Alaric

Alaric

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This blog is describing the development of Alaric.

Bitbases

blogPosted by Peter Fendrich Friday, May 11 2007 17:27:14

Currently Alaric has only one bitbase (a complete database of an endgame). The bitbase kpk.dat that you you will get when you download Alaric covers the endgame with King and pawn versus King. It contains one bit for each possible position with '0' for draw and '1' for win - the only 2 results possible in this endgame. That gives about 120000 positions when I use mirroring and some other tricks to keep the size down. Gives about 44 Kb.

I tested a new technique where I combine chess knowledge and trees for the same endgame. Now I need only 4 Kb and it is complete, that is all possible positions are covered by these 4 Kb. I will test also K, R, P vs K, R to see what can be done. If that works out I will complete all 3- and 4-men endgames with the same technique.

5-men? Well let's see how this works out first...
It is quite a manual task to identify what kind of knowledge to use and how to represent it. smiley

My first intention to write a bitbase generator and compress the bitbases as much as possible is somewhat changed. Look here.

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Posted by Peter Fendrich Tuesday, May 15 2007 20:29:45

Well @Permanent Brain, this was more time consuming than I could ever imagine....
Never give up! smiley

Posted by Permanent_Brain Tuesday, May 15 2007 17:37:16

Hi :-) I think it's a good idea to make tests towards KRP-KR bitbases. This is probably the most important 5-piece endgame for the practise, and to have database support for it, may result in most of the strength increasement which bitbases can provide at all, in total.

I have tested Alaric 702 and 703, and I think it is one of the "quality" engines, comparable to Delfi or Colossus, which are in a kind of waiting position to join the very top, soon. I will keep being interested. Thanks for your efforts.