Author: Robert Hyatt
Date: 07:45:07 09/28/04
Go up one level in this thread
On September 28, 2004 at 05:17:26, Peter Fendrich wrote: >On September 27, 2004 at 23:45:54, Stuart Cracraft wrote: > >>I experimented with reordering root ply at iterative depth iply > 1 >>where 1 is the root ply, with the results of iply-1 sorted by the >>total nodes of quiescence and main search defined as the # of entries >>for each of those subroutines. >> >>I didn't sort at root node on the first sort by quiescence but instead >>by my normal scheme though I tried quiescence and it was worse. I felt >>this gave a better chance to the above method. >> >>I sorted moves at the root ply for iply > 1 in the following way >>for 7 different parts to the experiment. >> >> sort by normal method (history heuristic, mvv/lva, see, etc. >> sort exactly by subtree node count, nothing else >> sort by subtree node count added to normal score (hh, mvv/lva, see, etc.) >> same as previous but node count x 10 before addition >> same as previous but node count x 100 before addition >> same as previous but node count x 1000 before addition >> same as previous but node count x 10000 before addition >> >>The results, measured by # right on Win-at-Chess varied from >>250 for the first in the list above to 234 for the last. >>Most bunched up between 244-247 except the first was 250, >>my current best on WAC with handtuning everything. >> >>For me, I'm convinced that this style of sorting root ply is >>slightly less good for my short searches compared to what I am using: >>a combination of history, heuristic, see(), and centrality with >>various bonuses, about a half page of code sprinkled about. >> >>The advantage of sorting root node by subtree is the simplicity. >>It eliminates about a half a page of code and introduces >>about a quarter page of code for only slightly lesser results >>(within 1-2% of my current result) so that is good. >> >>Still I think I'll leave it #ifdefed out for now and use it as >>a baseline that is only improvable upon with handtuning of my >>current methods and others to be discovered. >> >>Stuart > >I've noticed that you often refer to WAC and also do very quick searches. >If you get 247 in one test and 250 in another that doesn't mean a thing >if you don't examine the positions that changed. Very often you will find that >the difference is due to random coincidents. >I'm sure that you could get such differences just by making some innocent change >somewhere in the code... Correct. Change the move ordering. Change the hash table order of storing things. Occasionally change the best move or score as a result. 1 sec WAC runs is not the way to test for performance, particularly when 1 sec really means 1 sec +/- N where N is a non-trivial amount of quantization error in timing... >There will always be some part of your move ordering (in the tree) that is >random and the same goes for what positions and moves that happens to stay in >the hash table, killer- and history-lists. >/Peter
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