Author: Ulrich Tuerke
Date: 14:53:11 06/25/02
Go up one level in this thread
On June 25, 2002 at 17:42:58, Tony Werten wrote: >On June 25, 2002 at 17:30:51, Ulrich Tuerke wrote: > >>On June 25, 2002 at 02:40:59, Gian-Carlo Pascutto wrote: >> >>>On June 24, 2002 at 18:53:24, Steve Coladonato wrote: >>> >>>>>I wonder what you consider 'comparable'. There's no guarantee >>>>>they'll be similar whatsoever. >>>> >>>>That was not a well formed statement on my part. What I meant was that for a >>>>given ply depth, the evaluation that program X comes up with should be >>>>comparable to the evaluation that program Y comes up with if both programs are >>>>fairly equal in overall strength. >>> >>>No. There is no guarantee whatsoever that this is true. >>> >>>>Therefore, if the algorithms/heuristics that >>>>program X uses allow it to get to ply M faster than program Y, then program X >>>>should win if the time allowed constrains how much time each program can use for >>>>analysis at that depth. For example, if program X can get to ply 11 in 30 secs >>>>and program Y takes 1 min 30 secs to get there, the overall analysis that >>>>program X can generate during a game should be better than that generated by >>>>program Y and program X should win. So it seems that the efficiency of the >>>>algorithms/heuristics will determine the overall strength of a program. >>> >>>Again, this is completely false. >>> >>>I will repeat what I said several times earlier in this thread, and that >>>is that plies are not comparable between chessprograms. The analysis of >>>one program at ply 11 can be completely different and of higher >>>quality than another at the same 11 ply. If the second program reaches >>>ply 11 faster, we have no information at all to make any solid conclusions >>>about the relative strength of those programs. >> >>Completely agreed. This integer which we are talking about should be better >>called "iteration number". It basically defines how many times the search had >>been restarted exploiting each time the results of the preceeding iteration in >>order to extend the search tree. >>IMHO, the relation of iteration number to search depth is a very loose one, >>having in mind that todays programs are heavily pruning as well as extending. >> > >Hmm. I can imagine that a program that uses partial ply extensions might decide, >when the timelimit is almost reached, to start an iteration with only half a ply >deeper. > >Or even worse. Every uses iterative deepening, but did anybody ever prove that >full plies are best ? Maybe 2/3 ply is better ? I think, that I have heard that Junior uses 2 iterations in order to deepen by one ply. A long time ago, when watching the main line of David Lang's good old Psion chess, it seemed to me that David deepens by 2 plies per iteration in Psion Chess. The length of its PV grew like 3, 5, 7, ... iirc. Uli > >Tony > >>Uli >> >>> >>>-- >>>GCP
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.