## Search found 194 matches

Fri Apr 26, 2013 5:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Free Bitboard Viewing Utility...
Replies: 15
Views: 3342

### Re: Free Bitboard Viewing Utility...

Yes, thats why you can use >>> to bring in 0's, or >> to bring in 1's (if its already negative).
Fri Apr 26, 2013 5:45 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Free Bitboard Viewing Utility...
Replies: 15
Views: 3342

### Re: Free Bitboard Viewing Utility...

Well that's true in C, but I'm using java.

A "long (64 bit)" in java is from -2^63 to 2^63-1, so I don't think I have any other choice but to use negatives (when the highest bit is 1).

It makes no difference to my code, but I would have to use that bitboard tool with caution.
Fri Apr 26, 2013 4:13 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Free Bitboard Viewing Utility...
Replies: 15
Views: 3342

### Re: Free Bitboard Viewing Utility...

I like this browser version tool: http://butterflychess.altervista.org/bitboard_calculator/Calc.html?type=0 But I found a small problem with it.. The highest bit(63) has decimal value 2^63, But I'm guessing typical programming languages would use -2^63 for this bit, to give the nice range -2^63 ... ...
Mon Jan 02, 2012 11:46 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

Ok, In the without case, I just generate all captures, order them by MVVLVA. Then I skip over them if... if (val + value(captured)+ 150 < alpha) skipmove; I did have K as 7, but I just changed it to 0, since I assumed king capturing pieces would be better than any other piece as the ...
Mon Jan 02, 2012 8:24 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

Yes, I have... if ( value(captured) >= value(capturer) || SEE( move ) >= 0) ) So negative SEE's are ignored. But the total nodes searched is actually 2% more using SEE, than without (With the position 1kr5/qnrbb3/4n3/1ppp4/1PPP4/BN2NB2/1QR5/1KR5 b - - 0 1 at 13 ply search), I...
Mon Jan 02, 2012 1:26 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

Thanks, I actually already had the int val = getEval(); if ( val >= beta ) return beta; ///// if ( val > alpha ) alpha = val; ///// I must have accidently skipped over those lines while I was copy and pasting my code in here. The code you wrote is effectively what I have now which is a little sl...
Mon Jan 02, 2012 3:50 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

Thanks that helps... I more or less get it now after analysing a couple of trees. In the QS, I ordered by MVVLVA, then applied see when value(capturer) > value(captured) But its still about 20% slower compared to just using MVVLVA. I did a count in qs for a 14 ply deep search of: 2r5/qnrbb3/k3n3/1pp...
Sun Jan 01, 2012 2:56 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

Thanks, do you mean history heuristic?

I've heard of it, but not implemented it, I have hash table, and iterative deepening, and also null move currently.

You're time for a3 is excellent, I will be very happy if I can get time like that one day before I die (using same hardware)
Sun Jan 01, 2012 1:58 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

I was doing it just for move ordering, I assumed that was what it was meant for. I think my QS is messed up, I gotta go over some alpha-beta pruning again so I can refamiliarise myself with how it works. I get the principle of cut-offs, but I get a bit confused with the alpha-beta window, so probabl...
Sat Dec 31, 2011 4:22 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: SEE is too slow
Replies: 34
Views: 6292

### Re: SEE is too slow

Excellent, I was thinking something like that before, like P x R, is always gonna be good. In this case, we get the 500 for the rook, and maybe or maybe not lose the 100. So just to be clear, in the case above, your saying.. score_for_sort[j] = 500 - (100 >> 3); I think >> 3 is the same as dividing ...