Author: Robert Hyatt
Date: 06:11:18 07/13/00
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On July 12, 2000 at 22:57:29, Dann Corbit wrote: >On July 12, 2000 at 21:57:07, Robert Hyatt wrote: >[snip] >>I don't see how to do that. The CAP data is composed of _very_ deep searches. >>While building a book from millions of games, there is _no way_ to do searching >>at each point in the tree. Even at 1 second per search, 2 million games has >>something like 160 million moves. Doing 160M 1 second searches will take a >>_long_ time. And 1 second is _not_ reliable for choosing book moves. > >In my 2.4 million games, there are about 150 million positions that have been >played. Let's prune back to only consider the 60 million most important. > >We will build a tree with branches using a variable sized array with a technique >similar to that of a skiplist. > >Only one character needs to be stored for each move forward from the root (the >normal chess starting position). We simply sort all possible moves generated >and give the number of a given move as an unsigned char from 0 to 255. We will >also store a two byte ce, and ebm [extrapolated bm] and bm will require an >additional two bytes. before you go on, we are on two different pages. When I said "search" I meant a tree search. The suggestion was to do searches in positions where there is no CAP score, when minimaxing the book. I was pointing out that the typical book is so large, that even 1 second searches make this undoable. Not searching thru the book to minimax it. But searching the millions of positions where there is no CAP score. > >A few hundred megabytes will store the entire tree in memory. Certainly less >than a gigabyte. A recursive tree walker could propagate window information >back up to higher levels. Now, while this won't be the same as a mini-max, we >can use the data to narrow the window or tag a choice as definitely wrong. For >those that are clearly wrong, we can reevaluate using some other technique. > >It may also be possible to evaluate the tree using a SQL database. Given a 3090 >with a Gig of ram and a few hundred gigs of disk, it might be runnable over a >weekend.
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