Author: Steven Edwards
Date: 23:12:13 05/24/05
Go up one level in this thread
On May 24, 2005 at 18:49:05, Michael Yee wrote: >Schaeffer essentially computes piece square table "bonuses" that depend on the >root position (e.g., plans like "king-side attack" or "try to occupy f5 with >your knight") and get added to the score of a branch in a path dependent way. > >Some questions: >(2) Does anyone know how Schaeffer's Planner compared to Wilkin's PARADISE (in >terms of playing strength)? The only strength data point on Paradise is that it performed better on tactical problems than either Chess 4.x or Tech II (given a significant time advantage (45 minutes vs. 5 minutes per position). If the ChessLisp interpreter had been available, the time advantage would have been unneeded. My understandng is that the output of Schaeffer's Planner was limited to a set of twelve piece/square tables used in leaf node evaluations. This was generated once, at the root node only. Paradise generated a relatively complex plan that was then used as a search control program. Plans would also be generated at other nodes when needed, and a variety of other somewhat advanced techniques (e.g., a causality facility) were used to assist with the search. Schaeffer's root preprocessing work is interesting in that it's initial phase of long term goal selection is similar to Symbolic's KsSurveyor theme selection. Any planning program will need such a component. Symbolic has the capability (and the requirement) to potentially apply the theme selection at any node, not just at the root. Generating piece/square evaluation tables at the root and expecting them to be of much use a dozen plies later is unrealistic. >(3) Is anyone experimenting with this or other types of path dependent eval? > >Steven is of course working on long-range planning. And I think Uri has some >path dependent stuff. But have most people pretty much abandoned it? Instead of calling it "path dependent eval"', I prefer saying "root preprocessing" meaning that it's a one time task done only at the root position. Symbolic, like Paradise, has a recursive planner that can be potentially applied at any node and is not limited to the root position. In fact, if an obvious move is available in the root position then the planner will never be invoked.
This page took 0.01 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.