Author: Dave Gomboc
Date: 11:34:24 11/27/02
Go up one level in this thread
On November 27, 2002 at 10:01:02, David Rasmussen wrote: >I've been thinking the same thing. >It is certainly true, that you can traverse the same tree by an infinity of >search schemes. For example, a 5 ply nominal search with some extensions to, >say, 9 ply, can be regarded as, say, a 7 ply "nominal" search, with the boring >lines (i.e. those that did not get extended from 5 ply) pruned. The same goes >for qsearch. In principle, you could skip your qsearch, and just have some >clever extensions that did the same. But what does this all boil down to? This: >qsearch _is_ just a clever extension scheme, if you regard it that way. The >question is: What is the easiest way (and in practice, speed also counts) to >specify what tree you want? I think it is probably much easier to have the >traditional design of separate search and qsearch, compared to combining the >two. A similar question can be asked with regard two extension and pruning. I >guess the main point is: design does matter. It might be much easier to express >something as an extension, than as the corresponding pruning of all other moves, >and vice versa. Design _does_ matter. > >Some time ago, along the lines of these thoughts, I proposed "negative >extensions". That is, if you can somehow classify a move as "probably not >interesting", you can "extend" the depth by -1 or -0.75 or whatever seems >reasonable. Exactly as you do with normal extensions. The good thing about this >is that nothing gets pruned for good, everything will eventually get searched >with iterative deepening, but you search what you think is interesting first. >When I proposed it, a lot of people compared it to null move, which is an >entirely different thing. Also, some people didn't think the idea was >worthwhile. I think it is a good idea, as I think some things are easier >expressed in negative terms: This looks boring, so I will not look so deeply >into to it now. > >Of course, it's just too bad that I haven't gotten around to implementing it >yet. Someone will probably beat me to it. > >/David IMO, q-search is an anachronism and should be abolished. (1/2 :-) People already use search reductions (negative extensions). Dave
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.