Author: Gerd Isenberg
Date: 15:30:56 09/15/04
Go up one level in this thread
<snip> >>>I guess with a counter of played pv-moves (0..N) in the top of the current path >>>and ply index one may determine the minimal tree node type as well... >>>So we have distance D of the current node to the last pv node in the current >>>path. >>> >>>If D == zero we have a pv-node. >>>If D is odd we have a cut node. >>>If D is even and greater zero we have an all node. > >That is crude. The problem is that suppose you are wrong at ply=2. That causes >you to mis-categorize every node below that because when you are wrong at ply=2, >for non-PV ply=1 moves, it suggests that either the current ply-1 move is better >than the best so far and you are changing your mind, or that the current ply=2 >move is not the best and another move will cause a cutoff. But below that ply=2 >move that is normally a CUT node, ply=3 would normally be an ALL node, but that >changes since the ply=2 node is wrong. > i mean a minimal tree in that way: p(v), c(ut) and a(ll) nodes, the numbers behind the distance to a pv-node, cut node numbers are odd. ply 0 p0 1 p0 c1 2 p0 c1 a2 a2 3 p0 c1 a2 a2 c3 c3 c3 c3 4 p0 c1 a2 a2 c3 c3 c3 c3 a4 a4 a4 a4 a4 a4 a4 a4 >This was one of the many categorizing things I did in the Cray Blitz DTS "where >to split" code to try to be sure I hit on an ALL node, not a CUT node. > >>> >>> >>>> >>>>>E.g. if static eval <= alpha or even first move doesn't improve alpha? >>>>> >>>>>Thanks, >>>>>Gerd
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.