Search found 845 matches

by phhnguyen
Sun Sep 09, 2012 9:20 am
Forum: Computer Chess Club: General Topics
Topic: Koala - a free chess endgame 3-4 men for IOS devides
Replies: 2
Views: 781

Koala - a free chess endgame 3-4 men for IOS devides

Hi everyone, Several years ago I had created some endgames for Xiangqi (Chinese chess) and a program (named EON) work with them as an endgame dictionary / solver. That program could show all games from a given endgame for users to select and view, display their results (draw or mate/lose in n moves)...
by phhnguyen
Sun Sep 09, 2012 9:13 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

I think we may save for some endgames but not all if using DTC instead of DTM. The problem is still serious. If you loosen the requirement of finding the shortest path to mate to finding a winning path to mate, you can get rid of the large DTM tables and instead use a combination of bitbases (for p...
by phhnguyen
Sat Sep 08, 2012 4:49 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

For example, for KRNKB, the search can reach easily depths 10-12 in reasonable time, but then too slow to go deeper and I don't think it can reach to depth 50 which needed for that endgame even in hours. I think you misunderstood the need for searching. It is not to resolve the endgame position by ...
by phhnguyen
Sat Sep 08, 2012 4:38 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

To reach depth 50 with alpha beta you're going to need massive amounts of pruning, an amount that's probably not attainable with just a WDL table for a generally won endgame. Thank you. Now I feel confident with my current work (not doing something too silly). Bitbase and WDL information seems be n...
by phhnguyen
Fri Sep 07, 2012 7:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

I am still working on my search function for bitbases but facing a big problem of heavy explosion. At this moment, my search function is closed to a normal alpha-beta search (it uses hashtable, null move, pv, but there are not qs nor evaluation functions). All necessary endgames (bitbases for 5 men,...
by phhnguyen
Wed Sep 05, 2012 3:10 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

I have been on the step of implement normal search for probing bitbase (before that, I use a simple search which mainly looks into endgames for values). Just have another considering / confuse: implementations of qs and evaluation functions. For the task of retrieving mate scores (full DTM) from bit...
by phhnguyen
Wed Sep 05, 2012 2:14 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

E.g. KBNK is always won if there is no shallow tactical loss of one of your pieces (bare K forking B & N). This is not entirely correct (or at least it's not easy to detect when there is a tactical loss). It took me many hours to test & write correct rules for KBNK endgame. Just one example of a tr...
by phhnguyen
Wed Sep 05, 2012 2:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

Thank you for your reply. I have spent quite some time with how to make progress with bitbases alone. Here is a summary. For further info, look into scorpio source code. I have known Scorpio and its bitbase for long time (I have read almost all posts about bitbases on this forum, including Scorpio)....
by phhnguyen
Wed Sep 05, 2012 8:21 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search with bitbase
Replies: 17
Views: 3486

Re: Search with bitbase

It depends on your goal: do you really want to play the shortest path to mate, and announce its length, or do you just want to win? Thanks for your answer. My current app will be kind of problem solver / endgame looker, thus win/loss values are not enough but it needs to extract full values of DTM....