Search found 18 matches

by evandam
Tue May 10, 2011 4:44 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Debug issue
Replies: 7
Views: 859

Re: Debug issue

I am not perfectly sure about your exact issue. What I think I understood is that you are observing different node counts for the same search task between old and new engine version, is that right? Yes Are you using hash tables? If so, with fixed zobrist keys? Hash tables are turned off, with the e...
by evandam
Tue May 10, 2011 3:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Debug issue
Replies: 7
Views: 859

Debug issue

A while back I decided to change my board representation to try and gain a little speed. I went from a mailbox representation to 0x88. I took care to make sure that moves where generated in the same order and such. My goal was to have the old engine perform exactly with the new engine and then I cou...
by evandam
Mon Mar 21, 2011 2:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Transposition tables for newbs
Replies: 10
Views: 2109

Re: Transposition tables for newbs

Ok over the weekend I think I got this working much better. At least now the TT version is searching less nodes than the old version. Still not as much as I would have thought, but I think there may still be a few issues. #1. I cannot figure out why with the lower nodes, the best move is stored. I'm...
by evandam
Fri Mar 18, 2011 3:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Transposition tables for newbs
Replies: 10
Views: 2109

Re: Transposition tables for newbs

Thanks Robert, I think I was very close, but you did clear some things up. Something is still not right because my version without the TT is searching less nodes. I suspect 2 things. I think my null move search may be hashing moves, which I assume is bad since null moves are illegal. Also and maybe ...
by evandam
Fri Mar 18, 2011 4:54 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Transposition tables for newbs
Replies: 10
Views: 2109

Transposition tables for newbs

So I have been implementing a TT lookup in my chess program. The one thing I have is a Zorbrist hash that is updated incrementally for the board and I'm 100% that it is correctly producing the key. My question I guess is about the different types of nodes and how to use them. Here is what I'm doing ...
by evandam
Fri Mar 04, 2011 7:54 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: What next?
Replies: 13
Views: 2830

Re: What next?

OK so remember when I said my evaluation was "pretty minimal". Well it turns out it was pretty bad too. I changed it and ran against my previous version and was 157-17-27 ! I've now pitted myself against the bottom 4 int the 40/4 CCRL, trying to replicate their test conditions and that is running no...
by evandam
Wed Mar 02, 2011 5:45 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: What next?
Replies: 13
Views: 2830

Re: What next?

OK the MVVLVA is complete. Some initial tests look good. I tested the time and nodes searched for a depth of 4 of the first 20 silent but deadly epd test positions. %faster %fewer nodes -19.1% -21.1% -22.1% -21.0% -26.3% -30.2% 57.4% -2.9% -82.3% -82.1% -42.1% -33.7% -88.4% -89.2% -91.7% -93.0% -7.3...
by evandam
Tue Mar 01, 2011 7:36 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: What next?
Replies: 13
Views: 2830

Re: What next?

Thanks for the tips guys. I started a TTHash in a branch, but went on to MVVLVA instead. That seems to help a bit. I'm also going to look into Null Move Pruning next. The TTHash is still a bit of a mystery. I have the ZHashKey almost done and tested with my make and unmake move functions, but I'm st...
by evandam
Fri Feb 25, 2011 7:56 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: What next?
Replies: 13
Views: 2830

Re: What next?

Another very important thing is a move list. If you scan all 64 squares to examine the board, you are throwing a lot of time in the toilet. I have a piece list which tells me which squares have pieces on them, is this what you mean. I don't differentiate what the piece is, just that there is one th...
by evandam
Fri Feb 25, 2011 7:21 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: What next?
Replies: 13
Views: 2830

What next?

Ok so I have a Friday night to program, but I'm struggling to figure out what to do next. A little background. - square-centric board representation, 10x12 Mailbox to be exact which stores char piece representations. - Alpha Beta search algorithm with queiscene search at terminal nodes. I iterativel...