Author: Robert Hyatt
Date: 20:15:53 01/07/00
Go up one level in this thread
On January 07, 2000 at 18:45:14, Landon Rabern wrote: >On January 07, 2000 at 12:25:46, Robert Hyatt wrote: > >>On January 07, 2000 at 03:56:37, Landon Rabern wrote: >> >>>I jsut added a q-search to my program and it dropped from 180,000 nps to >>>90,000 nps. I count leaf nodes when counting my nodes, so I though it might be >>>that the q-search has no leaf nodes, so I was not getting these free no-work >>>nodes. This wasn't it though, because I tried incrementing the nope counter >>>where a leaf node would have been had it been a regular search, but this only >>>improved it slightly. I am pretty sure that it is actually running a lot >>>slower. Is it supposed to do this? >>> >>>Thanks, >>> >>>Landon W. Rabern >> >> >>The issue is how do you generate captures. If you generate all moves, and >>then extract the captures for the q-search, your nps must drop, because of >>all the extra work you do but never take advantage of. The q-search is >>more selective, meaning that for each node you reach in the q-search, you do >>the usual amount of work in the alpha/beta search, and so forth, but you only >>look at a couple of branches. That drops the NPS significantly. > > >I generate only captures and only use the captures that are "good" meaning that >the piece capturing is worth the same or less than the one captured. Do you >think adding the captured king method of testing for check in the q-search will >about even things out? > >Landon W. Rabern No. At internal nodes, you do all the alpha/beta work, the procedure call to search, etc, and ammortize that over a bunch of moves. In the q-search, you do the same sort of set-up work, but ammortize it over a couple of moves at most. NPS must go down....
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