Author: Gerd Isenberg
Date: 12:21:22 07/24/04
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On July 23, 2004 at 19:59:03, Dann Corbit wrote: >Similar to what I like to do. >Use the linear "select top N" function I posted in the "find min" thread to >collect the top k entries. (I like k=4 or 5). Then I use a special function to >sort the top k items using minimal comparisons and exchanges (a tiny fixed >number of operations). >The other N-k entries can remain unsorted, or you can repeat the process on the >N-k entries if you never get a big fail-high (if you like.) > >Expected time: O(n), with top 4 or 5 items in proper sort order. Good idea! If first five moves don't fail high in cut-nodes, how high is the probability that a remaining move fails high or that the cut-node becomes an all-node? Is it worth to keep track of pv/cut/all-nodes (pv is most left, cut-nodes are siblings of pv-nodes or child of all-nodes, all-nodes child of cut-nodes) and to distinguish them in scoring and getting? What i actually do in my 32-bit program is generating moves with a kind of finite state machine. So i first try to only generate hash move, obvious winning captures, killers and safe checks. If no such move (if any) results in an cutoff, i start to generate other moves and score and pick them depending on eval versus alpha. That works fine, but is complicated and has the disadvantage to keep some additional data, such as state of movegen and bookholding-information in each node. Gerd
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