures at all. (Mainly because it made incremental update of mobility more difficult.) Captures are more often bad than not. If they were good, they would already have been made earlier, or the position is not quiet now. If they are bad, they'd bette...
by outAtime
Wed Feb 02, 2011 12:24 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: low scores for pawn weaknesses
Replies: 1
Views: 864

low scores for pawn weaknesses

Can anybody explain how Gull (an interesting and strong playing program) gets away with such low scores for pawn weaknesses? This to me seems against the grain of all other programs I have had the pleasure to study, be it Stockfish or Fruit, or Crafty etc.. From Gull: const int PawnUP[8] = {0, ...
by outAtime
Sun Jan 30, 2011 5:46 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: pawn attacks in mobility
Replies: 6
Views: 1944

Re: pawn attacks in mobility

What is so special about Bishop attacks? Surely I have seen examples of a well posted knight which cannot be driven away, yet attacks nothing therefore having little function (value). Maybe only including unoccupied squares in the mobility scores does not do enough to guarantee the piece is not just...
by outAtime
Sun Jan 30, 2011 5:30 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: pawn attacks in mobility
Replies: 6
Views: 1944

Re: pawn attacks in mobility

I think i saw somewhere an idea where different attacks (captures) were given more weight than others in mobility according to piece type and also the type of piece attacked. It seems to make some sense logically to give different bonuses in this way, but I can't see where counting only empty square...
by outAtime
Sat Jan 29, 2011 9:16 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: pawn attacks in mobility
Replies: 6
Views: 1944

Re: pawn attacks in mobility

I guess i shouldn't count protected pawns either..
by outAtime
Sat Jan 29, 2011 9:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: pawn attacks in mobility
Replies: 6
Views: 1944

pawn attacks in mobility

Hi, Ive been trying to get mobility to stop counting squares which are attacked by opponent pawns as mobile. This code seems to work but Im wondering if it cant be improved or if someone can spot a bug somewhere. Im not sure how many games I would need to run to tell if this is an improvement or not...
by outAtime
Wed Jan 26, 2011 10:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Gull
Replies: 2
Views: 985

Gull

Having a look at Gull and noticed some strange mobility code for bishops.. score += choose_popcnt<HPopCnt>((~Board->bb[White]) & att & BishopMajorWhite) * BishopMobMajor where BishopMajorWhite is: #define BishopMajorWhite Convert(0x7EFFFF7E3C000000,uint64) Can anyone explain what is bein...
by outAtime
Fri Jan 21, 2011 4:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Futility Methods
Replies: 4
Views: 1748

Re: Futility Methods

ok, great, thankyou very much! This should be correct then: if (fut_score == INF) { fut_score = eval() + FUT_MARGIN; assert(fut_score < INF); } score = fut_score; /* prune */ if (fut_score <= alpha) { if (score > best_score) { best_score = scor...
by outAtime
Fri Jan 21, 2011 3:44 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Futility Methods
Replies: 4
Views: 1748

Re: Futility Methods

ok, thanks for the reply. Then why do some of these programs update the PV or best_move if score > best score (the ones returning alpha)? Just for move ordering? Is there a benifit to that? Thanks again for the reply.
by outAtime
Fri Jan 21, 2011 3:26 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Futility Methods
Replies: 4
Views: 1748

Futility Methods

There seems to be no standard for Fuility, and I'm trying to figure out the best way to add it to my search. Different examples I've seen only help to confuse... update PV/ don't update PV, use best_move/don't use best move..... fruit if( value > best_value ) { best_value = value; pv_cat...